New english member

Hey guys, just dropping a line to say hi'

I have been in to car audio sine the mid 90's and have worked in the industry,

I will be needing some advice on a repair of an Alpine MRV1507 where is the best place to start the thread? It does not even power up no lights at all.

Ive taken the cover off and it looks like It has never been used the terminal screws have never been tightened down.
Zero dust on the fan. All components seem intact.

I've bench tested it and the capacitors charge' I've followed the 12v in to the circuit board a little way but that is as far as I have got. Can some one point me in the correct direction thanks,