Sony TA-AV670 amp repair

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Hello all, I'm pretty new to the electronic side of amps although am prepared to search, learn and listen. I've just got a Sony TA-AV670 to work on (I had actual bought it for parts but it seems like a good unit so I'll have a crack at repairing it).

Amp:
http://www.bikihifi.hu/sony_ta-av670.htm
If anyone has any form of manual they could copy to me that would be much appreciated 🙂 .
It is all very modular which should help a fair amount.

Problem 1:
Dropped on end and wouldn't power up.

Solution 1:
I've removed and repaired the AC power board (where there was a relay and small transformer, to turn it on). The board had cracked under the force from the small transformer.
The unit then turned on including lights and display. All of the input selections etc work.

Problem 2:
There is no ouput from the speaker outputs apart from what sounds like a damped tone (like the noise you get from a metal detector when it passes over a metal obtect) it lasts about 2seconds in which time it goes from a certain volume, damping to nothing. The tone sounds whenever the source is changed (a button pressed) or when the volume is changed when it is over 50%.

Solution 2:
I've had a look around although nothing looks damaged, I stupidly haven't got a suitable resistor to discharge the capacitors until Monday so can't really have a proper crack.
Have you guys got any idea what the problem could be, from your experience?

Thanks a lot for reading ^^ 🙂 .
 
I've had a good look around in this now and there doesn't appear to be any physical damage so I'm going to have to get down and dirty with it I guess. I still can't locate the manual so I suppose I'm going to have to buy it 🙁 .

One query I have though; the amp does not have any form of earth lead? The power lead it just a live and neutral. Is this right? It seems very dangerous bearing in mind the chassis is all metal.
There is a screw terminal on the back labelled earth however I presume this is for linking equipment, rather than literally connecitng to ground??

Cheers
 
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