Faulty S-MASTER amp module in Sony AVD-C70ES???

[Tony]

I just bought an eBay 'fixer-upper' DVD-Player/Receiver that has one
faulty amp channel (out of the 5 x 120watt channels). I'm not familiar
with these amp modules as they are the new-ish S-MASTER module (I think
they're the first generation. They're marked 2X03). I can't even find
anywhere to buy a replacement if I need one.

Symptoms are:

A) the receiver goes into Protect mode when I turn it on and play
anything UNLESS I have the headphones plugged in, presumably because
that takes the amps out of the picture. (Actually it goes into Protect
once the Voltage to the amplifier board rises to about 47V. 50V is
normal).
B) if the headphones are in, then the receiver all works fine BUT the
headphone audio level is quite low.
C) I don't have my scope handy but the resistance across the output
terminals of 4 of the channels rises slowly from about 1M ohm to
infinity (overrange), while the suspect channel stays at about 1M ohm
(or does this mean a shorted cap right at the output?)

Ideas about the fault? Schematics? Service Manual?
Thanks!
Tony

 

[Mark D. Zacharias]

I just bought an eBay 'fixer-upper' DVD-Player/Receiver that has one
faulty amp channel (out of the 5 x 120watt channels). I'm not familiar
with these amp modules as they are the new-ish S-MASTER module (I
think they're the first generation. They're marked 2X03). I can't
even find anywhere to buy a replacement if I need one.

Symptoms are:

A) the receiver goes into Protect mode when I turn it on and play
anything UNLESS I have the headphones plugged in, presumably because
that takes the amps out of the picture. (Actually it goes into Protect
once the Voltage to the amplifier board rises to about 47V. 50V is
normal).
B) if the headphones are in, then the receiver all works fine BUT the
headphone audio level is quite low.
C) I don't have my scope handy but the resistance across the output
terminals of 4 of the channels rises slowly from about 1M ohm to
infinity (overrange), while the suspect channel stays at about 1M ohm
(or does this mean a shorted cap right at the output?)

Ideas about the fault? Schematics? Service Manual?
Thanks!
Tony

Sony has recently restated to all their authorized servicers that they are
not to be distributing any service manuals or bulletins, etc with reference
specifically to distributing them via the internet. I'm not happy about the
situation, and those here on the group know that in the past I've tried to
help out. I can't send you any service literature, but I do think it's safe
to say the amp module itself is bad. You can order it through Andrews
Electronics - though the price may well be prohibitive.

Mark Z.

 

[Tony]

Dang it! Thanks for the quick response Mark. Saved me hours of fun, I'm
sure.

I'll see if I can hot-rod it into a 2-channel by cutting the bad one
out. Say, does anyone need a couple of used S-MASTER amp modules?

Tony

 

[Dani]

That's quite unfair! In my whole province, there are only a few Sony
repair shops.
It's very, very hard to get to be a Sony rep, & the couple of shops
that are reps,
won't help anyone else. Not very good for a customer trying to get some
service.
These shops will have your T.V. for months sometimes, & charge very
high prices.
They don't have any better chance of fixing these units than some of
the other non-
Sony rep shops. Dani.

 

[Jason D.]

Sony has recently restated to all their authorized servicers that they are
not to be distributing any service manuals or bulletins, etc with reference
specifically to distributing them via the internet. I'm not happy about the
situation, and those here on the group know that in the past I've tried to
help out. I can't send you any service literature, but I do think it's safe
to say the amp module itself is bad. You can order it through Andrews
Electronics - though the price may well be prohibitive.

Mark Z.

This will doom the Sony to bad reputation for awhile and their price
is still unreasonable. Sony need to loosen up and deal with
non-authorized service shops as well, not just for Sony's.

Because of this we HAVE to bump up the typical estimate higher by 20%
to 30% even 40% if a fly is involved. This scares customers which is
last thing we wanted. Oh, we're NOT a Sony shop.

Cheers, Wizard