Sony Mutaki Protect Mode

[Tumatauenga]

So I have Sony Mutaki STR-KM7 and after being plugged into a specific power point in the house, we heard a big zap and now when you try to power it on, after a few seconds it goes into protect mode and shuts off (a similar situation has happened with a TV of ours and the same power point  ).

How do I figure out what specifically is causing the issue? I've tried testing all of the IC's and the emitter resistors like the guy in the youtube video I was watching but mine all seem to be fine. What do I do next?

[bingo600]

How old is it ??

I had a STR-DB925 doing a large beep & overload , on most of the "turn on's"
Solved by resoldering all the relay connections inside

/Bingo

[Tumatauenga]

A fair bit Over 5 years old now, I can't see any obvious signs of something being blown or anything like that.