Samsung PS50B530S2WXXC Service Manual page 17

■ When the unit is repeatedly turning on and off
Symptom - The SMPS relay is repeatedly turning on and off.
In general, the SMPS relay repeatedly turns on and off by the protection function due to a defect on a board
connected to the SMPS.
- Disconnect all cables from the SMPS, operate the SMPS alone and check if the SMPS works properly and if
Major Checklist each voltage output is correct.
- If the symptom continues even when SMPS is operating alone, replace the SMPS.
- If the symptom is not observed when operating the SMPS alone, find any defective assemblies by
connecting the cables one by one.
Troubleshooting
Procedures
When separating and connecting the cables such as CN800,CN801,CN802,CN803, CN804 of the MAIN
SMPS,CN4005 of the X MAIN Board, and CN5005 of the Y MAIN Board, a spark may be generated by the
Caution
electric charge of the high capacity capacitor. Therefore, wait some time after disconnecting the power cord
from the unit.
Samsung Electronics
1
Check that the Va,Vs voltage of SMPS
①
match the voltages marked on the module
label
Did problem improve?
Did problem improve?
Did problem improve?
Did problem improve?
Did problem improve?
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Troubleshooting
Tune the Va, Vs or Replace the
SMPS
Replace the Main Board
Y Main Board cable check or
Replace the SMPS
X Main Board cable check or
Replace the SMPS
Logic Board cable check or Replace
the SMPS
Replace the X, Y Buffer Board
4-3