Ricoh M0A0 Service Manual page 264

6.Troubleshooting
SC No. Level
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SC No. Level
SC547- D Zero-crossing error (adhered relay contact)
01
When the fusing relay is in an OFF state, a "zero-crossing interrupt request" occurs in 50 ms.
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SC547- D Zero-crossing error (bad relay contact)
02
If a "zero-crossing interrupt request" does not occur in three seconds after the fusing relay is in
an ON state, an error results.
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SC547- D Zero-crossing error (low frequency error)
03
The number of zero-crossing interrupts does not reach a certain value in 500 ms.
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SC No. Level
SC551-00 A Broken fusing (End) thermistor wire
At least ten times, the temperature is detected to stay at -20 degrees C or less for 5 seconds.
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252
Error Name/Error Condition/Major Cause/Solution
Broken fusing lamp wire
The overtemperature prevention mechanism started working
Clear the SP: fusing SC.
Replace the fusing thermistor.
Replace the fusing (Center) lamp.
Error Name/Error Condition/Major Cause/Solution
Damaged fusing relay (adhered contact)
Failure in the fusing relay drive circuit
PSU fuse (24VS) blown
Unstable frequencies at the commercial power supply
Check the commercial power supply.
Replace the fuse.
Replace the PSU.
Damaged fusing relay (open contact)
Failed fusing relay drive circuit
PSU fuse (24VS) blown
Unstable frequencies at the commercial power supply
Check the commercial power supply.
Replace the fuse.
Replace the PSU.
Unstable frequencies at the commercial power supply
Check the commercial power supply.
Replace the PSU.
Error Name/Error Condition/Major Cause/Solution
Broken thermistor wire
Bad connector contact