[Fred[_12_]]

"Adamfarber" wrote in message ...

'Fred[_12_ Wrote:
;911292']"Adamfarber" wrote in
message ...-

David Nebenzahl;911263 Wrote:-
On 6/13/2010 12:56 PM Adamfarber spake thus:
--
Hi Mark, I unhooked everything and hooked up a speaker to one of
the
outputs and listened to FM and I still heard the him. Thanks,
Adam--

The "him"?
Oh, you must mean the "hymn".


Whoops, meant HUM, thanks, Adam--

Most likely a cap in one of the low voltage supplies has failed,
feeding unfiltered
DC to a regulator which cannot maintain smooth output voltage because
the input
is going to zero 120 times a second.

You have to be a technician with troubleshooting skills, experience
with AV receivers,
test equipment and service information to fix this. Assuming that's
not you, the unit
needs to go to a Yamaha warranty station for repair (Yamaha's warranty
stations have
access not just to service manuals but also to confidential service
bulletins, and more
importantly they have access to the technical staff at Yamaha, which is
the only really
competent technical staff in the business). I can call Allen at
Yamaha, give him the
model number, and he'll tell me what the problem is and how to fix it
because he and his
staff know their equipment that well.

Obviously, I work for a Yamaha warranty station. That's the only
company we still do
warranty audio work for, because it's the only one with a staff that
knows a damn thing
about their product. Well, them and McIntosh, but there are no Mac
dealers around here,
so they don't figure they need a warranty station here (Reno, NV).

Fred


Hey Fred, thanks for the post. I am somewhat handy, if someone could
narrow down which part(s) may be suspect I will replace them so any
help you could give me would be GREAT! Adam

I'll check the service manual & bulletins when I get back to work (I'm out with
the flu at the moment, and don't know for sure when that will be; sometime in
the next day or three) and see if I can give you any worth while advice. Some
models are damn near impossible to take apart and get back together without
the manual. There can be 20 or more cables that have to be unplugged and
then plugged back in to the right socket on the right board on reassembly, just
to get to the board(s) you need to work on. I'm assuming you want to try a
shotgun approach and just replace every cap that could be causing the problem.
It'd take a 'scope to figure out what cap *is* the problem.

Watch this thread; I'll post again when I have some information for you.

Fred


--
Adamfarber