Ricoh FT4227 Manual page 589

COPY QUALITY
2.9 BLACK SPOTS ON THE COPY IMAGE
- Phenomenon -
The grid voltage is not applied correctly.
Poor contact between the charge corona casing
•
and grid plate
High voltage supply board - CTBG defective
•
Main control board defective
•
- Action -
Is there good electrical contact between the charge corona casing and the
grid plate?
Yes No
Repair the poor contact and replace any parts if needed.
Check the voltage at CN103-4 on the main control board.
0 volt Not 0 volt
Replace the main control board.
Replace the high voltage supply board - CTBG.
6-14
12 February 1992