Ricoh MP C2504 Field Service Manual page 839

6. Troubleshooting
SC No.
SC547-01
SC547-02
SC547-03
830
Type Error Name/Error Condition/Major Cause/Solution
D Zero cross error (relay-contact soldering)
Zero-cross signal is detected while the fusing relay is OFF.
• Fusing relay defective (contact soldering)
• Fusing relay drive circuit error
1. Reconnect the connectors between PSU (AC controller board) and
paper transport IOB.
2. Replace the PSU (AC controller board).
3. Replace the paper transport IOB.
D Zero cross error (relay contact error)
Zero-cross signal is not detected while the fusing relay is ON.
• Fusing relay damage (contact open)
• Fusing relay drive circuit error
• PSU fuse (24 VS) blowout
1. Reconnect the connectors between PSU (AC controller board) and
Paper transport IOB.
2. Replace the PSU (AC controller board).
3. Replace the paper transport IOB.
4. Replace the harness between PSU (AC controller board) and paper
transport IOB.
D Zero cross error (low-frequency error)
Mains power supply frequency is determined to be 44 Hz or lower.
Frequency instability of mains power supply
1. Check that the mains power supply frequency is higher than 44 Hz.
If it is equal to or lower than 44 Hz, infrastructure may have defects
to be dealt with.
2. Replace the PSU (AC controller board).