Yamaha receiver sudden death

[JM]

I have a Yamaha RX-350 receiver that suddenly stopped working and produces
no output, either through headphones or the speakers. If I turn the volume
up all the way, I can barely make out the input source in the phones.
Anyone run into this before or have any ideas what a novice multimeter
warrior such as myself might be able to check before getting someone else to
look at it? I've already determined I"m not doing somethings silly like
using the wrong input or having the tape monitor turned on, if that helps!

 

[Andrew Rossmann]

[This followup was posted to sci.electronics.repair and a copy was sent to
the cited author.]

I have a Yamaha RX-350 receiver that suddenly stopped working and produces
no output, either through headphones or the speakers. If I turn the volume
up all the way, I can barely make out the input source in the phones.
Anyone run into this before or have any ideas what a novice multimeter
warrior such as myself might be able to check before getting someone else to
look at it? I've already determined I"m not doing somethings silly like
using the wrong input or having the tape monitor turned on, if that helps!

Have you disconnected EVERYTHING from the receiver? Maybe a cable or
speaker wire is shorting out? Look carefully for any wire hairs on the
speaker wiring posts. You can then try the headphones (are you certain
they are good?) with the tuner. It might help to unplug the receiver for a
few hours, just in case something needs to reset.

 

[JM]

Have you disconnected EVERYTHING from the receiver? Maybe a cable or
speaker wire is shorting out? Look carefully for any wire hairs on the
speaker wiring posts. You can then try the headphones (are you certain
they are good?) with the tuner. It might help to unplug the receiver for a
few hours, just in case something needs to reset.

Nope, tried all that, the phones are good, and everything is unplugged. One
thing I noticed is that it doesn't click when I turn it on any more -- at
first I wasn't sure if it ever did, but after searching Usenet a bit I read
that it should. Could it be that the relay is just stuck in the "off"
position, or is there something preventing it from clicking over into output
mode?

 

[JM]

Nope, tried all that, the phones are good, and everything is unplugged. One
thing I noticed is that it doesn't click when I turn it on any more -- at
first I wasn't sure if it ever did, but after searching Usenet a bit I read
that it should. Could it be that the relay is just stuck in the "off"
position, or is there something preventing it from clicking over into output
mode?

Turns out that's exactly the problem... after desoldering and removing the
output relay, and taking it apart, the coil has actually been broken
somehow... but by physically moving the contacts I got my sound back, so
that must be the problem. I suppose it's possible I severed the coil while
opening the relay, but I was careful while doing it... if I did do that then
the problem must be in the circuit that throws the relay... I guess a tad
more investigation is in order before I go looking for a new part.

 

[JM]

Ok, so after some further testing, it looks like the coil isn't receiving
the 24 volts it needs to throw over to the on position... When I test
between the two sides of the coil, I only get about 3 volts. The odd thing
is, if I test between ground and one side of the coil, I get -40 volts (ie
that side of the coil is below ground). If I test between the other side of
the coil and ground, I get nearly 0 volts.. So I'm a bit confused as to why
I wouldn't then see about -40 between the two sides of the coil.. which
should be more than enough to actuate the coil, I would think.. Any ideas?
This probably all makes perfect sense to a lot of you, but as a novice
tinkerer, I'm stumped

Thanks in advance...


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Remove extra .ns to reply via email
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[Sofie]

JM:
I am a little confused here..... WAS the relay was good or bad BEFORE you
removed it?
Is the protection circuitry providing energizing voltage to the relay?....
or is there DC on the speaker rails thus preventing the relay from being
energized??
I certainly would NOT have a good set of speakers hooked up to the receiver
while you forcibly physically close the relay contacts.... I would suggest
that you should get the proper replacement part installed right away and
continue with your troubleshooting if further repair is required.

 

[Geo]

Ok, so after some further testing, it looks like the coil isn't receiving
the 24 volts it needs to throw over to the on position... When I test
between the two sides of the coil, I only get about 3 volts. The odd thing
is, if I test between ground and one side of the coil, I get -40 volts (ie
that side of the coil is below ground). If I test between the other side of
the coil and ground, I get nearly 0 volts.. So I'm a bit confused as to why
I wouldn't then see about -40 between the two sides of the coil.. which
should be more than enough to actuate the coil, I would think.. Any ideas?
This probably all makes perfect sense to a lot of you, but as a novice
tinkerer, I'm stumped

This looks like you are using a meter without the relay coil in circuit.
In your first measurement the meter is forming part of the circuit instead of
the coil.

Geo

 

[Sofie]

JM:
..... as long is there is enough CURRENT.... try another relay.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------------------------

snipped:

Ok, so after some further testing, it looks like the coil isn't receiving
the 24 volts it needs to throw over to the on position... When I test
is, if I test between ground and one side of the coil, I get -40 volts (ie
that side of the coil is below ground). If I test between the other side of
the coil and ground, I get nearly 0 volts.. So I'm a bit confused as to why
I wouldn't then see about -40 between the two sides of the coil.. which
should be more than enough to actuate the coil, I would think.. Any

ideas?

 

[JM]

Ok, I checked the speaker outs, no DC voltage on either channel, so that's
cool. I'm going to try and get a replacement relay and go from there.. The
particular relay (Omron G5R-2232P) is discontinued from what I can tell so
I'm not sure where to look for a replacement.. I emailed Omron themselves to
see if there is a drop-in replacement directly from them.

Thanks for all the replies so far

 

[Mark D. Zacharias]

You might still be able to get the relay from Yamaha.

Mark Z.

 

[Wdyorchid]

You didn't mentioned if you measured the speaker outputs with the relay
bypassed as someone previously mentioned. I have about the same as you do I
unable to solve it. The problem that won't energize the relay due to a blown
amp. Have you tested your relay outside? It's sounds almost weird to get -40 by
studying this schematic at this webpage. If anyone beleives differently, let me
know how or why. Here take a look.

http://autotails.tripod.com/yamaha.htm

-

 

[JM]

A quick followup: I took the relay to a local electronics parts shop, and
the guy there was able to quickly find a replacement Omron relay for the
G5R -- he gave me a G2R-2 relay which seems to be the same aside from being
dual pole instead of single as in the original. The receiver works fine now
with the new part installed.

 

[jakdedert]

Thanks for the followup. Your experience may help someone else with a
similar problem

jak