Printer Service Manual

4026-0XX
Diagnostic Aids 3-1
3. Diagnostic Aids
This chapter explains the tests and procedures you can run to
identify printer failures and verify that repairs have corrected the
problem.
Power-On Self Test (Post)
The printer performs the following Power-On Self Test when
powered on:
1. All LEDs come on solid.
2. The fan turns on for 2 seconds.
3. All the LEDs turn off.
4. The engine board checks the status of the cover interlock
switch.
5. The LEDs begin to turn on then off continuously.
6. The fan turns off.
7. The engine board checks the status of the paper exit sensor.
8. The engine board checks the status of the thermistor.
9. The fuser lamp turns on.
Note: The printer may be idle for up to 40 seconds as the fuser
warms to operating temperature. Printer idle time is shorter if
the fuser is already warm.
10. The polygon motor (printhead motor) turns on.
11. The main motor turns on.
12. The paper feed gears turn.
13. The print cartridge drive gear engages.
14. The paper feed take-up shaft and D-roll assembly rotates to
home position. (The paper feed lift plate assembly is in the
down position).
15. All the LEDs turn off.