Low Heat Error Rap; Open Heat Error Rap - Xerox WorkCentre M20 Service Manual

10.1 Low Heat Error RAP

The fuser has failed to reach the correct operating temperature or a disconnected thermistor
has been detected.
Procedure
WARNING
Switch off the electricity to the machine. Disconnect the power cord from the customer
supply while performing tasks that do not need electricity. Electricity can cause death or
injury. Moving parts can cause injury.
WARNING
Do not touch the fuser while it is hot.
NOTE: If necessary, refer to GP 20 for the acronym list and cross reference lists of more com-
monly recognised part names.
Refer to Wiring Diagram 1 and Wiring Diagram 3. Perform the following:
1. Switch off the machine, then switch on the machine.
2. Go to GP 1. Perform Fuser Temp Check to verify the condition of the thermistor.
3. Go to GP 1. Perform Fuser Control Test to verify the heating lamp.
4. Switch off the machine. Remove the ELA HOU - fuser assembly. Check that the ther-
mistor is in good contact with the fuser roll and is clean.
5. Check for continuity between the two pins on the ELA HOU - fuser assembly, where the
fuser connects to the IPR terminal fuser, PL 4.15 Item 28.
NOTE: A cold fuser will have a resistance of approximately 46 ohms (220V/240V) or
approximately 14 ohms (110V).
6. If necessary, install a new ELA HOU - fuser assembly, PL 9.10 Item 4.
7. If necessary, install a new PBA main, PL 1.10 Item 9.
8. If necessary, install a new SMPS + HVPS, PL 1.10 Item 4.
Status Indicator RAPs
10.1, 10.2

10.2 Open Heat Error RAP

During normal operation, the temperature has dropped below the operating level.
Procedure
Switch off the electricity to the machine. Disconnect the power cord from the customer
supply while performing tasks that do not need electricity. Electricity can cause death or
injury. Moving parts can cause injury.
Do not touch the fuser while it is hot.
NOTE: If necessary, refer to GP 20 for the acronym list and cross reference lists of more com-
monly recognised part names.
Refer to Wiring Diagram 1 and Wiring Diagram 3. Perform the following:
1. Switch off the machine. Remove the ELA HOU - fuser assembly. Check that the ther-
mistor is clean and is in good contact with the fuser roll.
2. Check the wiring from the thermistor to the PBA main.
3. Check for continuity between the two pins on the ELA HOU - fuser assembly, where the
fuser connects to the IPR terminal fuser, PL 4.15 Item 28.
NOTE: A cold fuser will have a resistance of approximately 46 ohms (220V/240V) or
approximately 14 ohms (110V).
4. Check that there is continuity through the fuser heater and across the over temperature
cut-out.
5. If necessary, install a new ELA HOU - fuser assembly, PL 9.10 Item 4.
6. If necessary, install a new PBA main, PL 1.10 Item 9.
7. If necessary, install a new SMPS + HVPS, PL 1.10 Item 4.
March 2004
2-12
WARNING
WARNING
Work Centre M20 Family