Ricoh G147 Service Manual page 165

The jam counter is reset after a sheet of paper successfully passes the fusing exit
sensor after the cause of the jam has been removed.
Communication timeout error
between BICU and finisher
620 D
The BICU did receive a response
within 100 ms after 3 attempts after
sending data to the finisher.
Communication timeout error
between BICU and finisher
621 D
A break (low) signal was received
from the finisher.
Communication timeout error
between BICU and paper tray unit
623 D
The BICU cannot receive a response
within 100 ms after 3 attempts after
sending data to the paper tray unit.
Communication break error between
BICU and paper tray unit
624 D
The BICU cannot communicate with
SM
Serial line connecting BICU and
finisher unstable
External noise
BICU board and finisher main
board connection defective or
loose
Finisher main board defective
BICU board defective
Serial line connecting BICU and
finisher unstable
External noise
BICU board and finisher main
board connection defective or
loose
Finisher main board defective
BICU board defective
Serial line connecting BICU and
paper tray unit unstable
External noise
BICU board and paper tray
main board connection
defective or loose
Paper tray main board
defective
BICU board defective
Serial line connecting BICU and
paper tray unit unstable
External noise
BICU board and paper tray unit
4-15 G147