Ricoh FT7770 Service Manual page 548

30 April, '89
1)
Does the image density change with ID selection?
N
I
Is the development bias applied?
N
Does the bias power pack receive the proper trigger
signal from the main board?
Check for electrical continuity between the rear bias
terminal and the development sleeve. Correct any poor
contact or faulty wiring.
Replace the bias power pack.
Is the toner supply clutch energized?
Y N
I
Does CN301-A6 drop from +24 volts to ground?
Y
Clean or replace the toner supply
Replace the main board.
N
Does CN202-B15 go from ground to +3 volts?
Y N
Replace the main board.
Replace the dc drive board.
clutch.
13-24