Behringer PPA500BT stopped working but lights flickering or blinking

It has been rarely used a little over a year, so it is out of warranty.

If I turned it on, it is not working but all the lights just flickering.

I tried to fix a power board by opening up the back board, but hard to distinguish the power part ‘cause everything is on one board just like you see in the pictures.

It seems this is not an unusual faulty for this specific model.

Any suggestions to test or fix this will be appreciated.