Ricoh FT7770 Service Manual page 564

30 April, '89
I
Does the input voltage on the main board (CN208-B20) go
from LOW to HIGH (+12 volts)?
Y N
Check and correct the harness and/or connector.
Replace the main board.
o Turn the main switch off
o Disconnect CN228 on the lamp regulator.
o Turn the main switch on.
If the exposure lamps light replace the lamp regulator.