Power Supply Related Malfunctions; Main Relay Ry1 Is Not Turned On - Minolta CF910 Service Manual

3-3.

Power Supply Related Malfunctions

(1) Main Relay RY1 is Not Turned ON

• Noise Filter FLT1
• DC Power Supply 1 PU1
<Troubleshooting Procedure>
Step
1 Is the voltage across PJ1L-1 and -2 on
PWB-L and GND DC24V?
2 Is CB1 open?
3 Is the power source voltage being applied
to PU1?
4 Is the voltage across PJ5PU1-1 on PU1
and GND, and across PJ5PU1-2 and
GND DC24V?
5 Do RY1L and RY2L operate when S1 is
turned ON?
6 Is the voltage across PJ10I-6A on PWB-I
and GND DC24V?
Possible Defective Components
Check Item
T-52
• Power Supply Board PWB-L
• Main Relay RY1
• Master Board PWB-I
Result
NO Check the harness between
PWB-L and PG1.
YES Check that there is no short-cir-
cuit in the power line (white/
black wire), then close CB1.
NO Change FLT1.
NO Change PU2.
NO Check the continuity across
PWB-L and S1 and, if there is
conduction, change PWB-L and
S1, in that order.
NO Check the harness between
PWB-I and PWB-L and PU2
and RY1 for possible breaks.
1154C21TAA
Action