peavey bandit 112 cutting out

[HarryLime]

Hi,

I have a Peavey bandit 112 which after a period of time at rehearsal will start to cut out. The sound cuts in and out at varying rates and between an attenuated volume and the volume I have set. Over the years I've used switch cleaner in all the 1/4" sockets and all the pots which seemed to do the job. I have now bought another amp and left this one gathering dust. I recently fired it up and noticed when I tapped the pre and post gain I can hear the tap through the amp. Also some interference when I touch the casing of the pot. Could it be the Pots need replacing?

Any advice gratefully received.

Thanks.

[Enzo]

First, if the amp has an effects loop, plug a spare cord directly from send to return. If that helps, replace the return jack or service it. Likewise test if ther is a pair of jacks marked preamp out and power amp in.

If that doesn;t help. pull the board and resolder all the controls. And jacks.

Is there a headphones jack with a speaker cutout? Check that.

And if that doesn;t work, apply a signal, connect the chassis to a speaker and start poking with a chopstick, looking for anything that responds to motion.

[HarryLime]

First, if the amp has an effects loop, plug a spare cord directly from send to return. If that helps, replace the return jack or service it. Likewise test if ther is a pair of jacks marked preamp out and power amp in.

If that doesn;t help. pull the board and resolder all the controls. And jacks.

Is there a headphones jack with a speaker cutout? Check that.

And if that doesn;t work, apply a signal, connect the chassis to a speaker and start poking with a chopstick, looking for anything that responds to motion.

Yes in the past I have plugged a spare cord through send and return, also with Preamp and poweramp. which on a few occasions did the job. The last rehearsal I did this had no effect. I'll have a go at resoldering the controls and jacks.

No there is no headphone jack

Thanks.

[Enzo]

You can also, once this happens, plug the guitar into the power amp jack or the effects return jack. Does that also sound weaker than normal? Try it while working OK as a benchmark. This breaks the amp into sections to localize the fault.

[geoff]

Harry,
Did re-soldering the controls and jacks fix the problem? I am having the same problem with my bandit which is about 6 years old now. I have tried plugging a spare lead into the effects loop, but as you said it only works some of the time.

I am a little hesitant to start re-soldering everything without knowing it will fix the problem.

[Enzo]

If a cord plugged from send to return on the FX loop jacks doesn;t cure the problem, then those jacks are probably not at fault. How about the preamp out and power amp in jack pair, did you do the same test there? Either pair of jacks can cause this - or both for that matter.

I would certainly have the board out and resoldering the controls and jacks at this point.

I would be flexing the board and pushing each component with an insulated probe - a wooden chopstick works fine - looking for a sign of an intermittant connection.

Beyond that, you are applying a test signal at the input jack and following it through the amp looking for where it is interrupted.

[HarryLime]

Harry,
Did re-soldering the controls and jacks fix the problem? I am having the same problem with my bandit which is about 6 years old now. I have tried plugging a spare lead into the effects loop, but as you said it only works some of the time.

I am a little hesitant to start re-soldering everything without knowing it will fix the problem.

Hi Geoff,

No I didn't get around to trying this out. I have a different amp now, my friend needed one so I gave him the Bandit for nothing and explained the issue with it. It was a good old trusty amp that kept me going for years. Good luck sorting your problem out.

Harry

[geoff]

Thank you Enzo, I tried plugging a spare lead to the pre amp out and power amp in. I've been playing it for a couple of days since doing so and it seams that this has solved my problem!!

[Enzo]

It will not hurt the amp in any way to run this way as long as you like. However, since that cured it, that means the power amp in jack has an issue.

Squirt some cleaner into that jack then probe a plug in and out a few times. Now see if that woke it up. Otherwise the trouble is either the jack is bad or the solder under the jack has failed.

[MrHockey]

I had the same problem with a very old Bandit 65, which screams BTW.
The problem I found was the push pull bright switches associated with the input volume controls. Get yourself some Radio Shack tuner / lube, and spray it in between the stacked pots. wear some safety glasses and do this outdoors to prevent injury and inhalation from the spray, then work the switch back and forth. I was the USA Yorkville Sound repair tech. in the 70's and 80's.
Chas
Good Luck!