Thread: NAD T762 fault
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Jamie Jamie is offline
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Default NAD T762 fault

Torben Espoe wrote:

Hi
I have recently tried to repair a T762, not very succesfull I'm afraid.
The story is this: I was listening to music one day and suddenly the amp
shuts down with at loud POP in the speakers and red light in the status led.
I turn it off and then on again and now there is nothing coming out of the
speakers, other than hum when I turn the volume up to max. After some
checking I find that it can still switch between video feeds and the main
amps still work if I use direct input.
After some seaching in the schematics I'm guessing that it has to do with a
missing voltage, and sure enough the +12V is missing. After half an hour of
disassembling I have the motherboard out, and I measure the 5V1 zeners and
one is dead. I exchange all 5V1 zeners with 5W types an reassemble the amp,
but now it will not turn on.
The status light is amber, but no turn on. I measure the power on +13V and
find it about 6,5V at D712. it seems that some thing on the +5,6V is drawing
to much current for the poweron trafo.

Does anybody have any sugestions?

Torben

email exchange TWO with 2



check some electrolytic caps for shorts.


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