Samsung SCX-4720F, Руководство по обслуживанию, Страница: 109 / 190

Service Manual
Troubleshooting
7-8
Samsung Electronics
7.2.10 Printed Vertical Lines become curved
• Description
When printing, vertical lines are not straight.
Check and Cause Solution
1. Check stability of 24V supply to LSU. 1. 24V stable - Replace LSU.
24V unstable replace SMPS, if the problem persists
replace the main PBA.
7.2.8 Defective motor operation
• Description
Main motor is faulty and paper does not feed into the printer, resulting in Jam 0'
Check and Cause Solution
1. The main motor harness or Motor PCB may be faulty. 1. Check the motor harnesses and connectors, replace
if defective.. If the problem persists replace the main
PBA.
Note Check motor operation using EDC Mode.
7.2.9 No Power
• Description
When system power is turned on the LCD panel does not come on.
Check and Cause Solution
1. Check if the power input and SMPS output are normal.
2. LCD panel does not come on but normal start up
sounds are heard.
3. After replacing SMPS display does not come on and no
start up sounds are heard.
1. Replace the power supply cord or SMPS. Check
power fuse and SMPS fuses replace if necessary.
2. Replace the OP panel.
3. Replace the main PBA panel.