Amp issue

[CrackedPepper]

I have an "old" Peavey Revolution 112 amp.  I made the mistake of plugging into an electrical outlet that had an "open hot" connection.  Now the amp will not produce any sound even though it appears to be powering up.  The nearest Peavey amp repair place is several hours from me and the amp is pretty heavy so shipping will be pricey (and I am a cheapskate).  Any advice on how to troubleshoot this thing?

 

[Cagey]

What's an "open hot" connection?

I can think of several ways to wire an outlet wrong, and I think I have them all covered, but I can't imagine any one of them causing an amp to suffer. Might make you suffer, but that's another discussion.

If the amp appears to power up, chances are the fuse is good, so chances are the output stage is blown. Solid state amps are pretty fragile in that area, especially the older designs, and especially older Peaveys. That's largely where they lost all credibility in the market. Their older solid state amps were easy to blow up, and even when they worked they sounded like horse puckey. It's too bad because Peavey makes some nice stuff now, but they've never been forgiven for that older stuff.

 

[Paul-less]

If the "hot" was "open", the circuit (fuse in older buildings, not up to code [ILLEGAL]) would have switched, and you would have no electricity.

Want to explain "hot open?"

 

[Cagey]

If the "hot" was "open", the circuit (fuse in older buildings, not up to code [ILLEGAL]) would have switched, and you would have no electricity.

Want to explain "hot open?"

The fuse or breaker wouldn't open if the "hot" or the neutral/ground was open, because there'd be no way to draw any current. And if they were wired backwards, the amp would still work, but his guitar would be hot relative to other gear. That's why I'm confused, too.

I have a feeling his amp just went tits-up, and it's a coincidence that he managed to plug it in somewhere else when it happened.

 

[Paul-less]

If the hot was open and touched anything grounded, there would have been a short and the circuit would have flipped.

But yes, I agree with you.

 

[-CB-]

Hehehe... I thought hots were s'posed to be open.  Think of it, whats the alternative.... a shorted hot?  Now that wouldn't do at all.  Hots is open till you plug in, right?  The equipment completes the circuit.  But I digress!

Thinking more... in some places they run 200 and 220/240, bi-phased, and you can have an open hot, and damage things if the equipment references ground/neutral.

Peavey amps are noted for having speakers go wonky.  Check the speaker itself with a 9v battery.  The battery should deflect the cone a decent amount.

After that... get out your soldering iron.  Peavey has one of the best customer service departments I've ever dealt with.  You can call them, and they'll sell you the suggested parts (after some brief discussion) and the prices are really low.  I rebuilt my bosses kids amp - a few op amps and two big transistors, for like under six bux from Peavey.  Try that route perhaps.  Also, you can pull the chassis from the cabinet and send that over to them in Mississippi, for 1st class repair.

 

[exaN]

Hehehe... I thought hots were s'posed to be open.  Think of it, whats the alternative.... a shorted hot?  Now that wouldn't do at all.  Hots is open till you plug in, right?  The equipment completes the circuit.  But I digress!

Thinking more... in some places they run 200 and 220/240, bi-phased, and you can have an open hot, and damage things if the equipment references ground/neutral.

Peavey amps are noted for having speakers go wonky.  Check the speaker itself with a 9v battery.  The battery should deflect the cone a decent amount.

After that... get out your soldering iron.  Peavey has one of the best customer service departments I've ever dealt with.  You can call them, and they'll sell you the suggested parts (after some brief discussion) and the prices are really low.  I rebuilt my bosses kids amp - a few op amps and two big transistors, for like under six bux from Peavey.  Try that route perhaps.   Also, you can pull the chassis from the cabinet and send that over to them in Mississippi, for 1st class repair.

Damn I wish I knew as much about electricity as you haha ccasion14:

 

[CrackedPepper]

Okay - here's what I know about what happened.  I tested the outlet that the amp was plugged into after it konked out.  I used an outlet polarity tester (see pic below) and it lists the terms you guys are bandying about (open hot, open neutral, etc.) I can tell you that we had a shitety home inspector when we bought the house (many many problems were missed - that's another story) so it's no surprise to me that this outlet does not meet code.  No grounds, no shorts, no tripped circuits - I just reported what the tester indicated as a possible contributing factor.  

So what I am getting out of this is what Cagey stated, it's probably just a coincidence that the amp crapped out and the outlet had nothing to do with it.  I'll perform the 9v battery test and see if it's the speaker as CB recommended.

Thanks to everyone for their help and input.

 

 

[Paul-less]

Hehehe... I thought hots were s'posed to be open.  Think of it, whats the alternative.... a shorted hot?  Now that wouldn't do at all.  Hots is open till you plug in, right?  The equipment completes the circuit.  But I digress!

Thinking more... in some places they run 200 and 220/240, bi-phased, and you can have an open hot, and damage things if the equipment references ground/neutral.

Peavey amps are noted for having speakers go wonky.  Check the speaker itself with a 9v battery.  The battery should deflect the cone a decent amount.

After that... get out your soldering iron.  Peavey has one of the best customer service departments I've ever dealt with.  You can call them, and they'll sell you the suggested parts (after some brief discussion) and the prices are really low.  I rebuilt my bosses kids amp - a few op amps and two big transistors, for like under six bux from Peavey.  Try that route perhaps.   Also, you can pull the chassis from the cabinet and send that over to them in Mississippi, for 1st class repair.

I'm sorry, I ment "unshielded" by open. Recently some dumbass I let borrow my guitar put in his own puppies for a show, then put mine back in afterwards. However, he wired everything backassward and my braidedground was used as the hot.

 

[Super Turbo Deluxe Custom]

I have one of those circuit analysers.  If I recall correctly, "Open Hot" lights up nothing.  In other words the hot isn't there, it's open, the plug is dead.  Those can be handy, but unless there's a hot/neutral reverse (the most common mis-wire - but with AC power still works)  or open ground, they're used more to confirm that something is wired correctly than diagnose problems.

 

[-CB-]

I have one of those circuit analysers.  If I recall correctly, "Open Hot" lights up nothing.  In other words the hot isn't there, it's open, the plug is dead.  Those can be handy, but unless there's a hot/neutral reverse (the most common mis-wire - but with AC power still works)  or open ground, they're used more to confirm that something is wired correctly than diagnose problems.

The tester shows open hot, but the amp still turns on.  Now THAT is strange.  Tester bad?  Test it someplace known to be good.

 

[CrackedPepper]

Yep - the tester was bad.  Borrowed a friends and bought a new one - they both read "open ground".  Does that help explain the blowout?

Also got a 9 volt battery to test the speaker and it moved the cone.  I'll call Peavey tomorrow and see what they think...

 

[Cagey]

The tester shows open hot, but the amp still turns on.  Now THAT is strange.  Tester bad?  Test it someplace known to be good.

It's possible. If the outlet is wired backwards, then the neutral is hot and the hot could be either open or grounded, but the neutral would still measure 120vac to ground. So, it would power up, but the chassis and anything supposedly grounded would be hot relative to any other equipment that was plugged into an outlet that was wired properly. The P.A., for instance. That's where you grab your guitar's neck, cozy up to the mike, and get knocked on your ass because the potential between you and the mike is 120vac. Kinda makes your lips tingle - hard <grin>

 

[Super Turbo Deluxe Custom]

Most likely this is an older, 2 wire house that has been retrofitted with a 3 wire receptacle and ground left terminated to nothing.  And yes, a hot/neutral reverse will knock you on your butt if used in coordination with other components that are wired correctly.

 

[Cagey]

... And yes, a hot/neutral reverse will knock you on your butt if used in coordination with other components that are wired correctly.

Or, if you're standing on good ground - like a concrete floor - without rubber-soled shoes on. Back when I was a kid and they'd first invented electricity, those damnable Fender amps were a great source of amusement if you were a bit masochistic. We didn't know why back then, but apparently Leo's crew did, and put "polarity" switches on the amps to ruin everybody's fun. Not to poke at Fender; few places had grounded outlets back then, so there was no good way to enforce polarity on anything.

 

[AprioriMark]

Back when I was a kid and they'd first invented electricity,

OMFG, hahaha

-Mark

 

[-CB-]

if you had an open ground.... that shouldn't be a problem

if the ground was open and the hot and neutral were reversed.... still no problem, as there is no reference to ground and you still have 120v from hot to neutral

if the hot and neutral were reversed AND the ground was also present, that would be a problem, as the chassis would be "hot" and you'd have some issues, possibly blowing solid state stuff.

Check for internal fuses