THIS BULLETIN COVERS: . EPS DIAGNOSTICS I . EPS
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1. April 15 1989 THIS BULLETIN COVERS EPS DIAGNOSTICS EPS THE 7501 MAIN BOARD AND THE 10002 MAIN BOARD EPS DIAGNOSTICS A number of EPS s have been incorrectly diagnosed as having a faulty main board when the real problem was a faulty power supply The following are the most common problems which could be caused by a faulty power supply 4 Back of Unit 4 To Transformer a Heat Sink J4 DAE 4 0 Amp 250 V m TO o J Eo 40am 50V y H 6 DOR 15am 250V a O Oe Hs QL 15Amp 250V O D 0 gt O 1 5 Amp 250 V lt 4 7 To Display Part Number __ POWER SUPPLY BOARD To Disk Drive To Main Hamess screened se Power Supply Voltage Check Points Heat Sink 1 PROBLEM Hum or buzz in audio output EPS crashes randomly or problems develop after inserting a memory expander SOLUTION Check the voltages on the power supply at J4 with the power supply loaded main board and display board connected Using pin 11 as ground the voltages on pins 14 16 and 16 of J4 should be 4 75 to 5 25 VDC The AC ripple on these pins should be less than 50mV If the voltages are not within this range or the AC ripple is greater than 50mV replace the power supply 2 PROBLEM EPS is dead on power up SOLUTION Perform solution 1 above If no problem is found check the voltages on the power supply at J3 Using pin 23 as ground the voltages on pins 27 and 28 of J3 should be 22 7 to 31 5VDC If the voltages are not within this range replac2. Insert a small Phillips screwdriver all the way into a key s spring b Push down to expand the spring then move the bottom of the spring away from the keyboard Be sure to put the springs in a safe place they have a tendency to roll 3 Remove the keys to expose the coil board connectors white keys first a Just below the key number near the spring hole on the key there is a rectangular opening b There is a clip that holds the key in place Insert a small thin flat blade screwdriver into the opening IMPORTANT These clips do not need a lot of pressure to be released If a clip breaks due to too much pressure contact ENSONIQ Customer Service for a replacement key c While lifting up on the back of the key near the spring hole push the top of the screwdriver toward the back of the keyboard to release the clip C Solder the connector leads together 1 Hardwire the connector leads together horizontally a Tf there are two rows of leads on each board do not solder them together The twenty pin dual row connector is a better connector and does not need to be hardwired D Reinstall the keys 1 Put the black keys on first They go on where there are single keystops 2 Place the front of the key on first then press the back of the key down until the clip catches and holds it in place 3 Place the white keys back on in order Make sure that the clip for each key is engaged 4 To reinstall the springs place the spring into its ho
3. actory Sometimes removing the keyboard from the unit would shift the connector and break through the oxide so that all pins were making contact Losing contact on just one pin even briefly can cause a unit to lock up freeze or have a calibration error In the investigation of the keyboard failures it was also found that there were some weaknesses in the design of the KPC board Changes made to the KPC board make the design more robust in terms of heat dissipation and clock generation However just updating the KPC only is not sufficient for many keyboards The main failure on keyboards is caused by the coil board to coil board connector Remember that a KPC board can only be replaced with the whole keyboard assembly as it contains information specific to its particular coil boards and keys in its memory Other small things were found and corrected as well but the main cause of failure is the coil board to coil board connector breaking contact Changes were made to the KPC O S EPROM to make the keyboard software more reliable but does not correct the basic problem Changing two resistor values described in Service Bulletin 9B helped but does not correct the basic problem therefore the resistors are no longer included in the KPC EPROM Update Kit All new units from the factory will have the KPC board changes and the coil boards hardwired together until newly designed coil boards am in production Any units that come into the factory for repai
4. ddle six keys as described in Section E call ENSONIQ Customer Service for a replacement keyboard assembly Tools Needed 0 Phillips screwdriver safety glasses small flat blade screwdriver soldering iron and sol amp r 2 5mm hex wrench scribe see Section K jumper wires from ENSONIQ Cor Page ection PISTOL ice raian da J A Types of Keyboards KPC Versions and Coil Boards 2 Troubleshooting a Unit with a Poly Key Keyboard Problem ORE 4 D Removing the Keyboard from the unit aoaaa E Remove Keys 3 Sn Ga 5 F Solderthe Connector Leads Together 6 Reinstall the Keys H Installing the Keyboard into the unit 6 Checking the KPC O S Version K Keyboard Ribbon Cable Problems 7 Service Bulletin 12 Poly Key Keyboard Coil Boar amp PIN 9360 0091 01 A A History Keyboard failures have been caused by two problems First when the connector between the two coil boards is intermittent it may cause a keyboard calibration failure random notes to be played or ERROR 144 The fix is to make a reliable connection between the two coil boards hardwire the two coil boards together Second a few failures have been caused by faulty ribbon cables and wire harnesses While investigating Keyboard Calibration errors it was found that a break in the interconnection of the two coil boards can cause a variety of problems The coil board connectors move in a horizontal plane while the force
5. e the power supply If no problem is found check the voltage at pin 25 of J3 It should be 29 to 37 2 VDC If the voltage is not in this range replace the power supply 3 PROBLEM EPS has disk drive loading problems SOLUTION Perform solution 1 above If no problem is found check the voltages on the power supply at J2 Using pin 11 of J4 as ground the voltage on pin 22 of J2 should be 11 4 to 12 6 VDC The AC ripple on this pin should be less than 50mV If the voltage is not within this range or the AC ripple is greater than 50mV replace the power supply THE 7501 MAIN BOARD AND THE 10002 MAIN BOARD Units with serial numbers 16582 or higher 240V 502603 contain a new version of the EPS Main Board The 10002 board is a new layout of the 7501 Main Board with the tower board included a new square gate array chip that replaces several individual chips and a different size RAM chip When replacing a main board you should replace ii with the same version that is in the unit Replacing a 7501 Maln Board with a 10002 board should be done only when 7501 malin boards are not available to you The 10002 board has all of the connectors except the disk drive connector J2 in a different place from the 7501 board If you must replace a 7501 Main Board with a 10002 Main Board three cables must be replaced D o not attempt to switch boards without acquiring these cables from ENSONIQ Customer Service Keyboard Cable Main Board Power Cable attach
6. ed lo main harness and SCSI Cable if applicable DIRON N 8 9 Remove the 7501 Main board as described in the EPS Service Manual Clip the four wire ties that hold the main board power cable 9 pin to the main harness Discard this cable Insert the new 10002 Main Board as described in the EPS Service Manual Attach the new main board power cable to the power supply at J4 and to the main board at J10 Reconnect the cables from the display board J8 wheels J9 and disk drive J2 Use two wire ties to bundle the new main board power cable out of the way NOTE Leave the wheels cable out of the wire ties If applicable install the new longer SCSI cable the 34 pin ribbon cable from the SCSI board to the auxiliary expansion connector J6 on the main board Replace the existing keyboard cable on the keyboard with the new longer keyboard cable Re install the keyboard as described in the EPS Service Manual 10 For best results boot the unit with the latest OS disk 2 35 or higher March 20 1991 This Bulletin Covers Soldering jumper wires between the two Poly Key Keyboard Coil Boards that have a twelve pin single row connector A twenty pin dual row connector was used after November 1990 and does not need to be hardwired This bulletin should only be done after performing Service Bulletin 9B to ensure that the unit has the latest KPC version and resistors To form an absolute connection between the two coil b
7. exerted on the connector by playing is in a vertical direction If one pin doesn t make contact or loses contact briefly the keyboard might not calibrate might freeze up button presses have no effect show an ERROR 144 or might start playing random notes Hardwiring the two boards together forms an absolute connection The tin connectors most commonly used coating material for connectors builds up some oxide over time This oxide is cleared by a wiping action when the pins are moved in their plane here it would be horizontally However the force on the coil board to coil board connector is vertical ONLY no movement horizontally at all and therefore the oxide would not be cleared off This oxide buildup could cause one or more pins to lose contact over time This problem was masked by the type of flux that we use Service Bulletin 9B This flux does leave some residue and we now clean all connectors that hang over the edge of the board for example the Keypad Display connector or hand solder them into the board Cleaning the connectors helped temporarily because the wiping action of separating the coil boards and then reconnecting them broke through the oxide buildup on the connector This oxide buildup problem was very difficult to find because shipping a unit from a customer to the factory could cause the coil board to coil board connector to shift enough to break through the oxide so that the unit would work fine when it reached the f
8. four 4 screws that fasten the control panel and raise the panel 3 Place the unit upside down on a soft surface and remove the ten 10 screws that attach the keyboard to the case Figure 3 Bottom of Case 4 Carefully turn the unit tight side up Raise the control panel and disconnect the 20 pin keyboard ribbon cable from the main board using a scribe or similar tool see Section K paying particular attention to the Polarity 5 Remove the keyboard from the case by gently lifting up the front of it while pulling it toward the front of the unit Once the rear of the keyboard has cleared the control panel mounting tabs the keyboard can be removed from the keyboard cavity E Remove Middle D through G Keys from the center of the keyboard Figure 4 Remove these six keys 1 Place the keyboard with the keys up on a level surface 2 Remove the key springs a Insert a small Phillips screwdriver all the way into a key s spring at the tear of the key b Push down to expand the spring then move the bottom of the spring away from the keyboard Be sure to put the springs in a safe place they have a tendency to roll 3 Remove the keys to expose the coil board connectors white keys first a Just below the key number near the spring hole on the key there is a rectangular opening b There is a clip that holds the key in place Insert a small thin flat blade screwdriver into the opening IMPORTANT These clips do not need much pre
9. lay shows KPC VERSION YYY K Keyboard Ribbon Cable Problems We have found that some units have developed further problems once a keyboard is installed This has been a result of improper handling of the keyboard ribbon cable We suggest removing the cable connector using the angled end of a scribe see below SCRIBE Figure 6 Scribe These can be found in the following catalogs e Techno Tool catalog 38 page 204 part number 400PR144 e Newark catalog 110 page 1024 part number 76 1510 Note for VFXSP Only Be sum to route the keyboard ribbon cable around the square 68 pin gate array on the main board After you insert the keyboard into place lift the keys slightly and visually check to make sure that E A misplaced or crimped cable can result in what seems to be a keypad display problem because keypad display information is passed through the KPC board to the main board You may call ENSONIQ Customer Service for a new cable with these folds Bottom view of ferrite bead end of cable 20 pin connector gt gt gt to Main Board 83 H S g gt Figure 7 zal New Keyboard Cable AS Routing for the VFX SD Service Bulletin 12 page 7
10. le on the key open side up Insert the small thin Phillips screwdriver into the spring and push down and out to expand it Then move the bottom the spring into the keyboard frame E Install the Keyboard into the unit 1 the IMPORTANT mispinned F3 the 2 Insert the keyboard rear first into the unit at the front of the keyboard cavity Gently slide the keyboard toward the rear of the unit lowering the front of the keyboard as needed to clear the control panel mounting tabs Lift the keys slightly to be sure that the keyboard cable lies flat beneath the keyboard and is not pinched under the keyboard frame 3 Tum the unit upside down on a soft surface and replace the ten 10 screws that secure the keyboard to the case 4 Power up test the unit and close the control panel page 2 Service Bulletin ll This Bulletin Covers The latest information on the Poly Key Keyboard Some information is new and some was previously contained in Service Bulletins 9B and 11 Please take the time to read this bulletin so you will be up to date on current developments This bulletin completely replaces Service Bulletins 9B AND 11 IMPORTANT If the coil board to coil board connector is a 12 pin single row connector remove the middle six keys as described in Section E hardwire it together follow this bulletin This is for both foam and foamless keyboards If the coil bard to coil board connector is a 20 pin dual row connector remove the mi
11. n and out to expand it Then move the bottom the spring into the keyboard frame and remove the screwdriver from the spring to lock it in place Installing the Keyboard into the unit Making note of the proper polarity connect the keyboard ribbon cable to the main board IMPORTANT If ribbon cable is mispinned fuses F3 and F4 on the power supply will 2 3 4 Insert the keyboard rear first into the unit at the front of the keyboard cavity Gently slide the keyboard toward the rear of the unit lowering the front of the keyboard as needed to clear the control panel mounting tabs Lift the keys slightly to be sure that the keyboard cable and disk drive cable when present lies flat beneath the keyboard and is not pinched under the keyboard frame Turn the unit upside down on a soft surface and replace the ten 10 screws that secure the keyboard to the case Power up test the unit and close the control panel page 6 Service Bulletin 2 J Checking the KPC O S Version Number SD 1 VFXSP and VFX While holding down Presets press Master The display shows ENSONIQ SOFTWARE ROM V X XX KPC YYY X XX denotes the main operating system and YYY indicates the KPC O S version See note in Section K for VFXSD keyboard ribbon cable problems EPS 16 PLUS and EPS Press Command then Envl The display shows NO COMMANDS ON PAGE Press the right arrow button until the display shows SOFTWARE INFORMATION Press Enter Yes until the disp
12. oards you will be hardwiring the coil boards together using the wires provided You will need to remove the keyboard from the unit and then only remove six keys from the middle of the keyboard to expose the solder side of the connectors Tools Needed 2 5mm hex wrench small flat blade screwdriver Phillips screwdriver jumper wires from ENSONIQ soldering iron solder WAN Service Bulletin 1 Poly Key Keyoard Coil Boards PIN 9560 CO 86 01 A A Remove the Keyboard from the unit 1 Remove all external cables connected to the unit including the Power cord 2 Using a 2 5mm hex wrench remove the four 4 screws that fasten the control panel and raise the panel 3 Place the unit upside down on Front of Case Keyboard Side a soft surface and remove the z g g ten 10 screws that attach the keyboard to the case Bottom of Case 4 Carefully tum the unit right side op Raise the control panel and disconnect the 20 pin keyboard ribbon cable from the main board paying particular attention to the polarity 5 Remove the keyboard from the case by gently lifting up the front of it while pulling it toward the front of the unit Once the rear of the keyboard has cleared the control panel mounting tabs the keyboard can be removed from the keyboard cavity B Remove Middle D through G Keys from the center of the keyboard see figure on p 1 1 Place the keyboard with the keys up on a level surface 2 Remove the key springs a
13. r will also have this done as a routine part of the service page 2 Service Bulletin 12 B Types of Keyboards As you may or may not be aware there are two types of Poly Key keyboards ones with foam pads on the under sides of the keys and foamless ones without the foam pads We currently manufacture foamless keyboards with coil boards that have reference coils Types of WC Versions Each type of Poly Key keyboard uses a different KPC O S version The current KPC O S versions are shown below KPC version Keyboard and Coil Boards 150 white foam pads on the undersides of the keys 203 grey foam pads on the undersides of the keys 227 foamless no reference coil 233 foamless with reference coil The KPC O S version is typed on the white label on the EPROM U2 on the KPC board The KPC board is the small circuit board 3 75 x 4 25 located on the underside of the keyboard assembly See Section J for information on how to check the KPC O S Types of Coil Boards There are two types of foamless keyboards ones with a reference coil s extra coil s in a different row than the other coils and ones without reference coil s With the keyboard assembly removed from the unit the reference coil s may be seen on the top edge of the coil board below the lowest key the left side of the keyboard see below If you wish you may remove the lowest key see Section E to get a better view of the coil board Coil Board Curren
14. ssure to be released If a clip breaks due to too much pressure contact ENSONIQ Customer Service for a replacement key c While lifting up on the back of the key near the spring hole push the top of the screwdriver toward the back of the keyboard to release the clip d Remove the white keys first then the black keys We suggest keeping the keys in order to make them easier to put back on Service Bulletin 2 page 5 With the middle D through G keys removed from the center of the keyboard F SINGLE ROW Wa Figure 5 12 pin coil board to coil board connector Solder the Connector Leads Together Using the jumper wires provided hardwire the connector leads together horizontally IMPORTANT If there are two rows of leads on each board do not solder them together If 1 2 3 4 H 1 the connector is a twenty pin dual row contact ENSONIQ Customer Service for a replacement keyboard Reinstall the Keys Put the black keys on first They go on where there are single keystops Place the front of the key on first sliding the slot in the front of the key over the keystop on the keyboard frame then press the back of the key down until the clip catches and holds it in place Place the white keys back on in order Make sure that the clip for each key is engaged To reinstall the springs place the spring into its hole on the key open side up Insert the small thin Phillips screwdriver into the spring and push dow
15. t Comments to Coil Boa rd K C Version We used more than one Lonnesur Coil board part number for e this version KPC 227 The 12 pin 227 only absolute reference is single row a foamless keyboard with no reference coil PART NUMBER You ma th y use the part 4090009601 number as a reference if 12 pin 233 you have dismantled the i keyboard single row Figure 1 Call ENSONIQ for a p replacement keyboard nj You may use the part number 0 pin 2 33 as a reference if you have dual row dismantled the Keyboard m y Service Bulletin 2 page 3 C Troubleshooting a Unit with a Poly Key Keyboard Problem z Keyboard Problem Remove the center six keys from the keyboard see Section E Do the coil boards have a Call ENSONIQ 12 pin or 20 pin 20 pin for replacement connector See Figure 5 keyboard 12 pin Hardwire the coil board to coil board connector together see Section F Are there grey foam pads on Ves man a ons the under side of each key see Section J No Are there Call ENSONIQ reference coil s for replacement See Section B keyboard T yr Make sure that the KPC EPROM is 233 or highe Are all of the wires see Section J making contact Yes No Figure 2 3 Keyboard Problem Za Page 4 Service Bulletin 72 D Removing the Keyboard from the unit 1 Remove all cables connected to the unit including the Power cable 2 Using a 2 5mm hex wrench remove the
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