Right Speaker (STEREO) Goes Out After A Few Minutes

[onplane]

@blhagstrom

Two Connections Pictures
When I went to unplug the pre and main jacks, I noticed when I pulled the one cable out, both speakers came on, and I started playing with combinations and now have found this setup to give me sound from both speakers (Main In RIGHT going to Pre Out LEFT).

So what is going on there, and assuming this permanently fixes it and it wasn't just a "shock" like before, can I keep it set up like this?

What you are doing there is sending the left pre-amp signal to the right power amp. You are getting the left channel played in both speakers, because the right pre-amp is sending no signal at all.

Regards,
Jerry

 

[Kevbo]

What you are doing there is send the left pre-amp signal to the right power amp. You are getting the left channel played in both speakers, because the right pre-amp is sending no signal at all.

Regards,
Jerry

That would explain why it is in MONO then. Thanks! Starting to make sense as you all explain this to me. I truly appreciate it all.

 

[onplane]

@onplane I did notice when things were working fine this morning, when I went to turn the receiver 90 degrees on my table to take those pictures, the signal went out as soon as I moved the unit. Could that also indicate it most likely may be a solder issue?

And your last sentence, I had a little trouble understanding what you meant:

" If have luck diagnosing these using vibration. That is when the right channel goes quiet life the receiver about 2 - 3 inches then drop it to see where the channel comes back. If it does, you need to check all of the solder joints in the right pre-amps."

Actually, as I just pasted your quote in here, I think I see what you are saying. YOU have luck diagnosing these using vibration. So lift my receiver a couple inches and drop it to see if the vibration makes the channel come back on. Well, since it is working right now, I will move it around a bit to see if I LOSE the signal, which I would assume would tell us the same information here. Thanks, Jerry.

~Kevin

Sorry about Android's auto-fix. It usually makes a mess of everything. I've corrected the errors in my original post, but you interpreted correctly.

Kevin, did you pull off that audio cable on the pre-out to main-in? When you do, I suspect you'll lose the right channel.

Regards,
Jerry

PS: You must have a switch somewhere that disables the internal connections between the pre-amps and the power amps. Find it and clean it!

 

[Kevbo]

Sorry about Android's auto-fix. It usually makes a mess of everything. I've corrected the errors in my original post, but you interpreted correctly.

Kevin, did you pull off that audio cable on the pre-output to main-in?

Regards,
Jerry

I did pull it out, yes. I am back to just having the Left and Right AUX plugged in coming off my computer.

 

[WaynerN]

As a past owner of many Marantz receivers, there are 2 big trouble makers at hand. One is all of the tape monitor buttons and such. The low level signal that passes thru these buttons is part of the signal trail. The contacts become oxidized from lack of use, and the signal connection gets lots after the initial on jolt. Spraying and/or working all of the push buttons may "scrap" off the oxidation and restore your troublesome channel.

And last, as blhagstrom mentioned, there is a control relay that engages the speakers after the circuit has stabilized (may be controlled by a resistor) that may have badly oxidized contacts for one side. If this is the case, you can fiddle with everything else until you are blue in the face and it ain't going to get any better.

I put high probabilities that the problem you are having is from this relay. I have fixed several (on in a Sony TA-N55es and one in a Marantz 140 power amp. The initial turn on bang will make the relay contacts let signal thru, but after awhile, the resistance of the contact overwhelms the signal flow and it stops or is at a really low volume.

Wayner

 

[onplane]

I did pull it out, yes. I am back to just having the Left and Right AUX plugged in coming off my computer.

So do you have sound in the right channel? If so, you should have stereo and your balance control should be working properly.

Regards,
Jerry

 

[Kevbo]

So do you have sound in the right channel? If so, you should have stereo and your balance control should be working properly.

Regards,
Jerry

I do have sound in the right channel, and yes, stereo and the balance is working properly. But again, I am currently in one of the "fluke" stages right now of everything working. I'm willing to bet within the hour, I will lose the signal again to the one speaker.

 

[onplane]

I put high probabilities that the problem you are having is from this relay. I have fixed several (on in a Sony TA-N55es and one in a Marantz 140 power amp. The initial turn on bang will make the relay contacts let signal thru, but after awhile, the resistance of the contact overwhelms the signal flow and it stops or is at a really low volume.

Wayner

Wayne, your points about the Tape selector switches are very good and Kevin should work and clean all of these.

As for the relay, we know the signal is lost in the right pre-amp. When Kevin feeds the left pre-amp into the right power amp, he gets sound.

Regards,
Jerry

 

[Kevbo]

As a past owner of many Marantz receivers, there are 2 big trouble makers at hand. One is all of the tape monitor buttons and such. The low level signal that passes thru these buttons is part of the signal trail. The contacts become oxidized from lack of use, and the signal connection gets lots after the initial on jolt. Spraying and/or working all of the push buttons may "scrap" off the oxidation and restore your troublesome channel.

And last, as blhagstrom mentioned, there is a control relay that engages the speakers after the circuit has stabilized (may be controlled by a resistor) that may have badly oxidized contacts for one side. If this is the case, you can fiddle with everything else until you are blue in the face and it ain't going to get any better.

I put high probabilities that the problem you are having is from this relay. I have fixed several (on in a Sony TA-N55es and one in a Marantz 140 power amp. The initial turn on bang will make the relay contacts let signal thru, but after awhile, the resistance of the contact overwhelms the signal flow and it stops or is at a really low volume.

Wayner

I will definitely open it back up to spray around on quite a few of the suggested areas. I probably should have since I had it open, but you live and learn. I'll do it again later tonight after bowling or tomorrow after work. I'll double check the relay, too. I did tap it, but nothing had changed from that.

 

[onplane]

I do have sound in the right channel, and yes, stereo and the balance is working properly. But again, I am currently in one of the "fluke" stages right now of everything working. I'm willing to bet within the hour, I will lose the signal again to the one speaker.

Next time the signal drops out, try that "drop test" to see whether a little vibration brings it back.

In the meantime, as Wayne suggested, work all of those selector switches in particular the Tape monitor switch. Also look for some switch that disconnects the internal pre to power amps and work it as well as clean.

Regards,
Jerry

 

[Kevbo]

Next time the signal drops out, try that "drop test" to see whether a little vibration brings it back.

In the meantime, as Wayne suggested, work all of those selector switches in particular the Tape monitor switch.

Regards,
Jerry

Will do! Thank you @onplane and @WaynerN for that. Oh the fun of figuring all this out! I just want to enjoy my music. haha

 

[blhagstrom]

The speaker relay is GOOD.
It cuts connection to the speakers IF the amp is bad.
Since both amps play (proved by crossing the lines and/or running good signal to each amp through 1/2 wire connection confusion) we an rule out the amps.

Now it MAY be the tape monitor switch. That is the next problem maker in the mix.
Usually bad parts like transistors don't work/no-work. It is possible, but lets get the known easy fixes done first.

When there is no channel working, work the monitor switch a few times, few dozen, hundred.
If that has no effect, then tweak and wiggle all the other controls a bit to see if the channel come back.
If nothing helps, then I think we are down to a transistor on the pre-amp that is doing the "over heat" trick.
It fails once it "warms" up.

If its a pre-amp thing. An o-scope is best, a tech is best. Otherwise its a shotgun repair situation.

 

[WaynerN]

Good luck, all those 22xx series of receiver were pretty nice. They are all getting really old and many, if not all suffer from aliments of one sort or another. It could be something else, but odds are high that its one of these things I have mentioned.

 

[Kevbo]

I will have to get going after this and will hit this back up tonight when I get home, but I just depressed the Tape Monitor button, the one on the right that is labeled SOURCE and Tape. When I pressed that, all sound disappeared (as it should) and it did crackle a little when I pressed it. When I pressed it again, the speaker signal went out. I repeated what I just did, and the signal came back on, again, some crackling when I press and depress that button.

 

[Kevbo]

Now it MAY be the tape monitor switch. That is the next problem maker in the mix.
Usually bad parts like transistors don't work/no-work. It is possible, but lets get the known easy fixes done first.

With what they said, and what you just mentioned, and my pressing the Tape Monitor button, that made the signal disappear and come back on, so I think we may have found the culprit. Does that just needs a good shot of De-Oxit? I will clean all of them tonight, but I should concentrate on that one a little more?

 

[WaynerN]

Does the signal come back on for both channels? If so, push the button in and out about 50 times, that may fix it right there.......

 

[Kevbo]

Does the signal come back on for both channels? If so, push the button in and out about 50 times, that may fix it right there.......

It did come back on, and it also went off if it did it a couple more times, but then it also came back on after another time or two. Alright, I will start pressing it like a mad man and see if signal sticks around longer than an hour, which I won't be able to actually "test" until tomorrow, but I will do the "dirty" work now.

 

[WaynerN]

The speaker relay is GOOD.
It cuts connection to the speakers IF the amp is bad.
Since both amps play (proved by crossing the lines and/or running good signal to each amp through 1/2 wire connection confusion) we an rule out the amps.

Now it MAY be the tape monitor switch. That is the next problem maker in the mix.
Usually bad parts like transistors don't work/no-work. It is possible, but lets get the known easy fixes done first.

When there is no channel working, work the monitor switch a few times, few dozen, hundred.
If that has no effect, then tweak and wiggle all the other controls a bit to see if the channel come back.
If nothing helps, then I think we are down to a transistor on the pre-amp that is doing the "over heat" trick.
It fails once it "warms" up.

If its a pre-amp thing. An o-scope is best, a tech is best. Otherwise its a shotgun repair situation.

You are correct. I didn't read that he got both speakers to run (even if it is mono), so the speaker relay is working (probably could use a cleaning tho).

Wayner

 

[onplane]

I will have to get going after this and will hit this back up tonight when I get home, but I just depressed the Tape Monitor button, the one on the right that is labeled SOURCE and Tape. When I pressed that, all sound disappeared (as it should) and it did crackle a little when I pressed it. When I pressed it again, the speaker signal went out. I repeated what I just did, and the signal came back on, again, some crackling when I press and depress that button.

Like Wayne said, that monitor switch is a good candidate for your problem. Clean it.

Jerry

 

[Kevbo]

Well, if I just wiggle the Tape Monitor button with it OFF (sticking out), I get a crackling sound and the speaker will go off and on as I wiggle the switch around.