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I'm stumped Denon AVR 1804 resets after 10 minutes please look

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zorbzz

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Hi guys Ive had this Denon for a few months now trying to fix it. I have limited time so its taking forever it seems.
If anyone could steer me in the right direction it would be greatly appreciated.

A rundown of whats happened so far.
A good friend bought this amp new and has his home system setup with it, when it failed he simply asked me if I wanted to fiddle around with it and see if I could fix it, knowing I am no expert but can fix basic things.

First thing I done was replace the regulators.
Still wouldnt start so I tested all of the output transistors to find 2 channels blown.
Replaced those but still wouldnt start, it actually blew a fuse then.
I then took the main board out and started checking components.
On the blown channels there were some blown output resistors .22 ohms and bad caps some open some way out of spec.
Replaced all of the components on the main board that I could test as bad (my capacitance meter only reads up to 100 uf) which ended up being:
+ and - 15 volt regulators
.22 ohm emitter resistors
caps out of spec on the output channels.
HEAPS of bad solder joints on the mainboard.

The reciever turned on HOW HAPPY I WAS...
I measured the temps of the regulators at 37 celcius each, tuned it to a fm channel and listened through a speaker.
About 10 mins later a relay click and it turned off but restarted,.
When it restarted it nearly instantly clicked and restarted again.
Then kept doing that till it cooled down again.
It lasts around 10 mins till it will click and reset from a cold start.

Any advice on where I should go now?
Thanks heaps.
 
Check the ESR on all the capacitors. Often they dry out and weird things start happening.

If they are ok, grab a service manual and run through any checks and tests listed in that.
 
Thanks but I dont have an esr meter.
It works perfect now but resets after 10 mins do you think a cap can cause this?
 
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