Perhaps this from OHM Supply can help:
(Looking for a repairkit can often show the defective components, but ??)
A 9 piece repair kit.
Board Number:
•YPSUU-J011A REV 1 PSU (2300KEG002A-F)
Used In:
•LG 42PC1DV
Fault symptom:
•DEAD
•SLOW TO COME ON
Whats in the KIT:
•C201
•C202
•C203
•C227
•C271
•C272
•C281
•C282
•