Top Page > Main Chapters > Troubleshooting > Service Calls > SC Tables > SC6xx: Communication Errors
Code
Level
Details
688
D
No CTL_PRREQ_N Signal
Paper failed to feed after the machine has reached the reload temperature, because the main board did not issue a PRREQ signal.
The main board harness connector is loose, broken, or defective.
The main board is defective.
Check the main board harness connector.
Replace the main board.