Kyocera KM-2550 Service Manual page 157

(1) No image appears (entirely white). Causes
Causes
1. No transfer charging.
A. The connector terminals of the high-volt-
age PCB make poor contact.
B. Defective engine PCB.
C. Defective high-voltage PCB.
2. No LSU laser is output.
A. Defective laser scanner unit.
B. Defective main PCB.
3. No developing bias is output.
A. The connector terminals of the high-volt-
age PCB make poor contact.
B. Defective engine PCB.
C. Defective high-voltage PCB.
(2) No image appears (entirely black). Causes
Causes
1. No main charging.
A. Broken main charger wire.
B. Leaking main charger housing.
C. The connector terminals of the high-volt-
age PCB make poor contact.
D. Defective engine PCB.
E. Defective high-voltage PCB.
2. Exposure lamp fails to light.
A. The connector terminals of the exposure
lamp make poor contact.
B. Defective inverter PCB.
C. Defective engine PCB.
1. No transfer charging.
2. No LSU laser is output.
3. No developing bias is output.
Check procedures/corrective measures
Reinsert the connector. Also check for continuity within the connector
cable. If none, remedy or replace the cable.
Replace the engine PCB and check for correct operation.
Replace the high voltage PCB and check for correct operation.
Replace the laser scanner unit (see page 1-6-29).
Replace the main PCB and check for correct operation.
Reinsert the connector. Also check for continuity within the connector
cable. If none, remedy or replace the cable.
Replace the engine PCB and check for correct operation.
Replace the high voltage PCB and check for correct operation.
1. No main charging.
2. Exposure lamp fails to light.
Check procedures/corrective measures
Replace the main charger unit (see page 1-6-40).
Clean the main charger wire, grid and shield.
Reinsert the connector. Also check for continuity within the connector
cable. If none, remedy or replace the cable.
Check if YC9-5 on the engine PCB goes low when maintenance item
U100 is run. If not, replace the engine PCB.
Check if main charging takes place when YC1-12 on the high-voltage
PCB goes low while maintenance item U100 is run. If not, replace the
high-voltage PCB.
Reinsert the connector. Also check for continuity within the connector
cable. If none, remedy or replace the cable.
Check if the exposure lamp lights when YC1-1 and 1-6 on the inverter
PCB go low while maintenance item U061 is run. If not, replace the
inverter PCB.
Check if YC17-1 and YC17-6 on the engine PCB goes low when mainte-
nance item U061 is run. If not, replace the engine PCB.
2FT
1-5-27