Peavey NV112 problem

Tom Johnson · From: Texas, USA

I am having a problem with my NV112. It plays fine with through the headphone jack but not through the speaker. This is an intermittent problem but occurs 80 to 90 percent of the time I try it. I first tried replacing the headphone jack. No help. I took it to an authorized Peavey service provider. The first time I got it back they said they could not reproduce the problem. It worked fine in their shop. I took it home and the problem was still there. I took it back to them, they did some trouble shooting and ended up replacing the head phone jack. Before I left with it the repairman plugged in a guitar and it worked fine. I get it home I have the same problem. Any ideas? Anyone have a schematic of the amp?

Thanks,

Tom

Scott Duckworth · From: Etowah, TN Western Foothills of the Smokies

If you find a schematic, I'd love to have a copy.

Just a thought, since it seems to happen when plugging and unplugging the headphone jack, you might look for a bad solder joint very near the jack. Could be just enough flex to cause it to loose connection.
_________________
Amateur Radio Operator NA4IT (Extra)
http://www.qsl.net/na4it

I may, in fact, be nuts. However, I am screwed onto the right bolt... Jesus!

Tom Johnson · From: Texas, USA

Thanks Scott,

I don't think that would be it. I picked it up yesterday from the repair shop. I had not plugged a headphone into the jack since the shop demonstrated it was playing through the speaker. I simply had moved it. Since it is a solid state amp I don't think the act of moving the amp would cause this problem, but I'm no expert. The jack mounts directly to the pre amp circuit board. It's not like it could be a loose wire or something that simple.

Tom

Carl Kilmer · From: East Central, Illinois

Cold solder joints can give you all kinds of problems.
Just a little change in temperature or a little vibration
can cause a circut to fail, and can be very hard to find.
_________________
aka "Lucky Kay"--Custom built Rittenberry SD10 3X5, Walker S/S, NV-112, and Hilton Pedal

Scott Duckworth · From: Etowah, TN Western Foothills of the Smokies

Even a slight bump can cause a bad solder joint to connect or disconnect. It doesn't take much.
_________________
Amateur Radio Operator NA4IT (Extra)
http://www.qsl.net/na4it

I may, in fact, be nuts. However, I am screwed onto the right bolt... Jesus!

Ken Fox · From: Nashville GA USA

Try to plug a cable from the preamp out to the power Input and see if that solves the problem

Ken Fox · From: Nashville GA USA

Looking at the schematic the preamp in and out jacks are prior to the headphone jack, so disregard that!

Looking a the schematic the headphone jack (J1) does have a contact that closes to the power amp/speaker output path when it is not in use. That goes to a connector (P2). That connector could very well have a cold solder joint under it at the board or a loose wire at the plug on connector. This was a common issue with a similar connector on some of the N1000 amps I have seen in my shop. If a signal can be traced thru those points then the issue is further into the power amp or even a speaker issue as well as a possible speaker connector issue.

Ken Fox · From: Nashville GA USA

Also note that if U2 has gone bad or has an issue around it the speaker output will be dead. The headphone out is driven by U3 and can well be working if U2 is not working. That would cause the very issue you are having as well.

Tom Johnson · From: Texas, USA

Thanks very much for the info. These seems to be beyond my rudimentary skills. The problem is that the repair shop is happy that it played ok in their shop...I will try to find another shop that may be interested in actually solving the problem.

Regards,

Tom

Ken Fox · From: Nashville GA USA

The small cost to ship the chassis to Peavey would be well worth it for a properly repaired amp. Just a thought

Tom Johnson · From: Texas, USA

Thanks Ken,

I will call them and check into it.

Tom

Carl Kilmer · From: East Central, Illinois

Before you send it out, you should try another speaker
if you have one. I had one that would only work for a
few minutes and then quit. The voice coil had opened.
_________________
aka "Lucky Kay"--Custom built Rittenberry SD10 3X5, Walker S/S, NV-112, and Hilton Pedal

Tom Johnson · From: Texas, USA

Thanks,

This one is not working at all, most of the time. When the speaker works you can play through it and no issues. When I first had the problem it occurred after I had been using the headphones. I should add this amp is not old. I am the second owner so no warranty. It was purchased new in November 2012. The first owner said he did not play it much, and I have played it maybe
20 hours (mostly through the headphones).

Thanks,

Tom

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