Ricoh D129 - Page 506

Service Call Conditions
SM 6-17 D129/D130
Trouble-
shooting
541 A
Fusing thermistor open (center)
The thermistor (center) detects 0°C or less for 5 sec.
 Fusing thermistor disconnected
 Fusing thermistor connector defective
542 A
Fusing temperature warm-up error(center)
This SC is generated if the following condition occurs:
 The thermistor (center) does not detect an 8°C increment in the fusing
temperature for 1.5 sec. just after the fusing temperature reached 45°C.
 The temperature of the center thermistor does not reach the target
temperature for 28 seconds after the fusing lamps turned on.
 Thermistor warped or broken
543 A
Fusing overheat error 1 (software detection)
A fusing temperature (at the center) of over 230°C (446°F) is detected for 1
second by the fusing thermistors at the center or at either end of the fusing
roller.
 Power supply unit defective
 I/O board (IOB) defective
 BCU defective
 TRIAC short on PSU (PSU defective)
544 A
Fusing overheat error 1 (hardware detection)
A fusing temperature (at the center) over 250°C is detected by the fusing
temperature monitor circuit in the BCU board.
 I/O board (IOB) defective
 BCU defective