Marantz PM7200 doesn't start after cleaning

[Hronists]

Hello everyone. I would like to get your ideas what went wrong with my amp.

I bought it recently and it was very dirty - all pcb’s were covered with thick layer of dust. I cleaned dust with brush and pcb with spirit and contact cleaner, then cleaned with cotton buds.

After that I switched on and nothing. Some lights went on - power, standby, phono, mute and cd-r. I measured that obviously (because of no relay kicks in) there is no mains to big transformer, switched inputs also have no power. Both fuses on power board are OK.

What would have caused this and what might be at fault?

 

[Lavane]

Any fuses on the back? Also put an ohm meter across the fuses. Sometimes the filament will burn out inside the cap making the fuse look like it's good.

 

[Hronists]

There are 2 fuses, both are good.

 

[Raccoon1400]

So some lights come on but no power to the switched outlets or transformer? That doesn't add up.
You had your meter set on AC not DC when measuring the mains, right?

 

[Hronists]

Of course, meter was set on DC

Also I connected TT to switched outlets - no power.

My main fear is that processor is dead. Is there any way to check it with multimeter?

 

[Raccoon1400]

I suggest starting with inspecting the boards for bad solder joints.

 

[Lavane]

And use a magnifying glass if possible. It may he hard to see cracks around soldering eyes. Heck all wiring also if you haven't. Something may have come loose while cleaning.

 

[Hronists]

to close this thread - it was blown processor on front panel.