Amplifier riddle, intermittent loss of output

[Kendrick S]

There are a few threads in the archives on this but I saw no
definitive course of action other than "take it to a repair shop." I
still might do that but that's not really why I'm here.

Onkyo A/V Tuner Amplifier R1 loses output to right channel
intermittently. All the following have occurred:
1. The unit is turned on and there is only output to the left channel.
This is what happens most frequently.

2. The unit is turned on and there is output to both channels.
Everything works, the stereo is a stereo; it happened this morning.

3. The unit is turned on and there is output to both channels and
then the right channel (and once even the left) disappears.

I have swapped the speakers so the problem is not there. There's a
big "click" a second or so after the unit is turned on which I take to
be a speaker protection feature. Is it possible that there is a
problem there? Any suspicions and simple test procedures will be
appreciated.

 

[Bob Shuman]

From your description of the "click", I'd guess that this unit has a speaker
relay that uses a time delay circuit to prevent undesirable power transients
from getting to the speakers. Also your description of the problem could be
explained by resistive relay contacts. Try increasing the volume when you
see one of the speakers dropping out and see if the sound comes back once
you reach the breakdown voltage. You can look at the signal going into the
relay to see if you have a bad contact.

If this is the case, then if you can open the relay you can try to
file/clean the contacts, but in worst case may have to replace the relay.

Good luck and hope this is your cause since it is a fairly straightforward
replacement assuming you can find the replacement part.

Bob

"Kendrick S" <pelicannm@mac.com> wrote in message
news:38ba11bf.0311251311.1e2839c8@posting.google.com...

Onkyo A/V Tuner Amplifier R1 loses output to right channel
intermittently. All the following have occurred:
1. The unit is turned on and there is only output to the left channel.
This is what happens most frequently.

2. The unit is turned on and there is output to both channels.
Everything works, the stereo is a stereo; it happened this morning.

3. The unit is turned on and there is output to both channels and
then the right channel (and once even the left) disappears.

I have swapped the speakers so the problem is not there. There's a
big "click" a second or so after the unit is turned on which I take to
be a speaker protection feature. Is it possible that there is a
problem there? Any suspicions and simple test procedures will be
appreciated.

 

[Jerry G.]

This may be the output stage protection relay, dirty contact in a switch,
cold solder connection, or something similar.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Kendrick S" <pelicannm@mac.com> wrote in message
news:38ba11bf.0311251311.1e2839c8@posting.google.com...
There are a few threads in the archives on this but I saw no
definitive course of action other than "take it to a repair shop." I
still might do that but that's not really why I'm here.

Onkyo A/V Tuner Amplifier R1 loses output to right channel
intermittently. All the following have occurred:
1. The unit is turned on and there is only output to the left channel.
This is what happens most frequently.

2. The unit is turned on and there is output to both channels.
Everything works, the stereo is a stereo; it happened this morning.

3. The unit is turned on and there is output to both channels and
then the right channel (and once even the left) disappears.

I have swapped the speakers so the problem is not there. There's a
big "click" a second or so after the unit is turned on which I take to
be a speaker protection feature. Is it possible that there is a
problem there? Any suspicions and simple test procedures will be
appreciated.

 

[Bob M.]

I had the same problem with my Onkyo receiver and replacing the internal
relay DID cure the problem for several years. But now it has returned again.
Increasing the volume control usually restores the defective channel, and it
is mostly the right channel that quits.

I did however discover that my receiver has a dynamic presence enhancer in
it. What it does is a mystery, but the front panel push-on/push-off switch
is dirty, and causes one or the other channel to cut out as it's pressed in
and out. To get to it I need to disconnect and remove the receiver from my
cabinet and pull the bottom and/or top covers off. I have tried to manually
cycle it a bunch of times but that hasn't helped yet.

I've also had problems with the two speaker pushbutton switches, again dirt.
But what do you expect for a 20+ year old receiver?

Bob M.
======
"Bob Shuman" <reshuman@removethis.lucent.com> wrote in message
news:bq0ie8$kuv@netnews.proxy.lucent.com...

From your description of the "click", I'd guess that this unit has a
speaker
relay that uses a time delay circuit to prevent undesirable power
transients
from getting to the speakers. Also your description of the problem could
be
explained by resistive relay contacts. Try increasing the volume when you
see one of the speakers dropping out and see if the sound comes back once
you reach the breakdown voltage. You can look at the signal going into
the
relay to see if you have a bad contact.

If this is the case, then if you can open the relay you can try to
file/clean the contacts, but in worst case may have to replace the relay.

Good luck and hope this is your cause since it is a fairly straightforward
replacement assuming you can find the replacement part.

Bob

"Kendrick S" <pelicannm@mac.com> wrote in message
news:38ba11bf.0311251311.1e2839c8@posting.google.com...
Onkyo A/V Tuner Amplifier R1 loses output to right channel
intermittently. All the following have occurred:
1. The unit is turned on and there is only output to the left channel.
This is what happens most frequently.

2. The unit is turned on and there is output to both channels.
Everything works, the stereo is a stereo; it happened this morning.

3. The unit is turned on and there is output to both channels and
then the right channel (and once even the left) disappears.

I have swapped the speakers so the problem is not there. There's a
big "click" a second or so after the unit is turned on which I take to
be a speaker protection feature. Is it possible that there is a
problem there? Any suspicions and simple test procedures will be
appreciated.

 

[Mark D. Zacharias]

R1 isn't the model number, it refers to Onkyo's proprietary system remote
feature.
The model number is on the rear panel, should read "TX-something" Like
TX-84, TX-RV47, etc.

A channel cutting out could be almost anything, but those who suggested the
speaker relay may be right, especially if goosing the volume control makes
the sound "punch through" temporarily.
Also, try manipulating the various mechanical controls and switches - you
may find one or more that affect your problem.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Kendrick S" <pelicannm@mac.com> wrote in message
news:38ba11bf.0311251311.1e2839c8@posting.google.com...

There are a few threads in the archives on this but I saw no
definitive course of action other than "take it to a repair shop." I
still might do that but that's not really why I'm here.

Onkyo A/V Tuner Amplifier R1 loses output to right channel
intermittently. All the following have occurred:
1. The unit is turned on and there is only output to the left channel.
This is what happens most frequently.

2. The unit is turned on and there is output to both channels.
Everything works, the stereo is a stereo; it happened this morning.

3. The unit is turned on and there is output to both channels and
then the right channel (and once even the left) disappears.

I have swapped the speakers so the problem is not there. There's a
big "click" a second or so after the unit is turned on which I take to
be a speaker protection feature. Is it possible that there is a
problem there? Any suspicions and simple test procedures will be
appreciated.

 

[Kendrick S]

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message news:<bq21in$1se780$1@ID-180484.news.uni-berlin.de>...

R1 isn't the model number, it refers to Onkyo's proprietary system remote
feature.
The model number is on the rear panel, should read "TX-something" Like
TX-84, TX-RV47, etc.

A channel cutting out could be almost anything, but those who suggested the
speaker relay may be right, especially if goosing the volume control makes
the sound "punch through" temporarily.
Also, try manipulating the various mechanical controls and switches - you
may find one or more that affect your problem.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.

Thanks to all of you; You've given me a lot of confidence that I can
keep the "Oink, Oink" working and postpone going out and buying a nice

new Rotel. But let's see....if I fix it, I can give it to my son when
he heads off to college, and then....

Have a great Thanksgiving,
Kendrick