HR-16/HR16B Service Manual 1.00 i 03/31/06 HR-16
Contents
1. gt E 47K 5 000043 Rt h E 470K 1 8W 5 000044 1 Rt2 h E 5 1K veW 5 0000522 4 f fR10 021 05 a E 5 0 00 0513 1 R20 E 560 18w 5 ___ 0000561 4 E 56K 1 8W 5 0000562 8 R56 A E 820K uew 5 0000224 1 Rte A L l b MAN 2KsPNSP 006248 1 Re MNN E 24K9PINSIP 006249 1 R93 A 9 E TOPKEYPAD 9211002 1 BOT KEYPAD 921 1004 o o ROUNDRUBBERFEET 68 PIN ASIC SOCKET 412 008 1 017 MAN HR 16 HR16B Service Manual 1 00 19 10 0 Software History DATE VERSION COMMENTS 11 1 87 1 01 12 1 87 1 02 12 14 87 1 03 12 16 87 1 04 12 30 87 1 05 1 4 88 1 06 6 15 88 1 07 1 08 First production release 1 Fixes tape sync output so that when more than four drums are played on the same beat the sync output pulse width does not change 2 Changed MIDI test routine so that an extra byte is sent out before testing MIDI to accommodate 8051s that have indeterminate data in the UART on power up 1 Fixes MIDI Song Pointer input bug that caused the HR 16 to continue from the wrong location if in song mode and a tempo was stored in the2. Checking battery backup Actually sending and receiving MIDI information Saving and loading data from tape Copying full patterns to themselves then to other patterns so that memory becomes completely full this ensures that the 8031 address buss functions correctly as the self test does not take addressing into consideration 6 2 Internal Diagnostics and Hidden Keys Below is a list of the key presses necessary to activate hidden functions Power up while holding ERASE DELETE and RECORD Clear memory Reinitialize system Power up while holding QUANT and MIDI UTIL Self test Hold PATT and press VOICE DAC Adjust mode press STOP to exit Be aware that the self test will erase all internal memory equivalent to reinitializing To perform the internal diagnostics connect a MIDI cable between MIDI in and out Connect a 1 8 inch cable between Tape in and out Activate the self test keys above the order of items tested is 1 ROM Test Tests EPROM for errors 2 RAM Test Tests SRAM for errors 3 MIDI Test Tests MIDI input output functions 4 TAPE I O Test Tests Tape input output functions 5 LED Test Lights each front panel LED for a couple seconds 6 DAC Adjust Enters DAC adjust mode press stop to exit 6 3 DAC Adjustments The only adjustment necessary in the HR 16 is the DAC adjustment This is normally done at the end of the HR 16 s internal diagnostics however holding the PATT button and p
3. ALPHA swiTCH CAP __ 91101 Por 10K TRIMPOT 0 08 0103 1 MN O 10KBSLIDEPOTMONO 009109 1 Por 10KBSLIDEPOTSTER 0 09 1010 1 f 0 fh RES __ 100 5 000010 3 R75120133 0 1 MAN GROUP DESCRIPTION PART POSITION NOTES 1K 1 8W 5 0 00 0102 R23 29 35 36 48 49 50 51 64 67 69 72 91 92 112 114 115 MAN O HR 16 HR16B Service Manual 1 00 18 RES 10K 1 8W 5976 0 00 0103 15 R5 30 32 39 52 53 82 86 97 99 103 104 106 113 121 MAIN RES 100K mews 0000104 5 Ri9252773946 SSCS MAIN 1 Res mws 9000015 MAIN 1 RES iom mews 0 00 0106 ea MAIN PSS Res 1 2K 5 0 00 0102 1 Res 15 ew 6 0 00 0160 RES 15M 1 5 0000155 1 MAIN SSCS vws 0 00 0202 4 R685679 1 oO RES 200K veW 5 000024 3 SSS RES RES RES RES RES RES RES RES RES RES RES RES RES RES RES RES RES RUB 220 18w 5 0000221 19 Ri 44244424476818385 Omn E 22K 1 8W 5 000022 3 R411223124 0 1 1 0 MAN E 18W 5 00000 2 R837 MAN E 1 8W_5 0000304 1 53M 5 0000335 1 4 E 390K 1 8 5 0000394 1
4. Ww H o HR 16 HR16B Service Manual 1 00 23 NO TRANSMITTED AS W Og N Og H In order to use the data properly it must be decoded properly into HR 16 byte format The following list gives the data locations within the unpacked decoded block of data starting with the first byte of the block being 000 NOTE absolute addresses must have an offset of 8200H added to them e g an absolute pointer to a pattern that starts at 35AH should have the pointer value 855AH 000H 0C7H 0C8H 0C9H OCBH O0CDH ODOH 1 0D2H 0D3H 0D4H 0D5H 0D7H O0D8H 0D9H 1 2 4 OESH OE6H 7 OECH F3H OF4H OFSH FDH DON T CARE MIDI channel Receive MIDI drum triggers O off Transmit MIDI drum triggers O off 1 on MIDI note assignment of CLICK 0 127 MIDI note assignment of KICK 0 127 MIDI note assignment of SNARE 0 127 MIDI note assignment of CLS HAT 0 127 MIDI note assignment of MID HAT 0 127 MIDI note assignment of OPEN HAT 0 127 MIDI note assignment of CLAPS 0 127 MIDI note assignment of PERC 3 0 127 MIDI note assignment of PERC 4 0 127 MIDI note assignment of TOM 1 0 127 MIDI note assignment of TOM 2 0 127 MIDI note assignment of TOM 3 0 127
5. 12 1 12 Lifting uie 12 7 13 Reset 12 7 14 Sram Capacitor 12 7 15 Tape 13 Y 16 RF CHOKES ide ec eger awa eee 13 7 17 AQ reset threshold sse 13 TAS AQ nieder ee epo cie pedea de 13 7 19 Volume Slider 13 7 20 PUP 14 8 0 Common 50 5 15 9 0 Service Parts egeo a dg vaso de 18 10 0 Software 20 11 0 MIDI Implementation 23 12 0 Service Manual History 31 INDEX RE 32 HR 16 HR16B Service Manual 1 00 vi 03 31 06 1 0 General Description Tape MIDI Diagram 1 provides a simplified block diagram to show major sub Pieos AD systems Note that the schematic Data sider eee reference designations and pinouts used in this manual refer to the AQ revision of both the main PCB and schematic From Keys EPROM Foot Switches 1 1 Main PC Board Revisions Mapped gt There are 3 major main PC Ad revisions A This was the initial release This board revision will require the most E extensive updating of the three CA This version of the board was a 4 layer design While offering several advantages
6. 27H TOM 4 panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 28H RIDE sound number 0 30H 29H RIDE output assign bit 7 and volume bits 0 6 0 63H 2AH RIDE panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 2BH CRASH sound number 0 30H 2CH CRASH output assign bit 7 and volume bits 0 6 0 63H 2DH CRASH panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 2EH PERC 1 sound number 0 30H 2FH PERC 1 output assign bit 7 and volume bits 0 6 0 63H 30H panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 31H PERC 2 sound number 0 30H 32H PERC 2 output assign bit 7 and volume bits 0 6 0 63H 33H 2 panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 34H PATTERN DATA 99 OFFH End of pattern Pattern data must follow these rules 1 2 Each byte of the pattern data from 34H on is either a drum event a count of clocks to wait or which indicates the end of the pattern If the event is drum event bit 7 will be 0 bits 4 6 will contain the dynamics of the note 0 7 and bits 0 3 will contain the drum to be played 0 15 in the same order as above If the event is a count of clocks bit 7 will be high and bits 0 6 will indicate the number of clocks to wait 0 126 wait 0 clocks is legal and will cause the pointer to immediately advance to the next event An empty 8 beat pattern wou
7. 63H MID HAT panning bits 5 7 0ZL 6 R amp pitch bits 0 4 0 16 15 10H OPN HAT sound number 0 30H 11H OPN HAT output assign bit 7 and volume bits 0 6 0 63H 12H OPN HAT panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 13H CLAPS sound number 0 30H 14H CLAPS output assign bit 7 and volume bits 0 6 0 63H 15H CLAPS panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 IFH 15 16H PERC 3 sound number 0 30H 17H PERC 3 output assign bit 7 and volume bits 0 6 0 63H 18H PERC 3 panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 IFH 15 19H PERC 4 sound number 0 30H 1AH PERC 4 output assign bit 7 and volume bits 0 6 0 63H 1BH 4 panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 1 15 1CH TOM 1 sound number 0 30H 1 output assign bit 7 and volume bits 0 6 0 63H 1 TOM 1 panning bits 5 7 OZL 6 amp pitch bits 0 4 0 16 15 1 TOM 2 sound number 0 30H 20H TOM 2 output assign bit 7 and volume bits 0 6 0 63H 21 2 panning bits 5 7 OZL 6 amp pitch bits 0 4 0 16 15 HR 16 HR16B Service Manual 1 00 26 22H TOM 3 sound number 0 30H 23H TOM 3 output assign bit 7 and volume bits 0 6 0 63H 24H 3 panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 25H TOM 4 sound number 0 30H 26H TOM 4 output assign bit 7 and volume bits 0 6 0 63H
8. ALESIS SERVICE CENTER SHALL BE SOLELY THE RESPONSIBILITY OF THAT ENTITY AND ALESIS SHALL HAVE NO LIABILITY TO THAT ENTITY OR TO ANY OTHER PARTY FOR ANY REPAIRS BY THAT ENTITY HR 16 HR16B Service Manual 1 00 lii 03 31 06 SAFETY SUGGESTIONS Carefully read the applicable items of the operating instructions and these safety suggestions before using this product Use extra care to follow the warnings written on the product itself and in the operating instructions Keep the operating instructions and safety suggestions for reference in the future 1 Power Source The product should only be connected to a power supply which is described either in the operating instructions or in markings on the product 2 Power Cord Protection AC power supply cords should be placed such that no one is likely to step on the cords and such that nothing will be placed on or against them 3 Grounding the Plug This product has a 3 wire grounding type of plug a plug with a grounding pin for safety purposes This plug can only be used in a grounding power outlet If the plug does not insert into the outlet you are using the outlet probably is not a grounding type of power outlet Contact your electrician to replace the obsolete outlet with a grounding type of outlet instead of defeating the safety feature of the grounding type of plug 4 Periods of Non use If the product is not used for any significant period of time the product s AC power supply cord sho
9. BUTTON This command is used to press or release the RECORD button It will affect whether the HR 16 will go into play or record when it receives a MIDI START command It does not affect what will happen when pressing play from the front panel 0000000xB released 1 pressed F7H EOX QUANTIZE AND SWING MODES This command is used to set the quantize and swing modes pH 0000xxxxB xxxx 0 9 quantize mode 0 1 4 1 1 6 221 8 321 12 421 16 521 24 621 32 TUUM 721 48 721 64 921 384 O000nnnnnB nnnnn 0 24 swing amount 0 50 F7H EOX SET PATTERN LENGTH This command is used to change the length of the current pattern OtOccccbB t O change end 1 change top ObbbaaaaB ccccbbbbaaaa 3 digit BCD length in beats c msb a Isb F7H EOX COPY PATTERN DRUM OR SONG HR 16 HR16B Service Manual 1 00 28 06H 07H 08H This command is used to copy a pattern to another pattern a drum to a pattern or a song to a song If the command is to copy a pattern the data received will be appended to the end of the currently selected pattern If the command is to copy a song the data received will be appended to the end of the currently selected song If the command is to copy a drum the drum number sent in the mode byte 1 will be copied to the drum button hit within 3 seconds of receiving this command otherwise it will be ignored 000000xxB MSB of number of unpacked bytes of data after header O
10. JAC 1 4 CLIFF MONO 4 02 0001 LCD LIT ME ME ME ME ME ME ME ME ME ME ME ME How HOW How C e C C C C C C C C C e _JAC_ _ _ ME ME ME ME 12 N 0 CITIN lt lt c icicicicicicicicicicicicicicicicicicicicicicic E N 2 2 2 2 IRlo 515 5 lt 5 5 lt co N 06 14 17 20 21 D1 5 D15 Q6 14 15 Q1 5 7 9 11 12 16 17 Q10 13 REAR PANEL OVERLAY 913 1003 1 MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN RCA ONLY HR 16 ONLY HR 16B ONLY HR 16 ONLY HR 16 ONLY HR 16B ONLY HR 16B ONLY YPD MAIN MAIN MAIN MAIN MAIN MAIN KYPD KYPD MAIN MAIN MAIN MAIN MAIN METAL PACKAGE ONLY MIS__ RUBBER STRIP 9231007 5 5 2 0 O LBS ___ 9 111006 1 o 11 KEYCAPS WHT 9111007 16 80 0 0 5 O 1541 PLS BLK 911105 16 RS 1 o 11 SLIDEPOTKNOB _ 0 2 5 0 0 0 0 o es
11. and U6 Yellow 7 19 Volume Slider Wiring Red Note that the wiring of the volume slider changed between Revisions CA and AQ Diagram 16 shows the ire a wining tor correct wiring for each board style Diagram 16 HR 16 HR16B Service Manual 1 00 13 7 20 PUP Capacitor Revision When the PUP circuit first appeared it was found that the circuit would occasionally oscillate on power up causing noise This was eliminated by adding a bypass capacitor later incorporated as C62 across the power supply pins of U20 pins 4 and 11 HR 16 HR16B Service Manual 1 00 14 8 0 Common Solutions A thorough knowledge of the software history can help solve a great many situations quickly Also be aware that with devices as full of options as the HR 16 B there are even more possibilities for user error i e the user claims that MIDI out isn t working but on checking the settings the tech finds that both MIDI clock and DRUM NOTES OUT are turned off Understanding how the user has the unit in his her setup is an important tool in troubleshooting units that act like there is nothing wrong with them While it is simply beyond the scope of this manual to present every possibility the chart below offers a majority of solutions to common situations Complaint Possible Cause Solutions O Unit is truly dead No lights or sound Blown power supply Replace and retest 5V rectifier blown D5 Note that 1N4001s Tro
12. bug which caused single step with swing on to advance in incorrect amounts If swing was advanced by while in 16th not quantize the steps would be 23 96 48 96 71 96 instead of 25 96 48 96 73 96 This is now fixed 2 Added copyright notice on power on HR 16 and HR 16 B HR 16 HR16B Service Manual 1 00 21 1 Fixed bug which caused a wrong amount of silence at the beginning of a pattern if its length was changed to a shorter value from the top and there was no drum event on the old or new downbeat For example if no events existed on beats 1 and 2 and the length from top was changed to be shorter by one beat the amount of silence before the first event would be wrong 2 Fixed bug which caused sysex loading to be garbled if any real time MIDI information was received during the sysex dump This seemed to only be a problem with IBM MPU 401 interfaces 3 All individual s names have been removed from the software HR 16 HR16B Service Manual 1 00 22 11 0 MIDI Implementation ALESIS HR 16 HR 16B MIDI SYSTEM EXCLUSIVE FORMAT The following information is provided as a guide for programmers wishing to modify the data received via MIDI from the HR 16 for the purpose of interchanging patterns from separate block dumps modification of drum setups MIDI channel assignments etc Great care must be taken to insure that all modified addresses are valid since one incorrect value the length of a pattern for example could result in all dat
13. current limiting resistors These have resulted in a few unique situations that may need to be dealt with see section 7 16 for details HR 16 HR16B Service Manual 1 00 1 2 1 Battery Backup Battery backup is actually more complicated than it might first appear as it depends a good system reset see section 3 1 for details in order to function properly The actual backup circuit consists of a battery 3V 3 6V Lithium a 10K resistor R97 for checking standby current see below steering diode D7 a filter capacitor C59 and a transistor resistor diode combination that acts as a steering diode This combination may be missing on older board revisions and must be installed see _ section 7 1 to prevent data corruption due to a 12 22 87 significant difference between and the amplitude REV A of the data buss SRAM standby current should always be checked While the unit is off check the voltage across R97 the voltage is higher than 80mV specification although a 1 to 20mV range is more normal then a problem exists Usually it indicates a bad or simply wrong SRAM or a short somewhere along the MEM PWR line Note that for a short time i f Sony 58256 PM high power SRAMs were being installed at the factory causing batteries to drain in about 1 year They should be replaced with low REV CA power versions 58256 LP when found in order to eliminate excess battery drain We are currently using Hit
14. data must follow directly after pattern 00 s data etc 4 Locations 2CDH 2CEH start of free memory and 2DIH 2D2H length of free memory must be kept valid 5 Song 99 MUST exist This means that at least an empty song 03H 00H FFH must be at the end of memory and song 99 must point to it 6 It is suggested that all DON T CARE data be left in the state that it is received in although these locations can be replaced with zeroes PATTERN DATA FORMAT The following is the format of each pattern starting with the address pointed to byte the absolute pointer to the pattern offset by 8200H 00H LSB of number of bytes in pattern including header 01H MSB of number of bytes in pattern including header 02H LSB of number of beats in pattern in BCD format 0 beats 03H MSB of number of beats in pattern in BCD format empty pattern 04H KICK sound number 0 30H 05H KICK output assign bit 7 and volume bits 0 6 0 63H 06H KICK panning bits 5 7 OZL 6 amp pitch bits 0 4 0 16 15 07H SNARE sound number 0 30H 08H SNARE output assign bit 7 and volume bits 0 6 0 63H 09H SNARE panning bits 5 7 OZL 6 R amp pitch bits 0 4 0 16 15 OAH CLS HAT sound number 0 30H OBH CLS HAT output assign bit 7 and volume bits 0 6 0 63H OCH CLS HAT panning bits 5 7 0 L 6 R amp pitch bits 0 4 0 16 IFHz15 MID HAT sound number 0 30H OEH MID HAT output assign bit 7 and volume bits 0 6 0
15. decks are created equal Probably the largest factor involved is the decks input and output capacitances These can greatly affect the signals sent to and from the deck and may cause some decks to be incompatible with the tape I O needs of the HR 16 However these cases should be rare as the components chosen for the HR 16 are based on the industry standards that most manufacturers adhere to While we have heard many complaints regarding tape back up we have actually found very few actual tape failures Most of the complaints arise from user error so below is a list of successful backup and tape sync strategies 1 When attempting to save to a stereo cassette deck use only the 1 channel using both channels may result in odd phase cancellations during playback 2 Avoid using any noise reduction systems i e Dolby or DBX as these can distort the timing of the pulse train that contains the data HR 16 HR16B Service Manual 1 00 6 3 Avoid using adapters for two reasons 1 Some adapters contain built in attenuators that can result in extremely reduced levels both to and from the tape 2 Oxidation and wear and tear can cause adapters to become intermittent 4 Always make several copies of each save It s especially smart to make copies on at least 2 different tapes as well This reduces the chances that tape dropouts will cause loss of data 5 Always use normal bias tapes as high bias tapes actually end up recording noise whic
16. disk or film WIMA type of capacitor This replacement is recommended regardless of whether the capacitor seems to be failing or not 7 14 Sram Capacitor e Revision A The blue monolithic block RAM capacitors used throughout the board were found to be unreliable when used in timing critical applications due to excess leakage current In this case the capacitor causes excess battery drain and is the primary cause of battery failure These capacitors should be replaced with either a ceramic disk or film WIMA type of capacitor regardless of whether the capacitor seems to be failing or not HR 16 HR16B Service Manual 1 00 12 7 15 Tape Capacitors e Revision amp CA The blue monolithic block RAM capacitors used throughout the board were found to be unreliable when used in timing critical applications due to excess leakage current Here the capacitors reside in the tape input path C11 and C23 and may cause the distortion of incoming tape signals Such distortions can cause the loss of tape loading capabilities These capacitors should be replaced with either a ceramic disk or film WIMA type of capacitor if tape loading failures occur 7 16 RF chokes Revision CA amp AQ Occasionally the R F chokes on these board revisions located near the power input jacks will bust a lead during shipping When this occurs it may not be possible to repair the choke In this case it is O K to remove the choke and add jumpers across its old lo
17. first step of the song 2 Fixes test routine display to read HR 16 instead of MMT 8 1 Fixes cassette output bug that would occasionally cause a pattern to output data much longer than it should which would make the cassette interface unusable 1 Fixes cassette input bug that would cause data to be corrupted if only pattern 99 is loaded in from tape 2 Fixes bug that would not recall the voice settings of a pattern after it had been loaded from tape loading one pattern only Previously the pattern would have to be reselected after loading it from tape before the voices would recall their proper settings 1 Fixes cassette input bug that would cause pattern 99 to be erased if a single pattern or song was loaded in or a cassette was verified 1 Fixes bug that when adding beats to the beginning of a pattern any drums more than one that occurred on beat 1 would remain on beat 1 instead of moving past the inserted beats 2 Fixes bug that would cause an incorrect display if aborting LOAD ONE PART before tape data has begun when previously in song mode and aborting LOAD ONE SONG before tape data has begun when previously in part mode 3 Increased delay loops in display routines so that fewer LCD displays would be rejected in production 4 Added feature that allows MIDI program selection of patterns to work while a part is playing If a new program number is received over MIDI this program number will be selected to be the NEXT pa
18. is highly recommended and is absolutely necessary if a 58257 SRAM is in the unit sensitive to supply voltage the older lt SRAMs 7 2 Glass Zener 015 e e Revisions amp CA 257s are much more 256 This is because For a short time glass package 1N5231B zener diodes were used instead of the more familiar metal package These were found to be unreliable and should be replaced with metal package zeners 7 3 Dirty Cliff jacks All Revisions Oxidation builds on The contacts here Use a small scraping tool to clean the contacts Diagram 9 7 4 Ground CE All Revisions It was discovered that many units returned for odd crashes all appeared to have a common component National EPROMs After further investigation it was revealed that it was not due Solder Side SRAM gt 20 o on IO O 2 Diagram 11 HR 16 HR16B Service Manual 1 00 Occasionally oxidation will build up on the cliff jack contacts causing the jack normaling to fail When this happens some drum sounds will be lost when using the unit in mono Only one cable plugged in The solution is to thoroughly clean the normaling contacts See diagram 9 for location Revision Pin 22 Revision AQ only Diagram 10 to defective components but due to a minor incompatibility It was determined that using CE pin 20 to enable the device took too long and the 8031 would occasionally atte
19. matrix is pulled low one at a time via U14 which is memory mapped If any button along the row is pressed the corresponding column input U22 will appear high If J13 pin buttons are pressed all Kick Claps Snare Open Close 6 column inputs will appear as a low D9 Tm Kids 015 42 47 provide protection for the outputs 014 Use i gt diagram 3 to localize individual button failures 7 vi 3 4 MIDI I O E T The MIDI hardware is a standard implementation MIDI out begins at the 8031 s TXD port pin 11 and travels via R6 J13 pin to the darlington pair U22 pin 7 Q1 Q2 Note that the 8031 s internal pullup is not very strong and older units revision A may require the addition of an external pullup resistor for the MIDI out to function correctly see section 7 7 MIDI in consists mostly of the opto isolator U4 protection diode D6 pullup R7 and threshold resistor R5 Note that the threshold resistor may need to be changed in order to eliminate false MIDI triggers see section 7 6 Diagram 3 HR 16 HR16B Service Manual 1 00 4 4 0 DM3AG ASIC The DM3AG ASIC is a complex LSI device specifically designed for the purpose of playing percussion samples Obviously the internal workings of such a device are beyond the scope
20. of this manual However a brief description of some of the important pins follows NAME PIN s Function CLOCK 37 Asic Clock Input 6MHz in HR 16 DACO DAC16 42 51 53 60 Output to DAC A0 A19 3 17 19 23 Mask Address Buss 07 61 68 Mask Rom Data SNHO 39 Output Sample and Hold Control SNH1 40 i SNHIN 41 Output Sample and Hold Inhibit STRES 26 Instruction reset strobe STB 25 Instruction latch strobe 61 63 65 67 1 d 5 7 9 D3 D2 DI AO A2 NA 60 62 64 66 68 2 4 6 8 11 10 17 05 D A5 58 59 13 12 DACIS5DAC o 07 GND Al 19 9 56 57 15 14 DM3AG ASIC is ASIC 52 53 Socket GND Top GND DAC 1 20 View 50 51 2 DAC2 DAC9 BOTTOM Al7 Al5 48 49 23 22 DAC3 DAC8 VI EW 8 16 46 47 25 24 DACA DAC7 STB TST 44 45 42 40 38 36 34 32 30 28 26 DAC5 DAC6 DACO SNH1 RST VCC MD7 MD5 MDI STRES 43 41 39 37 35 33 31 29 27 SNHIN SNHO CLOCK GND MD6 MD4 MD2 MDO 4 1 Mask ROMs Diagram 5 The mask ROMs contain the all of the sample information The 18 bit address buss allows for 2 megabytes per mask ROM Address line A19 from the ASIC is actually used in conjunction with Q15 to switch the Mas
21. over the older DM3AG ou 1 mAN e version improved R F 7 characteristics smaller size etc it 16B was found to be extremely difficult to Block T service internal shorts can only be Diagram Hilos repaired using lifted pins and UNI jumpers l AQ This was the final revision This rada revision will of course need the Diagram 1 fewest updates and should be relatively easy to troubleshoot Diagram 2 is provided in order to assist with board revision identification 2 0 Power Supply The power supply begins with the 9 Volt A C adapter Alesis P2 mini plug or P3 barrel types Input from J1 is R F filtered before on off switch S1 From there it is split for the 12V 12V and 5V rails The 12V rail consists of a voltage doubler and D2 D3 a 7812 regulator 08 and a filter capacitor The 12V rail is a mirror of the 12 rail consisting of voltage doubler C2 C4 and D1 D4 a 7912 regulator 09 and a filter capacitor C7 The 5 rail consists of a rectifier diode D5 a filter capacitor C5 a 7805 regulator U10 and a multitude of 0 1uF bypass capacitors Note that the raw 10V line used by the microprocessor reset and the SRAM power supply when retrofitted is located at the input to the 7805 regulator Note that revision AQ the latest boards also incorporate several R F suppression chokes and
22. the battery backup will work R28 R29 and the 5 1V zener diode D15 work together as a voltage divider to the base of Q4 and is designed so that transistor Q4 will turn on when the raw 10V supply is roughly 7V This is to ensure that RESET does not occur until after the 5V regulator is fully functioning i e 5V rail is solid If RESET occurs too early noise on the 5 rail can cause data corruption Before the Q4 turn on threshold Q5 remains turned on the base of the transistor being pulled up by R30 This in turn holds the voltage across C20 at 3 volts This is below the threshold set by R25 and R96 necessary to turn on the comparator U1 pins 10 11 and 13 leaving the reset line high pulled up by R10 Once the raw supply has reached a sufficient level to turn on Q4 roughly 7V Q4 will pull the base of Q5 low turning it off This allows C20 to begin charging through R24 Once C20 has charged to roughly 2 5V the comparator will switch states and hold it low due to the hysteresis established by R27 This completes the reset cycle during power up During power down the opposite occurs ensuring that the 8031 is held in a reset state during power down as well This is necessary in order to prevent random data from being written into the SRAM during shutdown Be aware that this can cause unusual unit lockups to occur if the circumstances are just right For example if an HR 16 was shut off while in record mode it s possible the 803
23. to install the HR 16A B EPROM into their new HR 16B WRONG This EPROM is intended to be used only in the HR 16 and does not have the correct MASK ROM addressing tables to play HR 16B sounds Faulty DM3AG ASIC Replace and retest Faulty power supply rail Troubleshoot and repair as necessary Faulty PUP circuit one rail not making it to the Troubleshoot and repair as necessary op amp Volume slider only works for 1 2 of it s range Slider wiring incorrect for particular main PC See section 7 19 Board revision All Trademarks are property of their respective companies HR 16 HR16B Service Manual 1 00 17 9 0 Service Parts List GROUP DESCRIPTION Pante QTY 3 3 Nots PCB D1 MAIN REVAQ 820008 PcB DrKEYPAD 8200040 1 _ OOOO J SS 820009 1 SSS asy casETOPASSvb2 820000 1 SSS J T S i4PNDL7 5 PINSIES gt 1 cap 01 MFDCERDISC 1 02 0104 28 11235051567173437380 20 MFbELEC 082200 SSC cap 330 MFDELEC 1 109033 3 SSS cap 470 MFDELEC 109047 64 7 1 320475 7 669228488 O O MAIN SSS cen 100 1020100 MAIN SSS 150 PFD CEADISC 1
24. 02051 11 tri843082394 MAN SSCS cen 27 PFDCERDISC 1020270 2 SSS ipno 4140014 5 31214 ONKPDPGB T s PINSILHDR 415005 SSC CCS AN 1200102 7 16313748495758 SSCS FIL T o0 MFDFILM 1200109 4 694506062 MAN MFD FILM 120014 eras 2200 1200222 e 30313441424446 SSCS Fit 0 022 MFD FILM 1200222 4 62929 MFD Fit 1200473 How esx PPBLK 5000003 1 TOz20REG SSS How 1 500009 4 How 32ax8 PPHiLO 5000013 4 SY HOW 4 24x5 16 PPB PLAST 5001002 18 caser LL SSS 5002001 4 Sd CCS How 6 INTSTARWASHER 5016002 1 T T HOW MAN HOW HOW MAIN MAIN MAIN MAIN MAIN MAIN MAIN MAIN NATIONAL ONLY NATIONAL ONLY NATIONAL ONLY 7 IC IC IC IC IC IC IC IC IC IC IC IC IC IC
25. 1 was put into reset in the middle of writing a two byte pointer into memory If only one of those bytes is written before reset then it may point to an incorrect location in memory battery backup holds the incorrect data When the unit is powered back up the incorrect pointer may send the software into never never land where the only way to recover is to reinitialize the unit HR 16 HR16B Service Manual 1 00 3 3 2 Memory Mapped In order to easily control the vast number of hardware functions that the 8031 needs to access a system of memory mapped I O is used The basic idea is to make hardware functions appear to the 8031 as unused memory locations That way all that the software has to do is write to a memory location in order to send that information to a specific device such as the LCD or ASIC 74HC138 U13 performs the majority of the work in this circuit Two things are required before U13 becomes active 1 A15 must be low i e the 8031 is accessing the lower 32K of address space 2 The 8031 White line must be active the 8031 is performing a memory write A15 is used to directly control which function memory or I O is active Once U13 is enabled addresses A8 A10 are decoded by it and the latch corresponding to the value of the decoded address is strobed At this point data on the 8031 data buss is written into the latch 3 3 Keypad I O Keypad I O is handled through a simple polling process Each row of the keypad
26. HR 16 HR 16B Drum Machines Service Manual V1 00 7 27 95 HR 16 HR16B Service Manual 1 00 i 03 31 06 PREFACE This document is intended to assist the service technician in the operation maintenance and repair of the HR 16 and HR 16B Drum Machines Together with the HR 16 B Reference Manual this document provides a complete description of the functionality and serviceability of these machines Any comments or suggestions you may have pertaining to the document are welcome and encouraged READ THIS In addition to any purchase price that Alesis may charge as consideration for Alesis selling or otherwise transferring this service manual Manual to you if you are not a service and repair facility Service Center authorized by Alesis in writing to be an authorized Service Center Alesis sells or transfers the Manual to you on the following terms and conditions Only Service Centers authorized by Alesis in writing are authorized to perform service and repairs covered by an Alesis warranty if any and transfer of the Manual to you does not authorize you to be an authorized Service Center Therefore if you perform or if the Manual is used to perform any service or repairs on any Alesis product or part thereof any and all warranties of Alesis as to that product and any service contract with Alesis for that product shall be voided and shall no longer apply for such product even if your services or repairs were done in accordance with the M
27. LSI 5 M Manual voice tune mix 24 25 Mask Rom 5 17 18 mask ROMs 5 MDO MD7 5 MEM PWR 2 MEMORY DUMP 23 29 memory mapped 3 4 microprocessor 1 MIDI 3 4 8 11 15 16 20 21 22 23 24 28 29 30 mono 10 18 monolithic block ram capacitors 12 13 Most Significant Bit 6 23 N noise 2 3 7 8 11 12 18 14 normaling 10 10 op amp 3 16 17 opto isolator 4 11 oscillation 3 Output Sample and Hold 5 output section 6 Oxidation 7 10 oxidize 12 P PATTERN DATA 26 27 30 PCM 54 6 8 12 16 17 piezo 3 6 16 18 power supply 1 13 14 15 17 program 3 20 24 program change 21 pullup resistor 4 7 16 2 14 17 Q Q1 Q2 4 Q10 2 18 Q11 2 012 013 3 Q3 6 Q4 3 Q5 3 QUANTIZE 21 22 28 29 R R F 1 10 11 18 R F suppression 1 R10 3 R100 3 19 R105 3 R110 10 8133 13 R16 R20 6 R22 6 19 R23 6 19 R24 3 12 19 R25 3 R27 3 R28 3 13 16 19 R29 3 R30 3 R41 12 19 R5 4 11 16 19 R52 6 R53 6 R54 6 19 R6 4 11 19 R60 12 R63 6 19 R68 6 R7 4 11 19 R73 R75 6 R90 6 8 18 R96 3 R97 2 R99 3 RAM Test 8 raw 10V 1 3 read 3 6 10 20 reinitializing 8 reset 1 2 3 12 13 15 16 ribbon cable 16 ROM Test 8 RXD 3 S 51 1 samples 5 self test 8 shield 11 shorts 1 11 SHUFFLE 21 25 SIP 6 19 SNHO 5 SNH1 5 SNHIN 5 software histo
28. MIDI note assignment of TOM 4 0 127 MIDI note assignment of RIDE 0 127 MIDI note assignment of CRASH 0 127 MIDI note assignment of PERC 1 0 127 MIDI note assignment of PERC 2 0 127 MIDI echo 0 0 1 on MIDI program select O off 1 on Clock mode O MIDI amp internal 1 internal only 2 tape MIDI clock out O off 1 on Auto start O off 1 on Click value Click in play O off 1 on Manual voice tune mix O off 1 on Pad dynamics 0 0AH Song loop O off 1 on Sysex enable 0 off 1 on Software version 5 ascii bytes starting with a space 20H if an HR 16 or a B 42H if an HR 16B followed by a 4 digit version number e g 2 00 or 32H 2EH 30H 30H DON T CARE 0 DON T CARE HR 16 HR16B Service Manual 1 00 24 OFEH OFFH 100H 187H 188H 191H 192H 1A1H 1A2H 1FFH 200H 201H 202H 203H 204H 205H 2C6H 2C7H 2C8H 2CCH 2CDH 2CEH 2CFH 2D0H 2D1H 2D2H 2D3H 2D4H 2D5H 2D6H 2D7H 2D8H 2D9H 2DAH 2DBH 2FFH 300H 301H 302H 303H 304H 305H 306H 307H 3C8H 3C9H 3CAH 3CCH 3CDH 3D2H 3D3H 3D6H 3D7H 3FFH 400H 27H OB5H DON T ALTER this can be DON T CARE if manual voice tune mix is off DON T CARE 0 DON T CARE MSB of absolute pointer to pattern 00 LSB of absolute pointer to pattern 00 MSB of absolute pointer to pattern 01 LSB of absolute pointer to pattern O1 MSB of absolute pointer to pattern 02 LSB of absolute pointer to pattern 02 MSB of absolute p
29. PROM or SRAM Faulty DM3AG ASIC Pulling down the 8031 data buss Faulty I O latch pulling down lines on data buss Other faulty reset component Open or short in 8031 data buss Open or short in 8031 address buss Troubleshoot and repair as necessary see section 3 X Faulty LCD pulling down lines on data buss Test with new LCD Faulty LCD Test with new LCD Faulty LCD cable Replace and retest Faulty 74HC138 U13 or open between U13 Troubleshoot and repair as necessary and LCD header Troubleshoot and repair as necessary section 3 2 Troubleshoot and repair as necessary section 3 1 Troubleshoot and repair as necessary see section 3 X see see C 20 leaking excessively Troubleshoot and repair as necessary see section 7 13 Faulty 8031 EPROM or SRAM Troubleshoot and repair as necessary see section 3 X D15 is glass package type Revision A or CA Replace with metal package type see section only 7 2 R116 is pulling 8031 V too low revision AQ Add jumper across resistor only Complaint Possible Cause Solutions ________ HR 16 HR16B Service Manual 1 00 15 Intermittent reset cont R28 reset threshold is wrong value Revision Add another 3K resistor in parallel see section AQ only 7 17 Other faulty component is 8031 reset circuit Troubleshoot and repair as necessary No sound at all Faulty DM3AG ASIC PCM 54 DAC 4052 Troubleshoot and repair as n
30. a being lost in the HR 16 These errors may not show up immediately since the incorrect values may not be accessed by the HR 16 until a particular pattern or song is selected Therefore it is recommended that any data manipulation programs be thoroughly tested after loading into the HR 16 by selecting and recording on many patterns and songs before assuming that the data is valid For any of the sysex commands to be transmitted or received the SYSEX ENABLE function MIDI UTIL page 15 must be turned on 11 possible commands will be transmitted in the following format HEX COMMENTS FOH SYSTEM EXCLUSIVE STATUS BYTE 00H 00H OEH ALESIS I D NUMBER 01H HR 16 IL D NUMBER 00H 0AH SYSEX COMMAND dis DATA F7H EOX The following sysex commands are transmitted and received by the HR 16 00H COMPLETE MEMORY DUMP A system exclusive MIDI data dump from the HR 16 is initiated by holding the TAPE button down pressing and releasing the left arrow button once and then pressing the RECORD button This command is followed by a block of data representing the contents of the HR 16 s memory In order to optimize the data transfer 8 MIDI bytes are used to transmit each block of 7 HR 16 data bytes If the 7 data bytes are looked at as one 56 bit word the format for transmission is eight 7 bit words beginning with the most significant bit of the first byte as follows SEVEN HR 16 BYTES
31. achi 62256ALPs as replacements CAUTION panger of explosion if battery is incorrectly replaced Replace only with the same type or equivalent type recommended by the equipment manufacturer Battery Manufacturer Tadiran Type TL 5101 Rating 3 6V 2 2 PUP Circuit The PUP quiet Power UP circuit is designed to prevent the unit from making noise during power up Note that this circuit will not be present on the REV AQ earliest main PC boards The circuit utilizes the Diagram 2 RESET line section 3 1 to control the power supply lines to U20 which is the final active stage before the output jacks Since both rails operate similarly we ll only take the time to explain the operation of the rail During power up the RESET line is held low until the regulators are fully functioning At this point Q11 is turned off by RESET via R104 This has the affect of turning off Q10 by allowing the base of Q10 to pull high via R101 As soon as the reset line goes low Q11 will turn on pulling the base of Q10 lower Q10 is now biased into saturation allowing roughly 12V to be fed to the op amps C65 is provided for extra filtering The rail consists of R99 R100 R105 Q12 Q13 and C64 HR 16 HR16B Service Manual 1 00 2 C62 was added to the analog rails of the op amp to prevent oscillation during power up and may need to be added to some older units see section 7 20 3 0 The 8031 The 8031 MPU is th
32. anas pecie cu de d ae 2 3x0 T h 80981 ea ee TER d ae 3 3 1 ae Ais as e ce 3 3 2 Memory Mapped l O sse 4 3 3 Keypad cue petere ig eu de da 4 4 4 0 les 5 41 Mask ROMS o ecu 5 5 0 Analog Signal 6 5 1 Drum Signal Output sees 6 5 2 Piezo Data Slider 6 5 3 VO 6 5 4 Tape ed ck dece e i aie 7 5 5 Tape oei iaa e nas 7 6 0 Test Procedures iiia Saves nad es 7 6 1 General Testing sse 8 6 2 Internal Diagnostics and Hidden Keys 8 6 3 DAC Adjustments sse 8 7 0 Updates and Corrections 9 7 1 New SRAM Supply 9 7 2 Glass Zener 015 9 73 Dirty aie eere 10 A Ground 10 RE aire cur inna vs 10 7 6 10K MIDI Resistor R5 sese 11 MIDIPull p aaia 11 1 8 pa sep 11 7 9 LCD Contrast 5 11 FAO DAG 2c iode aie ieee 12 7 11 Old Keypad PC
33. anged the percentage display relationship to the clock The original shuffle values and new values are shown below QUANT OLD SHUFFLE NEW SHUFFLE 1 4 0 5096 0 5096 1 6 0 16 5096 7596 0 24 50 68 8 1 8 0 12 5096 7596 0 16 50 66 7 1 12 0 8 5090 7590 0 12 50 68 8 1 16 0 6 5096 7590 0 8 50 66 7 1 24 0 4 5096 7590 0 6 50 68 8 1 32 0 3 5090 7590 0 4 50 66 7 1 48 0 1 50 62 5 0 2 50 62 5 1 64 0 5096 0 1 50 58 3 OFF 0 5096 0 5096 Despite the displayed percentage being smaller in the new values there are actually more shuffle steps than before The old displayed percentages represented the ratio between the clock location of the shuffled beat and the clock location half way between two un shuffled beats The new percentage represents the percentage of the total time of two occurring beats that the first of a shuffled pair will take For example 1 16 notes set to shuffle 8 shifting every other 16th note 8 clocks late will result in the first 16th note getting 32 clocks and the second 16th note getting 16 clocks instead of 24 each when shuffle 0 This results in the first 16th note getting 66 7 of the total time of both 16th notes 32 48 66 7 which is equivalent to 16th note triplets This percentage representation is more useful than the old percentage HR 16 and HR 16 B 1 Fixes lots o bugs 2 Add lots o features HR 16 B only 1 Changed JAM BLOCK name to BLOCK HR 16 and HR 16 B 1 Fixed
34. anual All service or repairs done by you or with reference to the Manual shall be solely your responsibility and Alesis shall have no liability for any such repairs or service work All such service or repairs are performed at the sole risk of the person performing the service or repairs You agree that all such work will be performed in a competent professional and safe manner at all times and to indemnify and fully hold Alesis and its successors and assigns harmless in the event of any failure to so perform Your purchase of the Manual shall be for your own ultimate use and shall not be for purposes of resale or other transfer As the owner of the copyright to the Manual Alesis does not give you the right to copy the Manual and you agree not to copy the Manual without the written authorization of Alesis Alesis has no obligation to provide to you any correction of or supplement to the Manual or any new or superseding version thereof Alesis shall have the right to refuse to sell or otherwise transfer repair parts or materials to you in its sole discretion You shall not use sell or otherwise transfer spare or replacement parts supplied by Alesis to you i to repair or be used in products manufactured for or by third parties or ii to any third parties for any purpose You shall not make any warranties or guarantees with respect to the products of Alesis or the use thereof on behalf of Alesis or in your own name The foregoing descri
35. bes the entire understanding related to sale or transfer of the Manual to you and no other terms shall apply unless in a writing signed by an authorized representative of Alesis HR 16 HR16B Service Manual 1 00 03 31 06 WARNINGS TO REDUCE THE RISK OF ELECTRIC SHOCK OR FIRE DO NOT EXPOSE THIS PRODUCT TO WATER OR MOISTURE CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN The arrowhead symbol on a lightning flash inside a triangle is intended to alert the user to the presence of un insulated dangerous voltage within the enclosed product which may be of sufficient magnitude to constitute a risk of electric shock to persons The exclamation point inside a triangle is intended to alert the user to the presence of important operating maintenance and servicing instructions in the literature which accompanies the product CAUTION Danger of explosion if battery is incorrectly replaced Replace only with the same type or equivalent type recommended by the equipment manufacturer Battery Manufacturer Tadiran Type TL 5101 Rating 3 6V REPAIR BY ANY PERSON OR ENTITY OTHER THAN AN AUTHORIZED ALESIS SERVICE CENTER WILL VOID THE ALESIS WARRANTY PROVISION OF THIS MANUAL DOES NOT AUTHORIZE THE RECIPIENT TO COMPETE WITH ANY ALESIS DISTRIBUTOR OR AUTHORIZED REPAIR SERVICE CENTER IN THE PROVISION OF REPAIR SERVICES OR TO BE OR MAKE REPAIRS AS AN AUTHORIZED SERVICE CENTER ALL REPAIRS DONE BY ANY ENTITY OTHER THAN AN AUTHORIZED
36. cation In most cases this shouldn t be necessary as the units should have had their chokes hot glued to the board at the factory Any units that have loose chokes need to be glued hot glue recommended to prevent future damage 7 17 AQ reset threshold Revision AQ During the development of the AQ main PC board Volume slider wiring for of the prime considerations was to reduce R F Revisions A amp AC emissions to virtually Towards this end a 100 ohm resistor R133 was introduced between the raw supply Yellow Black voltage and the rest of the circuitry to reduce power supply noise This had the effect of increasing the threshold of the RESET circuit and was found to cause some units to reset repeatedly in low power situations i e use of lots of lights in a club could cause fluctuation in the local power by 15V to 20V causing the unit to reset over and over again R28 is part of the threshold circuit for the RESET line Originally valued at 3K the new value is 1 5K easily obtained by adding an additional 3K in parallel This will bring the threshold into a more reasonable range Orange Brown 7 18 AQ R116 e Revision AQ LA Again an attempt to reduce power supply noise this Black resistor was found to sometimes reduce the power supply level to the 8031 and surrounding circuitry to below the required 4 75V It is recommended that a jumper be soldered across this resistor located between the 8031
37. ceiving a step to next drum command when currently on the last drum of a beat the command will be ignored 000000xxB O enter step mode step mode 2 step to next beat 3 step to next drum F7H EOX REQUEST SYSEX DUMP This command is used to request a complete sysex memory dump from the HR 16 After receiving this command if not in PLAY mode the HR 16 will send out its complete memory via MIDI F7H EOX CHANGE VOICE TUNE MIX SETTINGS This command is receive only and is used to change the voice settings of the current pattern It can function while the pattern is playing and will update the display if the settings being displayed are HR 16 HR16B Service Manual 1 00 29 changed It will be ignored if in song mode The format is packed as 8 MIDI bytes per 7 data bytes as described in the MIDI bulk dump explanation The data is identical to bytes 4 through 33H in the pattern data format data 48 data bytes transmitted as 55 MIDI bytes F7H EOX 09H MIDI COMMUNICATIONS TEST This command is used to insure that bi directional MIDI communication is functioning If an HR 16 receives the inquiry command FOH 00H OEH 01H 09H 00H F7H it will respond with the response command FOH 00H OEH 01H 09H 01H F7H only if MIDI ECHO is turned off If MIDI ECHO is on the transmitting device will see the inquiry message returned to it if bi directional communication is functioning This function is useful in dete
38. djustments All Revisions Normally the LCD contrast is adjusted at the factory However in the event an older LCD is replaced or the contrast is not enough to suit the user it may be necessary to change the hardware to achieve a suitable contrast level Diagram 14A shows the changes needed to convert older revisions so that the trimpot N cunosce Will function in a more appropriate range Diagram 148 shows the i latest configuration used on older revisions to achieve a nominal contrast level In revision AQ boards the only way to change A lo contrast is by adding or removing if one is present a jumper 2 b across 021 located by J12 e Diagram 14 HR 16 HR16B Service Manual 1 00 11 7 10 DAC Drift Revisions Was It has been found that some PCM 54 s linearity tend to drift with time and temperature In order to improve the linearity 1 leg of R60 one leg of C47 and pin 27 of the PCM 54 should be lifted and soldered together see diagram 15 This should only be necessary if the user complains of noise after the unit warms up ls now R60 IMQ L Socket C47 0 01 uF PCM54HP R60 IMQ 7 11 Old Keypad PC Boards Revision The original HR 16 came with standard PCB type contacts tinned copper traces but these were found to over time This was especially evident when the unit was used in a moisture rich en
39. e heart of the HR 16 s control section It handles everything from keypad input and MIDI I O to sequencing Note that the 8031 data buss serves a dual purpose This buss multiplexes between low order addresses 1st 8 bits and data Latch U7 is used to hold the low order address half during 8031 read and write cycles The EPROM 011 is used to hold 8031 program information The SRAM U12 holds system variables as well as user sequence data Z1 provides the 12MHz 8031 clock MIDI I O is handled through the 8031 s built in RXD Read Serial Data and TXD Transmit Serial Data ports Tape I O and piezo input is handled through the built in 8031 I O ports DM3AG ASIC control and LCD output are handled through memory mapped see section 3 2 Keypad decoding uses both forms of I O see section 3 3 3 1 Reset The 8031 reset circuit is perhaps the single most important circuit in the HR 16 When this circuit is functioning incorrectly problems ranging from loss of battery backup to a complete lock up of the machine can occur A thorough knowledge of the operation of this circuit will greatly facilitate troubleshooting this unit This circuit uses the differential between raw 10V and regulated 5 to generate the required signals for system RESET This is necessary due to fact that the system MUST be in a reset state while powering down otherwise random noise on the 8031 data and address busses could corrupt SRAM data and destroy any hope that
40. ecessary analog switch or op amp Faulty volume slider Test AUX outs Repair as necessary User error i e drum pads set to wrong Check operating parameters outputs volumes set to etc No sound from a particular drum User error ie drum pads set to wrong Check operating parameters Adjust them as outputs volumes set to This is necessary particularly noticeable on drums that panned hard left or right TOM 1 and TOM 3 of the default drum kit Dirty or broken cliff 1 4 jack This is Troubleshoot and repair as necessary see particularly noticeable on drums that panned section 7 3 hard left or right TOM 1 and TOM 3 of the default drum kit Faulty Analog switch Troubleshoot and repair as necessary Faulty op amp U20 U21 or component in Troubleshoot and repair as necessary surrounding circuitry Component failure in keypad circuitry This is Troubleshoot and repair as necessary see actually fairly rare but it can happen section 3 3 Intermittent buttons Old keypad PC Board Replace with new style keypad PC board and retest Dirty rubber keypad Clean keypad contacts with non residue cleaner such as Blue Shower Replace and retest No or intermittent MIDI out fares rera No or intermittent MIDI in ee ee 0 No tape out No tape in Broken 1 8 jack J5 Faulty comparator U1 Data slider not working at all board Fau
41. ery drain 2 12 binary weighted resistor network 6 16 button failures 4 buzz 8 bypass 1 14 15 16 C1 1 18 C11 13 16 18 C16 6 18 C2 1 C20 3 12 C23 18 16 INDEX C3 1 C34 6 18 CA 1 18 C47 12 C5 1 15 18 C50 6 C59 2 C6 1 18 C62 3 14 C64 3 C65 3 C7 1 CA 1 9 10 11 12 13 14 15 cassette 6 20 CE 5 10 16 ceramic disk 12 13 15 chokes 13 Click value 24 cliff jack 10 CLOCK 3 5 10 15 21 24 25 comparators 6 contacts 10 12 16 COPY 29 30 crashes 10 16 17 D D1 1 18 D15 3 4 15 18 D19 6 D2 1 18 D21 11 D3 1 D4 1 D5 1 15 D6 4 18 D7 2 5 D8 9 DAC 5 6 8 11 16 17 18 21 DACO DAC16 5 data buss 2 3 4 5 10 15 16 17 data corruption 2 3 9 data slider 6 16 17 DataDisk 7 distortion 13 DM3AQG 3 5 6 15 16 17 drift 12 dropouts 7 E EPROM 3 8 10 15 16 17 H hot glue 13 HR 16 3 5 6 7 8 11 12 15 17 18 20 21 22 23 24 28 29 30 HR 16B 17 18 23 24 1 I O 3 4 6 8 15 17 HR 16 HR16B Service Manual 1 00 32 Instruction latch strobe 5 Instruction reset strobe 5 internal diagnostics 8 J J1 1 18 J11 6 18 J12 11 18 J5 16 18 J6 16 jitter 6 jumper 10 11 13 15 K keypad 3 4 6 12 16 18 19 20 L LCD 3 4 11 15 18 20 LED Test 8 Lithium 2 18 lock up 3 low order address 3 low power 2 13
42. h could make it past the wave shaping circuitry and cause false triggers 6 Always verify tapes after saving them This helps reduce the chances of bad saves Note however that the HR 16 does not compare the tape to the contents of memory It simply verifies that the information on the tape is valid HR 16 data 7 Experimentation with record and playback levels usually lead to better results Trouble shooting tape problems should begin with listening to the data tape audibly This can help the technician determine if the problem occurs during tape save or load If unusual dropouts are heard then the problem is either just a bad tape bad cable or the tape save circuit Normal sounding tapes usually indicate a tape load problem Only practice will help you determine what is normal 5 4 Tape Output The tape output hardware is simply the 8031 output port P3 2 pin 12 a pullup resistor R40 and a voltage divider R39 and R39 for achieving a line level output The output during tape save or type sync out applications will appear as a 5V pulse train but only if the tape out is NOT connected to a deck the decks A C coupling will distort the output 5 5 Tape Input In it s simplest form the tape input consists of an integrator under software control of the 8031 and a threshold detector U1C Input from J5 is passed through a current limiting resistor R112 and on to the integrator C11 C23 R86 The software controls the integration c
43. haracteristics through Q16 via memory mapped l O latch 014 see section 3 2 While the unit is in TAPE SYNC IN mode U14 P12 is held high turning on Q16 and sinking the majority of current through the integrator to ground This provides for faster operation of the detection circuitry D17 is used to prevent leakage of the integrator signals through the control circuitry during LOAD VERIFY operations when U14 P12 is low The threshold detection circuitry surround U1C is relatively straight forward R14 and R15 establish the threshold level with R12 and C9 acting as a filter to stabilize the threshold level and prevent oscillation R21 establishes some hysteresis and R13 is a pullup for the open collector output of the LM339 The output of the 339 is sent directly to the 8031 in the form of an interrupt line Forcing the 8031 to respond immediately to tape input is necessary due to the timing constraints required for I O especially in tape sync situations 6 0 Test Procedures If possible user data should always be saved DataDisk or equivalent recommended prior to servicing While this may not be immediately possible or possible at all it should be attempted as soon as possible HR 16 HR16B Service Manual 1 00 7 6 1 General Testing General testing should at a minimum consist of self test and a short audio test including testing key response and recording and playing back a pattern More extensive testing would include
44. isture The AC power supply plug or cord is damaged The product shows an inappropriate change in performance or does not operate normally or The enclosure of the product has been damaged HR 16 HR16B Service Manual 1 00 iv 03 31 06 General Troubleshooting While this manual assumes that the reader has a fundamental understanding of electronics and basic troubleshooting techniques a review of some of the techniques used by our staff may help l 2 10 11 12 Visual Inspection A short visual inspection of unit under test will often yield results without the need of complex signal analysis burnt or loose components are a dead giveaway Self Test Alesis products that utilize microprocessor control contain built in test software which exercises many of the units primary circuit functions Self test should always be done following any repair to ensure basic functionality Environmental Testing Applying heat and cold heat gun freeze spray will often reveal thermally intermittent components Clock crystals 5 and capacitors are particularly prone to this type of failure Burn in Testing Leaving a unit running overnight often reveals intermittent failures such as capacitors that begin to leak excess current after a significant amount of time Cable Checks Wiggling cables can reveal intermittent failures such as loose cables or poorly soldered headers Remember to check power suppl
45. k ROM CE lines pin 22 such that only one device is enabled at any given time HR 16 HR16B Service Manual 1 00 5 5 0 Analog Signal Paths 5 1 Drum Signal Output The output of the ASIC is 18 bit value This may seem a little strange at first since we are using a 16 bit DAC R63 and 73 75 provide the binary weighted resistor network necessary to achieve a full 18 bit output The PCM 54 DAC adjust circuit consists of R52 R53 R54 C34 trimpot R90 see section 6 3 regarding adjustment The output of the DAC is sent via R68 to the 4052 analog switch U19 where the ASIC controls to which output outi left right or out2 left right the final signal will be sent Note that stereo panning is achieved by sending the same signal to the left and right sides separately Each output section consisting of 1 4 of U20 1 4 of U21 and misc resistors and capacitors serves the dual purposes of filtering and buffering with a little gain added in In the case of output 1 the signal is fed through the volume slider via J11 see section 7 19 regarding differences in wiring before final output to the 1 4 inch jacks 5 2 Piezo Data Slider Input Successive approximation is the method used to determine the value of the keypad piezo crystals keypad velocity and the data slider It is a heuristic approach to the process of analog to digital conversion The idea is to divide the process into short manageable sections Each
46. ld consist of the following pattern data OFEH OFEH OFEH OFEH OFEH OFEH 08CH OFFH This data will count clocks for 126 6 12 clocks 768 clocks divided by 96 clocks per beat 8 beats after which it will loop around since it has reached the end of the pattern Adding the number of bytes in a pattern to the absolute pointer of a pattern should point to 1 byte past the last byte of the pattern SONG DATA FORMAT The following is the format of each song starting with the address pointed to by the absolute pointer to the pattern offset by 8200H 00H 01H 02H 03H 04H 05H 06H xxH LSB of number of bytes in song including header MSB of number of bytes in song including header Step 1 Step 2 Step 3 Step 4 ete Pattern number OFFH end of song Song data must follow these rules HR 16 HR16B Service Manual 1 00 27 1 2 01H Step data 0 99 indicate pattern steps Step data 100 250 indicate tempo change of 50 to 200 respectively Step data of 251 254 are not accessible from the front panel but would correspond to tempos of 201 through 204 There cannot be more than 255 steps in a song Adding the number of bytes in a song to the absolute pointer of a song should point to 1 byte past the last byte of the song SELECT PATTERN OR SONG This command is used to select a pattern or song 02H 03H 04H 05H 0000000xB O pattern 1 song OnnnnnnnB 0 99 pattern or song number 7FH EOX RECORD
47. lty ADC circuit Usually if this is the case Troubleshoot and repair as necessary see the keypad velocity will not work either section 5 2 Replace and retest Faulty ADC circuit most likely a short or open Troubleshoot and repair as necessary see in the binary weighted resistor network section 5 2 Foot switches not working Broken cliff 1 4 jack Faulty 8031 Not retaining memory when power removed Faulty SRAM bypass capacitor blue Replace capacitor and battery Check battery No battery backup Battery is dead monoblock type current see section 2 1 Troubleshoot and repair as necessary CE pin 20 not held high Faulty battery Replace capacitor and battery Check battery current see section 2 1 Not retaining memory when power removed Troubleshoot and repair as necessary No battery backup Battery is not dead power down Drum pads not sensitive to velocity Unit crashes constantly _Faulty 8031 EPROM or SRAM O Faulty DM3AG ASIC pulling down data buss Complaint Possible Cause Solutions e Unit crashes constantly cont Faulty I O latch pulling down data buss Troubleshoot and repair as necessary Faulty front panel cable Replace and retest Incorrect data slider wiring Check slider wiring Repair as necessary HR 16 HR16B Service Manual 1 00 16 Some or all drum sounds are distorted Incorrect EPROM Oftentimes users will Check and replace if necessary attempt
48. mpt to read it s instructions before the data was valid The solution to this effect was to leave the EPROM permanently enabled and use OE pin 22 which operates much faster to control it s access to the data buss On revision A PC boards this requires cutting a trace scraping the solder mask from the closest ground trace and adding a jumper see diagram 11 On revision CA PC boards this requires that pin 20 of the EPROM be lifted out of the socket and a jumper installed see diagram 10 On revision AQ PC boards pin 22 of the EPROM must also be lifted the end away from the 8031 of R110 is lifted anda jumper between the two is added While non National EPROMs do not seem exhibit this scenario it s recommended that this update be performed on all units 7 5 RF resistor Revision An improvement of R F characteristics can achieved by installing a 4700 into the ASIC clock line The best location to accomplish this is between the 74HC04 U6 and the nearby feed through The trace on the solder side of the PC board can then be cut see diagram 12 for details 10 7 6 10K MIDI Resistor R5 All Revisions Since the HR 16 was released we have found that a 10K resistor provides a better signal threshold level to the opto isolator than the original 47K specified in the design If the older value of 47K is found then a Solder 470 ohm K dered i Cut trace on solder side Resistor from pin 2 12K or 13K resi
49. ointer to pattern 99 LSB of absolute pointer to pattern 99 DON T ALTER LSB of absolute pointer to first byte past SONG 99 data MSB of absolute pointer to first byte past SONG 99 data DON T ALTER LSB of FF00H minus data in OCDH amp 0CEH MSB of FF00H minus data in OCDH amp 0CEH DON T ALTER Shuffle amount 0 24 0250906 DON T ALTER Tempo 20 255 Quant clock count must correspond to Quant value 0 9 96 64 48 32 24 16 12 8 6 1 Quant value 0 9 DON T CARE DON T ALTER MSB of absolute pointer to song 00 LSB of absolute pointer to song 00 MSB of absolute pointer to song 01 LSB of absolute pointer to song 01 MSB of absolute pointer to song 02 LSB of absolute pointer to song 02 MSB of absolute pointer to song 99 LSB of absolute pointer to song 99 DON T ALTER DON T CARE DON T ALTER DON T CARE PATTERN 00 DATA The pattern and song data must be dealt with in a specific manner 1 pattern and song data must be in consecutive order i e pattern 05 data cannot be before pattern 02 s data The order for the data should be pattern 00 through 99 followed by song 00 through 99 HR 16 HR16B Service Manual 1 00 25 2 If a pattern or song does not exist its MSB pointer will 0 which is an illegal pointer address Since there will be no data for this pattern it is skipped i e if pattern 04 is empty pattern 05 s data follows after pattern 03 s data 3 There can be no gaps in the data Pattern 01 s
50. ressing the VOICE button simultaneously also starts the DAC adjust routine While this routine is running adjust R90 the trimpot near the PCM 54 so that a minimum of noise is heard during each drum hit A DAC that is out of adjustment will buzz particularly at the end of the sample Note that you may have to turn your amplifier up in order to hear this signal Once the adjustment is complete hitting the STOP button ends the DAC adjust routine HR 16 HR16B Service Manual 1 00 8 7 0 Updates and Corrections New SRAM supply Circuit location Guide for Revision AQ Diagram 6 To pin 1 of 7805 regulator 47K New SRAM supply 2NA401 Location guide For Revisions A amp AC 4c m mm 8 E M A M 0 1 3 M 83 e V202 Diagram 8 HR 16 HR16B Service Manual 1 00 4 7K To Raw 5 1N4148 2N4401 1N914 To SRAM Power To regulated 5V New SRAM Supply Circuit Diagram 7 7 1 New SRAM Supply Circuit All Revisions The new SRAM supply circuit See diagram 7 supplies a solid 5V to the SRAM preventing input data from being higher in amplitude than the supply voltage which can cause data corruption First remove the original diode D8 then install the new circuit Diagram 8 shows the location to install the circuit in Revision A amp CA PC boards while diagram 6 shows the location 7 for revision AQ PC boards The installation of this circuit
51. rmining that the HR 16 is ready to receive additional MIDI information For example selecting a pattern or copying a pattern can cause a delay in which the HR 16 will ignore incoming MIDI information if its input buffer overflows By sending this command after a copy pattern command command 5 and then waiting for the response before sending any additional commands it can be insured that the HR 16 will not miss any information 0000000xB xz0zMIDI inquiry x 1 MIDI response F7H EOX 0AH ERASE PATTERN OR SONG This command is used to erase the currently selected pattern or song It will be ignored if in play mode F7H EOX HR 16 HR16B Service Manual 1 00 30 12 0 Service Manual History 7 27 95 V1 00 HR 16 HR16B Service Manual 1 00 1st release 31 12V 1 2 5V 1 3 15 12V 1 1 1 4 inch jacks 6 1 8 inch cable 8 12MHz 3 1N5231B 9 18 4 4052 6 16 18 5 5 1V zener 3 6 6MHz 5 7 74HC04 10 18 74HC04s 6 74HC138 4 15 18 74HC540 6 18 7805 1 18 7812 1 18 7912 1 18 8 8031 3 4 5 6 7 8 10 11 13 15 16 18 A A 1 4 6 7 9 10 11 12 13 15 28 27 A0 A19 5 A15 4 A8 A10 4 adapter 1 adapters 7 ADC 16 Address Buss 5 8 15 adjustment 6 8 9 17 Analog switch 6 16 analog to digital 6 AQ 1 6 9 10 11 13 15 16 18 ASIC 3 4 5 6 10 15 16 17 18 19 audio test 8 Auto start 24 B Battery backup 2 3 8 12 16 batt
52. ry 15 solder mask 10 11 SONG DATA 25 26 27 28 Song Pointer 20 SRAM 1 2 3 8 9 15 16 18 SRAMs 2 9 standby current 2 STB 5 Steering diode 2 STEP EDIT 29 Stereo panning 6 STRES 5 SYSEX 22 23 24 29 T tape backup 6 HR 16 HR16B Service Manual 1 00 33 tape input 6 8 13 Tape output 6 7 tape sync 6 20 threshold 3 4 11 12 13 16 TOM 1 16 24 26 TOM 3 16 24 27 trimpot 6 8 11 18 troubleshooting 3 15 TXD 3 4 11 U 01 3 6 16 18 U10 1 18 U11 3 18 U13 4 15 18 U14 4 18 019 6 18 U2 6 18 U20 2 6 14 16 18 921 6 16 U22 4 18 U3 6 UA 4 16 U6 10 13 18 U8 1 18 US 1 18 update 10 30 user error 6 15 16 V Vcc 15 velocity 6 16 voltage doubler 1 volume slider 6 13 16 17 wave shaping 6 7 write 3 4 2 21 3 18 HR 16 HR16B Service Manual 1 00 NOTES 34
53. significant binary weight starting with the Most Significant Bit is taken in turn thus requiring only 8 comparisons to achieve a final value 74HCO04s U2 and replaced by a single 74HC540 02 in revision AQ PC boards combine with the binary weighted resistor network R16 R20 and SIP R22 to form a simple 8 bit digital to analog converter The 8031 sends values to the DAC via it s internal I O ports The analog equivalent of these values is compared to the actual input signals via comparators U1 pins 2 4 and 5 for the data slider and U1 pins 8 9 and 14 for the piezos The 8031 reads the result of the comparison through I O port P3 4 pin 14 or port P3 5 pin 15 and proceeds according to that result The data slider is read directly via R23 with C16 acting as a filter to reduce jitter However the piezos require a little bit of wave shaping and translation before they can be read First the signal is coupled by C50 and rectified by 019 Q3 is then used to translate the signal into a to 5V range the piezos can produce up to about 50V The signal is now ready for conversion 5 3 Tape I O Tape output is very simple while tape input is somewhat more complicated This is due to the fact that tape backup and tape sync have different requirements Data transfers need data integrity which implies guaranteed highs and lows while tape sync needs tight timing and fast transistions It s important to remember that not all tape
54. stor soldered in To feedthrough parallel with R5 will achieve the Diagram 12 desired threshold level 7 7 MIDI Pullu MIDI Pullup Revision A U Location Some early units were prone to sending false or incorrect 4 Add 4 7K data through the MIDI out This was traced to insufficient pull up pee resistance in the 8031 s TXD port This can be solved by installing 4 7K resistor between R6 and H7 as shown diagram 13 Diagram 13 7 8 RF Shields Revision In an effort to further reduce the R F emissions of the HR 16 self sticking R F shield was introduced Care should be taken when installing the shield as wrinkles in the shield may easily cause shorts to the main PC board The tab of the shield should make a firm mechanical contact to ground when the board is in place for a short time revision CA main PC boards were manufactured with the solder mask covering the ground plane that will need to be scraped off in order to achieve a proper connection If this is not done correctly this may actually create more R F noise than before the shield starts acting as a capacitivly coupled antenna Also note that some PC board revisions have the DAC adjust trimpot on the bottom of the board for external access On these units either cutting a out a circle around the trimpot or the addition of electrical tape will insulate the trimpot from the shield Jumper 12 7 9 LCD Contrast A
55. ttern number to play when the current pattern is finished This functions exactly as if the new pattern number had been selected from the keypad If a song is playing MIDI program commands will still be ignored 5 Added feature that allows MIDI program change commands to select songs if the HR 16 is in song mode and not playing Previously MIDI program change commands were ignored while in song mode 6 Revised service routines so that the DAC test can be entered directly by holding PATT and pressing VOICE while not in PLAY mode The DAC test now plays a tom at low level once per second for easier calibration Not released HR 16 HR16B Service Manual 1 00 20 8 25 88 1 09 2 2189 2 00 2 2 90 2 01 7 3 90 2 02 3 10 92 2 03 1 Fixes bug that caused the HR 16 to send out an incorrect MIDI song position pointer if any tempo change steps occurred in the song previous to the current song position 2 Fixes bug that caused the HR 16 to send out an incorrect MIDI song position pointer if an empty pattern 8 beats no drum events was used in a step of a song previous to the current song position 3 Added feature that allows spot erasing while in record mode when quantize is off This means that the erase button and a drum button can be held down while recording with quantize off in order to erase all drum events quantized or not that occur during the time that the buttons are held down 4 Added more steps of shuffle resolution and ch
56. ubleshoot and repair as necessary were used originally but some were found to be unreliable We have since switched to using 1N4004s exclusively Blown DM3AG ASIC occasionally these devices will short and pull down the 5V supply rail Remove ASIC and attempt power up Also note that this type of ASIC failure usually causes the ASIC to become extremely hot to the touch Blown 5V filter capacitor C5 Troubleshoot and repair as necessary Usually blown capacitors will display a distended appearance Broken lead on power choke Troubleshoot and repair as necessary see section 7 16 Unit powers up but does not function No LCD display all LEDs on buttons don t work etc LCD shows no or scrambled display the rest of the unit seems to function normally Intermittent reset Blown monolithic filter capacitor Any of the small blue RAM capacitors used as bypass capacitors can become shorted and pull the rail low We are currently using ceramic disk Troubleshoot and repair as necessary Note that when these capacitors fail they often turn brown from overheating and some will occasionally just burn up capacitors as replacements exclusively Unit is simply crashed Reinitialize memory and test Troubleshoot and repair as necessary see section 7 13 Troubleshoot and repair as necessary see section 3 X Troubleshoot and repair as necessary C 20 leaking excessively Faulty 8031 E
57. uld be unplugged from the AC outlet 5 Foreign Objects and Liquids Take care not to allow liquids to spill or objects to fall into any openings of the product 6 Water or Moisture The product should not be used near any water or in moisture 7 Heat Do not place the product near heat sources such as stoves heat registers radiators or other heat producing equipment 8 Ventilation When installing the product make sure that the product has adequate ventilation Improperly ventilating the product may cause overheating which may damage the product 9 Mounting The product should only be used with a rack which the manufacturer recommends The combination of the product and rack should be moved carefully Quick movements excessive force or uneven surfaces may overturn the combination which may damage the product and rack combination 10 Cleaning The product should only be cleaned as the manufacturer recommends 11 Service The user should only attempt the limited service or upkeep specifically described in the operating instructions for the user For any other service required the product should be taken to an authorized service center as described in the operating instructions 12 Damage to the Product Qualified service personnel should service the unit in certain situations including without limitation when Liquid has spilled or objects have fallen into the product The product is exposed to water or excessive mo
58. vironment such as near the CA7 OOl pF ocean We have since switched to using PC Circuit Change Boards with carbon contacts We recommend Diagram 15 replacing the older type PC Boards with the newer variety In the event that the newer board is unavailable emergency rushes etc it is possible to clean the old keypad contacts with a pencil eraser While this will restore operation to the unit such a measure is strictly temporary as the contacts will eventually reoxidize 7 12 Lifting R41 e Revision It was found that the feed through below R41 located near the battery would occasionally short directly to the resistor above it If this happens then battery backup will not function The simplest solution is to lift one or both leads of the resistor slightly with a soldering iron pushing them up through from the bottom of the board is probably the easiest This should prevent any physical contact of the resistor to the feed through 7 13 Reset Capacitor e Revision amp CA The blue monolithic block RAM capacitors used throughout the board were found to be unreliable when used in timing critical applications due to excess leakage current C20 is a prime example of just such an application If C20 leaks too much it acts as a voltage divider with R24 and never exceeds the threshold voltage required to finish the reset process A large percentage of locked up units can be repaired by replacing this capacitor with either a ceramic
59. xxxxxxyB LSB of number of unpacked bytes of data after header OyyyyyyyB ify 0 then x x 1 O00nnnnnB copy mode 1 16 copy drum 17 copy song The data is packed as 8 MIDI bytes per 7 data bytes as described data above in the MIDI bulk dump explanation It contains a complete pattern or song 00000000B This extra byte is required for proper operation F7H EOX When transmitting any copy function it is recommended that a pause of one second be inserted between the copy mode byte and the data that follows it to insure that the receiving HR 16 has enough time to move memory around to make room for the new pattern or song In addition it is recommended that a delay be added before sending additional MIDI commands since it may take a few seconds for the copy operation to be complete during which time MIDI data will be ignored The amount of time required will be dependent on the length of the patterns or songs being copied and the amount of free memory available STEP EDIT MODE This command is used to enter or exit step edit mode as well as for stepping through the edited pattern If it is received while in song mode it will be ignored If a step command is given while not in step mode it will also be ignored The HR 16 will always transmit the current quantize and swing settings before sending an enter step command When receiving a step to next beat any additional drums on the existing beat will be skipped When re
60. y cables as well Flexing the PC Board Poor solder joints and broken traces can often be found by pressing the PC Board in various places Tapping Componants Somtimes tapping on a component particularly crystals will cause it to fail Power Down up Turning the unit off and back on rapidly several times may reveal odd reset and or power supply failures Reset Threshold A Variac variable transformer can be used to check reset threshold levels This can be particularly useful in helping customers with low line problems Compressors Using a compressor limiter is often helpful when attempting to solve low level noise problems as well as assisting with DAC adjustments Sweep Tests Sweep generators are very useful in checking the frequency response envelopes of anti aliasing filters Piggybacking Piggybacking 5 is particularly useful when troubleshooting large sections of logic This is especially true when working with older units HR 16 HR16B Service Manual 1 00 03 31 06 TABLE OF CONTENTS ii READ THIS listen t ii Moe iii SAFETY SUGGESTIONS en tae eec a do vase iv General Troubleshooting sse V 1 0 General Description 1 1 1 Main PC Board Revisions 1 2 0 Power Supply ae crates ee ates eges CY e vee 1 2 1 Battery BackUp aede ds 2 2 2 PUP GIICUIE li
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