Lexmark 4049LMO Service Manual - Page 47

4049-XXX sure the voltage to the fuser lamp during a POR; it should be line voltage until the 922 Error is displayed, if it does not, replace the LVPS, the fuser, and the fuser wiper. If the voltage to the fuser lamp is the not the same as the line voltage, replace the LVPS. If the lamp, fuser power cable, thermal fuse, thermistor and lamp voltage are OK, check J4-16 to see if the engine board is sending the correct signal to the TRIAC. At POR this signal should go to +5 VDC and then immediately drop to 0 VDC until the fuser is warm; if it does not, replace the engine board. If the signal is OK, replace the LVPS. Fuser: 923 or 924 Error Check the connection and continuity of the cable from the fuser exit sensor board to engine board J8. Check the thermistor condition and connection. Check the thermistor resistance at engine board J8-3 to J8-4. It should be from 100K Ohms to 260K Ohms when cold; it may be as low as 2.3K Ohms when hot, but increase quickly as the fuser cools. Honeycomb (Areas of the page are covered by faint 6 mm circles.) This print defect is usually caused by the print cartridge. If it is not the problem, verify that the tab on the transfer roll housing is touching the contact on the HVPS; the transfer roll housing should have continuity to ground. Make sure the HVPS ground lead to the side frame is in place and making good contact. Horizontal Void or Streak This is usually due to the cartridge not being installed correctly. Check the printhead area for obstructions, and check the mechanical workings of the print cartridge and printhead shutter. If nothing is found see "Blank Page" on page 2-14 and follow those instructions. Diagnostic Information 2-20