Defective Motor Operation - Samsung SCX-4521F Series Service Manual

6.3.8 Defective motor operation

• Description
Main motor is faulty and paper does not feed into the printer, resulting in Jam 0'
Check and Cause
1. The main motor harness or Motor PCB may be faulty.
6.3.9 No Power
• Description
When system power is turned on the LCD panel does not come on.
Check and Cause
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.
6.3.10 Printed Vertical Lines become curved
• Description
When printing, vertical lines are not straight.
Check and Cause
1. Check stability of 24V supply to LSU.
Samsung Electronics
Solution
1. Check the motor harnesses and connectors, replace
if defective.. If the problem persists replace the main
PBA.
Note Check motor operation using Engine Test Mode.
Solution
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.
Solution
1. 24V stable - Replace LSU.
24V unstable replace SMPS, if the problem persists
replace the main PBA.
Troubleshooting
Service Manual
6-11