: Check the SR360 or similar Schottky diodes on the secondary side. If the receiver is completely dead, these are likely shorted.

The power supply block (PSU) generally follows this architecture:

: Usually 33–47µF / 400V; a common culprit for failure if it bulges.

: The most frequent issue. Even if they aren't bulging, capacitors like the

on the output lines often dry out, causing the receiver to "boot loop" or fail to turn on.

: The "heart" of the unit that manages switching.

: If the output voltages are unstable or "pulsing," the feedback loop involving the optocoupler may be faulty. Critical Voltages to Check