Ricoh B121 - Page 147

SERVICE CALL CONDITIONS
SM 4-5 B121 Series/B259 Series
Trouble-
shooting
No.
Definition
Symptom Possible Cause
Paper feed motor lock (optional paper tray units) 506 C
A motor lock signal is not detected for
more than 1.5 s or the lock signal is not
detected for more than 1.0 s during
rotation.
• Paper feed motor defective
• Too much load on the drive
mechanism
Fusing thermistor open (center) 541 A
The fusing temperature detected by the
thermistor is below 71°C and is not
corrected after the main power switch is
turned on.
• Fusing thermistor defective or out of
position
• Power supply board defective
• Loose connectors
Fusing temperature warm-up error (center) 542 A
The fusing temperature rises less than
7 degrees in 2 seconds, and this
continues 5 times consecutively.
The fusing temperature is not detected
in 25 or 35 seconds.
• Fusing thermistor defective or out of
position
• Fusing lamp open
• Power supply board defective
Fusing overheat error (center) 543 A
The fusing temperature is over 230°C
for 1 second (detected by the
thermistor).
• Fusing thermistor defective
• Power supply board defective
Fusing overheat error (center) 2 544 A
The fusing temperature is over 250°C
for 1 second (detected by the fusing
temperature monitor circuit).
• Fusing thermistor defective
• Power supply board defective
Fusing lamp overheat error (center) 545 A
After the fusing temperature reaches
the target temperature, the fusing lamp
does not turn off for 12 consecutive
seconds.
• Fusing thermistor defective or out of
position
• Power supply board defective
Unstable fusing temperature (center) 546 A
The fusing temperature varies 50°C or
more within 1 second, and this occurs 2
consecutive times.
• Thermistor defective or out of
position
• Power supply unit defective
Zero cross signal malfunction 547 B
Zero cross signals are not detected
within 5 seconds after the main power
switch is turned on, or are not detected
within 1 second after operation begins.
• Power supply board defective
• BICU defective
Fusing thermistor open (rear) 551 A
The fusing temperature detected by the
thermistor is below 71°C and is not
corrected after the main power switch is
turned on.
• Fusing thermistor defective or out of
position
• Power supply board defective
• Loose connectors
Fusing temperature warm-up error (rear) 552 A
The fusing temperature rises less than
7 degrees in 2 seconds, and this
continues 5 times consecutively.
The fusing temperature is not detected
in 25 or 35 seconds.
• Fusing thermistor defective or out of
position
• Fusing lamp open
• Power supply board defective