Ricoh FT5540 Service Manual page 137

Code #54: Ready Signal Not On
Definition
Lights if the idle signal is not received within 8 minutes after the power relay turns on.
Observation
The fusing lamp does not turn on. The ready beeper does not sound and code #54 is
displayed 8 minutes after power is turned on.
Points to Check
Check the power relay, fusing lamp, ac drive board, and operation panel board.
To control effects of electrical noise from surrounding machines, try JP100.
Check for poor contact in the fusing unit connector.
Code #55: Fusing Overheat
Definition
Lights if the voltage at CN103-4 (fusing thermistor) drops below 0.53 V for 0.4 second.
Observation
The fusing lamp stays on after the temperature rises above 220°C.
Points to Check
Check the voltage at CN504-1 on the ac drive board for line voltage.
Check the resistance of the thermistor.
• Disconnect the white thermistor connector on the front side of the fusing unit.
• Reference value: 1.10 kohms at 180°C 180 kohms at 10°C
2-89
31 August 1989