"Markus" wrote in message
...
Greetings,

I have a Yamaha RX-V995 Amplifier that, at any given time, will just
shut off. All I have to do is power it back on and sometimes it will
work for hours and other times it will shut off right away. It would
not hold the last settings and I found the memory cap to be defective,
you know, leaky cap syndrome. That was a 4.7F 5.5V cap. at any rate,
I went over it with a fine tooth comb looking for loose solder joints
and other caps that might be leaky, found and re-soldered a few
cracked joints on a regulator board buried in the bottom of this
beast, all else looks fine. It does have some power relays for the
speaker outputs and B+ power. I remember replacing those on the
fisher amps years ago... I was wondering if anyone has worked on one
of these and what you might of found. This unit is loaded and looks
clean sadly; I do not have a schematic. Nothing leaked into it from
the top. It doesn't appear to have smoked any transistors or
resistors, at least none of the major 'let the smoke out' components.
The power to the proc seems steady and there isn't any noticeable
ripple on any of the power buss lines that I have found. I really
haven't checked for DC showing up on the outputs as of yet, not really
sure how the safety circuits work in this unit. It doesn't run too hot
when on for hours at a time. I thought finding and replacing the 4.7F
cap would have taken care of it, but still shuts down. To reply to me
directly just take caps out of my address.

Thanks in advance,

Markus


The nature of this failure suggests to me that there is a speaker wire
shorting intermittently.

Yamaha's have diagnostics built in that can tell us whether it was an
over-current (shorted speaker wire) situation, a DC offset problem on an amp
channel, a power supply problem, etc.

You may e-mail me direct if you would like some help with this; I am an
authorized Yamaha servicer.

email to:



and reverse the domain name.

Mark Z.