Peavey craps out

Rene Brosseau · From: Chatham,Ontario, Canada

Over the years of owning 4 Nashville 400's, 1 Nashville 100, 2 DPC 750, 2 Nashville 112, & 2 Vegas's, every once & a while, one would crap out...all of a sudden hardly any power, sound breaking up, low volume & a hit with the fist on the top or picking up amp about 4" & dropping it & the problem is solved...Happened last night...hadn't used the amp for over 3 mths, except 30 min here & there...started playing & first song where I pushed the volume & it crapped out. Turned all the knobs. Nope. Thought maybe jack was dirty, but switched to the other jacks, & even when trying the guitar jack, low power, distortion, so a whack on the top & away it went, good for the next 4 hrs. Any one else encounter this ?
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Bob Hoffnar · From: Austin, Tx

Try plugging the effects loop into itself. I had a problem that seems the same as what you are talking about a few months ago and that fixed it until I could get those jacks fixed.
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Carl Kilmer · From: East Central, Illinois

A cold solder joint on the PC board will cause that.
It usually happens on PC board to ground connections.
Carl
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Jim Park · From: Carson City, Nv

About a month ago one of my NV 1000's went up in smoke (literally) during a set. Boy what a stink!!! it started with a loud buzz, then one song later it started smoking, I will be curious to see what went wrong. I'm starting to believe Bobbe, when he says to take spare stuff to the gig, And I'm going to start being more careful loading and unloading my electrical stuff and be more proactive in testing cables, cords and power supplies etc....etc ............BUT in thirty years of playing Peavey stuff this is the FIRST time an amp has quit on stage, and I have been very careless with my amps and its a wonder this hasn't happened before now

Ken Fox · From: Nashville GA USA

Emergency repair for any amp with effects and power amp loops

Bill Terry · From: Bastrop, TX

I've had a ton of Peavey amps of various kinds over the years and I've found the molex connectors that connect the PCBs inside most Peaveys to be a common source of problems.

This is especially likely if 'whacking' the top of the amp creates static or temporarily 'fixes' the problem (although cracked solder joints act the same way sometimes).

Fortunately, it's an easy fix.
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Ken Fox · From: Nashville GA USA

Having modded over three hundred and serviced many more. The most common problems I have seen are the power amp in jack contacts have a high resistance (the jumper is a good temp fix), second is the pre eq in jack followed by the Molex plug used on the early models for a speaker connector. Never yet found a crack on the circuits boards that has caused that, yet that might be a rare instance. Did have one with a small trace crack in the reverb circuit. Also found a lot of busted pots from people not reassembling the chassis correctly and putting excess strain on the pots. Never found a cold solder joint yet. Found a lot of cold joints on early Session 400 amps.

All in all, the N-400 is one of the best built solid state amps I have ever seen, This is the workhorse of the industry. In that same era and built like tanks was the Vegas 400, LA400, Special 130, Specail 140, Bandit 65 and others I am sure were build in that same era. THese amps had a great design for easy service and were just built like tanks!!!

Rene Brosseau · From: Chatham,Ontario, Canada

Thanks for all your responses ! I will keep a short cord with me, but it has been working OK since Saturday
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Tommy Boswell · From: Virginia, USA

My Special 112 does the same thing. A quick spit-clean (better yet, use electronics cleaner) of the loop or power amp jacks usually gets me going. But the problem keeps coming back.

For a permanent fix, do I need to re-solder the jacks?

Ken Fox · From: Nashville GA USA

You need to burnish the contact with a points file or small file, not much as you only need to knock of the crud. Then you can also retension it by first plugging in a cable, then you can apply tension to the contace point to move it closer to the tip section of the plug.

Tommy Boswell · From: Virginia, USA

Thank you, Ken Fox!

Ken Fox · From: Nashville GA USA

In the old day, when I worked as a low voltage electrician in Oregon, I worked on many Rauland Borg school intercoms. The push to talk replay contacts that allow you to listen to the room via the room speaker would often get dirty contacts. I would use a strip of clean white typing paper in between the contacts to clean them up. The idea is not to flatten of the round portion of the contact, so be careful with a file of any sort to just barely scrape that surface area. I pull the file no more than 1/8" in the contact area to avoid flattening the contact. After that I recheck the tension and adjust as stated above. I actually found some NOS auto points files on eBay (almost impossible to buy at an auto ports store for many years now).

Gary Preston · From: Columbus, Ohio, USA

I love the sound i get from my Peavey Nashville 400 's but they have a awful problem with noisy pots !!! Before i play i turn each know back and forth trying to clean or break loose any corrosion or whatever gets in there . Other than that i'm fairly good with them . But lets don't talk about the reverb units on them Mad

Tony Prior · From: Charlotte NC

Thanks again to Ken again for his wisdom and knowledge and to Bob for that great idea with regard to plugging the effects loop into itself.

And yes, cleaning the jacks with spray cleaner can only do so much, as Ken states, burnishing the jacks and connectors is the longer term solution especially for an older amp.

My mid 80's NV400 did the exact same thing about a month back as the thread topic, and this was after I took it apart and pray cleaned all the contacts before the gig, the amp had been sitting for easily a year without use. I knew what the problem was but was not prepared to deal with it on the gig so I used a backup amp. I never thought to use the short jumpers, what a great short term fix.

Since then I have "hard burnished " the jacks, all of them. I am seriously considering replacing them all as well as the reverb molex connector.

I do not want to part with this amp as Ken so correctly states, the N400 is the industry workhorse fro Steel Guitars.

t
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Tony Prior · From: Charlotte NC

Thanks again to Ken for his wisdom and knowledge and to Bob for that great idea with regard to plugging the effects loop into itself.

And yes, cleaning the jacks with spray cleaner can only do so much, as Ken states, burnishing the jacks and connectors is the longer term solution especially for an older amp.

My mid 80's NV400 did the exact same thing about a month back as the thread topic, and this was after I took it apart and spray cleaned all the contacts before the gig, the amp had been sitting for easily a year without use. I knew what the problem was but was not prepared to deal with it on the gig so I used a backup amp. I never thought to use the short jumpers, what a great short term fix.

Since then I have "hard burnished " the jacks, all of them. I am seriously considering replacing them all as well as the reverb molex connector.

I do not want to part with this amp as Ken so correctly states, the N400 is the industry workhorse for Steel Guitars.

t
_________________
Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years

CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website

Ken Fox · From: Nashville GA USA

Tony, even with the new Switchcraft jacks we test everyone for contact resistance and clean or adjust as needed. We have found several as we build amps that needed help! Wish they built them like they used to.

Tony Prior · From: Charlotte NC

Ken Fox · From: Nashville GA USA

I think from sitting in inventory these can just get a bit of oxidation. I can also see some where switchcraft uses a tool to re-align some of the contacts. I found a better method, insert a 1/4 male into the jack and use a small screwdrive against the shaft to push back the contact a bit. That re-aligns it much better.

Tony Prior · From: Charlotte NC

Arty Passes · From: Austin, TX

Rene, I have the EXACT same problem with my 1000. Long story short, after 4 years of being in the shop including 2 trips to Peavey it still has the same problem and is a boat anchor in my practice room.

Randy Wade · From: Batesville, Arkansas, USA

That problem of having to whack the amp on top to get it to work is almost always an effects loop jack/switch giving problems. Ken's emergency fix is probably more reliable than even changing out the jack. Some of the old Tapco boards just had removable jumpers for effects loops, which was a simpler, more trouble free solution I think. Most amps will have two effects loops and either one or both can be the problem. Look for "send" and "return" or "preamp out" and "power amp in".

Arty Passes · From: Austin, TX

That's why it's so frustrating - that was the most obvious and the first thing we checked - and re-checked.

Whip Lashaway · From: Monterey, Tenn, USA

A lot of these Peavey amps have the circuit boards monted upside down. I have fixed more than I can count by simply removing the chasis and reseatting the IC's. They will "talk" to you when you push then into the sockets. Gravity just slowly works them out. Every bump or jiggle loosens them up til eventually it causes problems. The whack on top just wiggles it a little and it starts working again, for awhile. You must be careful when you reseat them Make sure you ground yourself out on the chassis first so static doesn't trash an IC. Just push enough to get the job done. Don't push so hard that you bend the board. I will mension too, like Ken said, on the older one, I have found cold solder joints in the power supply section, usually the caps. In fact, one of the best sounding amps I have was give to me by an old friend. he had replaced it because of a hum. Half hour and half a cent worth of solder and I've used it for years with no problem. i tried to give it back but he wouldn't take it, thank God! Hope this helps. As always, God Bless, Whip.
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Mitch Ellis · From: Collins, Mississippi USA

Ken,
I have a NV400 and as you know, on the front it has pre EQ Patch, "out" and "In". On the back, it has "Pwr Amp In" and "Preamp Out". If I understand you right, I can plug a short cord into the two jacks on the back(Pwr Amp In and Preamp Out) or the two jacks on the front (Pre EQ patch In and Out) and by doing so, it may temporarily fix a problem such as the opening poster had? I know nothing about the electronics of an amp so I just want to make sure that I understand you correctly. Thank you.
Mitch

Ken Fox · From: Nashville GA USA

That is correct!

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