Print Quality Defect Charts - LPT Home Page
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1. Service Edge Page 8 PRINTER TECH ARTICLE Universal Print Quality Defect Charts After paper jams print defects are the most common printer error They are generally easier to correct than jams They give you the possibility of a head start because the customer can fax or email you a sample before you visit This sample can be compared with print defect samples in this article or in the appropriate manual and lead you in the right direction For those times when you are without a manual this article will be especially useful Even if you have the manual this article will prove useful as we emphasize key parts while the omitting the unlikely For monochrome laser printers Monochrome printers are simple Just match the defect 3 type with a picture The troubleshooting steps on page six correspond to the numbers of the pictures For color laser printers First determine whether the problem is associated with a specific color Run a print quality troubleshooting page This creates separate prints from each toner cartridge If the problem is isolated to one color either that cartridge is bad or something associated with that cartridge all color printers have separate high voltage contacts for each cartridge and many also have separate high voltage circuits and separate laser scanners for each color To distinguish between the cartridge itself and other things associated with it set the printer to Disable Cartridge Check and swap c2. eee eee ee ee ee ee ee ee eee eee eee eee eee eee eee eee se eeee eee se ees e ees e ee eee eee eeeeeee reese ees eee ees eeeee reese ees ee eee eee eee eee eee eeee eee ees e eee eee seesee eee eee ese ee sees e see ee ees e reese eee see ese ee see ee ese eeees Liberty Parts Team Inc 3517 W Beltline Hwy Madison WI 53713 608 268 7600 FAX 608 268 7619 Service Edge Page 10 all covers and doors properly installed and closed When running tests with some covers missing do not position the printer under a bright light Check the toner cartridge s and fuser for visible defects Run a halfway test pg 11 if necessary to distinguish between these items If the lines are perpendicular to the direction of paper movement and regularly repetitive use the repetitive defect ruler to pinpoint the cause The formatter can cause dark lines It may be possible to determine this by running an engine test which bypasses the formatter 8 Voids A D Gently shake and reinstall print cartridge s making sure the cover is closed securely If this helps the cartridge is close to being empty and will need replacement soon Run an engine test to make sure the formatter is not causing voids If not the formatter this is usually a high voltage problem Check high voltage and ground contacts Make sure paper and toner are within HP specifications Make sure temperature and humidity are within normal limits Replace the high voltage
3. opening when the printer door is being closed Check cartridge drum rotation by making some sort of mark on the drum outside the printable area and observing whether the mark has changed position after a print attempt If not the cartridge or the cartridge drive mechanism may be defective C Ifthe printer has only one scanner make sure that the safety shutter is opening and that the scanner optics have not gotten dislodged The scanner may also be defective The manual may be necessary to help you access the scanner s D Print an engine test see the relevant service manual for details If this prints normally i e you get a page of lines rather than a white page either the formatter or firmware is defective E Other possibilities are the transfer belt or high voltage power supply Replace these one at a time F Various color printers have unique mechanisms that can cause white pages Consult the service manuals We will only mention one because it is so common on the 4600 5500 family of color printers the developer disengagement plate also called the alienation rod or alienation bar on the left side of the printer can fail causing white pages Usually this involves broken gear teeth on the inner surface of the plate Laser Printer Halfway Test The halfway test also called the stop test is a useful way to isolate print image defects To perform the test print something and then stop the paper halfway through the
4. ruler to pinpoint the cause Most often this will either be the toner cartridge or the fuser A halfway test pg 11 may also help to distinguish between these Ghosting also known as offset that happens in the fuser does not necessarily mean the fuser is bad Make sure paper and toner are within HP specifications If paper is heavier or glossier than normal such as envelopes or labels a fuser temperature adjustment may be necessary 12 Distortion A B Check laser scanner optics Clean if necessary Check the toner cartridge and the mechanism that drives it usually the printer s main drive assembly If the cartridge is not turning smoothly in synchronization with paper movement the printed image can be stretched or compressed vertically The formatter can cause distortion It may be possible to determine this by running an engine test which bypasses the formatter 13 Skewing A Run test pages from all trays If skewing occurs from some trays but not others look for unevenly worn rollers or obstructions in the affected trays or in portions of the paper path that are unique to those trays If skewing occurs from all trays look for worn rollers or obstructions in the areas common to all print paths primarily the registration assembly and the surrounding area Replace the registration assembly if necessary If the paper does not appear to be skewing check the alignment of laser scanner including its i
5. artridges If the problem follows the cartridge the cartridge is obviously bad Otherwise match the pictures to these procedures 1 Light Print partial A Gently shake and reinstall print cartridge s making sure the cover is closed securely If this helps the cartridge is close to being empty and will need replacement soon B If light areas are strips in the direction of paper movement as in the picture laser scanner optics may be partially dirty C If one side of the page is light check mechanical alignment between cartridge s drum s if separate from cartridge and transfer elements This can also indicate high voltage problems see next step D If light areas are randomly positioned on page check high voltage contacts to the cartridge s drum s and transfer elements If contacts look good the high voltage power supply may be bad E Inspect the surfaces of imaging elements cartridge s transfer roller or belt etc and even the fuser for visible defects corresponding to the light area on the page 2 Light Print entire page all colors 5 A Check settings in Print Quality Menu In particular if Economode or Economy Mode is on turn it eececereese eee eee eee ee ee ee ew ee ee eee eee eee ose eee e eee eee eee e eee eee ese ee ee eee e eee eee eee eee e see ese esses e eee eeeeee off Also experiment with print density settings Color printers have individual print density setting
6. ble area and observing whether the mark has changed position after a print attempt If not the cartridge or the cartridge drive mechanism may be defective B If the printer has separate scanners for each color check the relevant scanner consulting the service manual if necessary Make sure that the safety shutter is opening and that the scanner optics have not gotten dislodged The scanner may also be defective C Print an engine test see the relevant service manual for details If all colors are present on the engine test either the formatter or firmware is defective D Other possibilities are the transfer belt or high voltage power supply Replace these one at a time Specks on front or back of page A Make sure that paper and toner are within HP specifications eeceeeesec eee eee eee eee eee eee ee ete ee ee eee ee eee eee eee eee ese eee ee eee eee eee ese eee ese ee se ees eeeeeeeeeee For HP Lexmark Xerox Samsung and Okidata printer parts call Liberty Parts Team 868 444 8778 Service Edge Page 9 1 Light Print partial 2 Light Print en 3 Light Print one tire page all colors color color printers 4 Missing Color 5 Specks on back 6 White Lines or on front AxXYyZz AXYYVZZ XxYyZz XXYYZZ 12 Distortion 11 Repeating marks or ghosts 13 Skewing 14 Smudged PA 15 Distortion or 16 Dark Print 17 Dark Color 18 Black or Solid either direction Blurring Color Page 19 Whi
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8. nternal optics and or toner cartridge 14 Smudged lines either direction A If the lines are perpendicular to the direction of paper movement and regularly repetitive use the repetitive defect ruler to pinpoint the cause A halfway test pg 11 may help distinguish between fuser and toner cartridge as possible causes Dirty rollers can cause smudging Printing from different trays can help isolate which rollers are dirty 15 Distortion or blurring A B Check print quality adjustments in menu Run calibrate now on color printers A fuser film that is not turning freely can cause blurring A halfway test pg 11 will determine whether or not the fuser is at fault If the image on the drum as viewed in the halfway test is already blurred the laser scanner optics may be out of focus Replace the scanner If the blurring happens between the toner cartridge and fuser look for obstructions in the paper path Abnormal vibrations can also cause blurring in this area of the printer In color printers blurring can be caused by improper color registration Replace the color misregistration sensor assembly and or the transfer For HP Lexmark Xerox Samsung and Okidata printer parts call Liberty Parts Team 888 444 8778 Service Edge Page 11 AND THIS DEFECT MEANS YOU NEED A NEW TRANSFER ROLLER belt in many printers the sensor assembly is part of the transfer belt 16 Dark Image A Check prin
9. power supply 9 Gray background or light colored background A B D Try another toner cartridge if one is available Check density settings in the menu and experiment with them Sometimes a darker setting will actually reduce background Make sure paper and toner are within HP specifications in particular envelopes heavy paper and labels are susceptible to this problem Make sure temperature and humidity are within normal limits Check high voltage and ground contacts Replace the high voltage power supply if necessary 10 Loose or smearing toner A If toner can still be smeared after printing this is a fusing issue Make sure paper and toner are within HP specifications If paper is heavier or glossier than normal such as envelopes or labels a fuser temperature adjustment may be necessary Consult the appropriate service manual for details In the worst case the fuser may be defective If toner has a smeared appearance but cannot be smeared further check for dirt or obstructions between the toner cartridge and fuser Clean or remove as necessary 11 Repeating ghost images or any repeating mark A eececeeeeeo eee eee eee ee ee ee ee eee oe eo eee ee ee eee eee eo eee eee eee ee see eee ese ees e eee eee eee ee see eee ese see se reese ees e ee ese eee eee ee se sees eee eee eee eeree eee ese eee eeeeeee eee eee eee ee see eee ee ee ee eeee ese eee ese ee see ese eeeeeeeeeee Use the repetitive defect
10. printer by opening the lid This works best if you feed from the manual or MP tray because you can watch the paper feeding Open the lid just as the trailing edge of the page disappears into the printer Now remove the toner cartridge Ideally the page will be stopped between the toner cartridge and fuser with part of the image on the page but unfused and part of it still on the drum in the toner cartridge Observing these two partial images can help you decide where the defect is originating There are three possibilities I There is no defect visible in either partial image Assuming that the defect is not intermittent and happens on every printed page this eliminates everything before the fuser Therefore the defect must be originating in the fuser Il The defect is visible on the paper but not on the drum This eliminates logic boards laser scanner toner cartridge and fuser Either it is a transfer issue bad transfer roller or high voltage or a mechanical issue rubbing or vibration in the area between transfer and fuser IIL The defect is visible in both partial images This eliminates transfer and fuser The defect originates in the toner car tridge high voltage laser scanner or logic boards Further troubleshooting such as the engine test may be necessary to distinguish between these options eececeecece eee eee eee eee eee eee eee eee ee eee eee see ese eee eeeee eee see ese ee see eee esee eee e eee see ese ee s
11. s for each color B Any of the items discussed in 1 light print partial can also cause the entire page to be light A halfway test page 11 can help narrow it down Laser Scanner and high voltage power supply are the two most common causes Note that in a color printer with separate scanners for each color light print in all colors is unlikely to be scanner related since all four scanners would have to be bad Light Print one color only color printers A Check print quality adjustments for the affected color Select calibrate now from the menu this should also be done after replacing any imaging element such as a toner cartridge scanner or transfer belt B Turn on Disable Cartridge Check and swap cartridges between the affected color and another color If the same color is still light that cartridge is bad C If the light color changes to whatever color is installed in the suspect location something associated with that location is bad Check the high voltage contacts The high voltage power supply or transfer belt may be bad If the printer has separate laser scanners the one associated with that slot may be bad Missing color A Make sure that the cartridge of the affected color is properly seated also check the high voltage contacts and that the cartridge shutter is opening when the printer door is being closed Check cartridge rotation by making some sort of mark on the drum outside the printa
12. t quality adjustments especially print density in menu Run calibrate now on color printers B Make sure paper and toner are within HP specifications C Check high voltage and ground contacts Replace the high voltage power supply D Replace the laser scanner note if all colors are too dark on a printer with multiple scanners they are probably not all bad 17 Dark color A Same as 16 except that the scanner is now a real possibility and maybe even more likely than the high voltage since it s only one color 18 Black page or solid color page A If the page has a white border around the outside this is a formatter firmware issue Replace the firmware then the formatter B If there is no border it is a high voltage issue either the toner cartridge is bad or the high voltage power supply is bad or the connections between them are bad 19 White page no error code A If white pages appear between printed pages this may be a software issue try printing something from the printer menu or a paper feed issue multiple pickup replace the separation pad or roller or in some printers incorrect paper size sensing eeceeeee eee eee eee eee eee eee eee eo eee eee eee ee eee ese eee sesso see e eee eee ese ees eee eee ee eseeeeeeeee see ese eeseeeeeee B Make sure that all cartridges and or drums are properly seated also check the high voltage contacts and that the cartridge shutters are
13. te Page io 20 Drum Ground on 4100 21 HV contact inside a LJ 4100 second from right Round HV con error code cartridge Square in lower right is a HV contact tacts in an 8150 right The metal clip is a ground B Clean the printer with a toner vacuum and or run a for obstructions or visible defects that line up with cleaning page the position of the lines Also check and clean the C Ifthe specks occur at regular repeating intervals use scanner optics t is also possible although unlikely the repetitive defect ruler in the service manual or for the transfer roller or belt to cause white lines in in LP T s Technician s Service Edge to pinpoint the this direction cause If the lines are perpendicular to the direction of D Use the halfway test pg 11 to determine whether paper movement and regularly repetitive use the the defect originates in the toner area or the fuser repetitive defect ruler to pinpoint the cause Replace the appropriate item The formatter can cause white lines It may be E Check the high voltage and ground contacts possible to determine this by running an engine test Replace the high voltage power supply which bypasses the formatter Dark lines A Ambient light getting into the toner cartridge can cause dark lines or bars Make sure the printer has 6 White lines 7 A If the lines are parallel to the direction of paper movement check the toner cartridge s and fuser eeceseeee eee
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