Ricoh D131 Service Manual page 562

Printer ready error
SC964 D
The print ready signal is not generated for more than 17 seconds after
the IPU received the print start signal.

Software defective
Print Start Error
During print processing, another command to start printing was
SC965 B
received.
Software bug
Print image data transfer error
SC984 D
After a data transfer begins from the controller to the engine via the
PCI bus, the transfer does not end within 15 s.

Controller (SIMAC) board defective

BICU defective

BICU/controller disconnected
Scanned image data transmission error
SC985 D
After a data transfer begins from the engine to the controller via the
PCI bus, the transfer does not end within 3 s.

Controller (SIMAC) board defective

BICU defective

BICU/controller disconnected
SM Appendix 2-95
SC900: Miscellaneous
D131/D132/D133