Hitachi 8600 no audio :(

Hey,

Got a superbly conditioned 8600 but with no audio Well I say no audio but if I put it on full volume I can hear the radio feintly. Sometimes switching the function switch gives some loud beeps.
I tried with headphones and get the same problem and with batteries the same problem too.
My guess is the amp chip but I'm wondering if anyone has been inside this unit before and knows the amp chip number or can offer any simple advice to isolate.
It looks like it is going to be a real job to get at the chip because of the huge heatsink in there which completely obscures it and getting the board out might be beyond me.
Anyone with this unit knows it ?

Ok, good news !!

Changed the belts on teh deck and we have audio from the deck !!!

I'm now pretty sure it's the function switch that probably needs some lube etc.

Pressing record on the deck and moving the function to Radio, I get a little bit of audio from it and then it goes off. If I don't press anything on the deck and goto Radio I just get either blipping or nothing.

A thorough clean of the tape deck perhaps ?

I've contact cleaned the function switch but perhaps not enough ?