In lg studioworks 500g one capacitor blo...

Before you open it test the input use analog multimeter for continuity testing,
if the pointer moves forward then turns back quickly your rectifier diode is good but the pointer is steady like this image below

Note:
Make sure this power cord connected to
your monitor before testing.
you have shorted semiconductor inside. check the thermistor, the bridge type diode & relay switch can cause of blown filter capacitor if you did not found these shorted at the primary section of power supply.

Gud luck..