Probably wasted advice. This fellows obviously not a tech; the chances of
him fixing it himself are remote. Probably just too cheap to pay to get it
fixed.
Mark Z.
<pj1108_no_spam_@telus.net> wrote in message
news:(E-Mail Removed)...
> (E-Mail Removed) wrote:
> >
> > Hi,
> >
> > Today I turned on the Sansui 9090 and the flashing red protector light
next to
> > the power button continuously flashed and the stereo never did go on.
The tuner
> > seemed to be picking up signals, as evidenced by the signal meter, but
the
> > sound output meters registered zero and no sound came from the speakers.
Usually
> > the light flashes red for a few seconds, turns green and then the tuner
and
> > stereo activates. Can someone tell me what the cause might be and if
there is a
> > simple fix?
> >
>
> The protector is detecting excessive DC voltage from at least one of the
> power amplifier output stages. It could be a leaky transistor, open
> resistor, etc. on one of the channels or its the protector itself. It's
> not likely that both channels will fail at the same time so your best
> bet is measure for unusually high DC voltage on the relay protector's
> power amp side. Once the faulty channel is isolated you can do voltage
> comparison with the good one but before that check for physical signs,
> see my last paragraph below.
>
> I assume that you've checked for normal power supply voltages. Without a
> schematic, the DC voltage across the big filter capacitors should be
> less but not half the quoted working voltage marking.
>
> With the receiver's age of ~1977, I strongly suggest you to check for
> cold/cracked solder joints on hot spots like diodes, high power
> resistors and transistors. Usually a darkened PCB would indicate hot
> spots. Check for high ESR or dried up capacitors near this area as well.
> Doing this will save you a lot of headaches later on any recurring
> faults.
>
> > I don't have a manual for the unit, and have no idea what the protector
light is
> > for. Can someone tell me where to obtain a manual?
> >
> > Thanks.
> > George
>
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