Why Unqualified Repairs Are Often Dangerous

[agedhorse]

Is this "see r see" spray?

Any number of products, and yes, even DeOxit D5 if used incorrectly.

 

[sawzalot]

...like you wouldn't notice any of that. SMH

 

[Michedelic]

View attachment 5405553 This came into the shop today, customer first claimed that it was working fine then suddenly stopped working, and of course trying to claim the flat rate service program coverage said that nobody tried to repair it.

Obviously this wasn't the case and it came out that "maybe" he and his "highly qualified" electronics buddy from the local repair shop might have "looked at it" but didn't touch anything other than installing a new tube.

Clearly this wasn't the case, there's a metal rod where the fuse is supposed to be, the jack nuts are missing and the fan wires were cut. There was also "magic cure-all spray" spooge all over the inside of amp (including on the power amp module), which may have been the root cause of the failure.

First of all, this is extremely dangerous because depending on the failure mode, it's possible for the bulk supply caps to explode, which can launch electrolyte onto a person's face and into their eyes (a trip to the ER for sure).

Second, this would have likely been a $100 flat rate repair had they not messed with it. Now, it's in the $450-$500 territory.

This is a good way to learn from somebody else's expensive mistake (or lapse of good judgement), and why I stopped supporting non-factory service except at Fender authorized service centers. I see this stuff more and more these days.

Probably learned their repair technique from some Youtube ‘expert’.

 

[Tassieviking]

Someone just forgot their reading glasses, they thought it said 500 A and not 500mA, you can clearly see where they adjusted it to the correct amps with the sidecutters.
I would like to know which pot shaft he used.
I remember when the store at work ordered the wrong Electra-clean spray in once, one of the electricians decided to spray some into a contactor in a panel while the machine was running, that's when they realized they had the flammable stuff and not the non-flamable spray we normally kept. (I'm surprised that Electrician didn't get a water hose to put the flames out, he was not the sharpest tool in the shed)

 

[Old Blastard]

I've been thinking. All that happened here was a technician trying to resolve a client's issues: The fan was too loud and it kept blowing fuses.

problems fixed!

 

[Hot Rats]

Boy you ain't kidding. My GK400RB is useless after an amp repair guy/friend said he could go through it and clean it up/reduce the hum. Now the power section output is distorted. We still talk but I give him the side eye.

 

[Bassdrifter]

Looks to me like just a "bad" fuse! ;-}

I have a friend that does this on a regular basis. He is an
elevator technician. It is just wrong at so many levels.

 

[Jugghaid]

When Peavey closed up their factory in Mississippi, I bought a pallet of 13 VB2 tube bass amps. They were all marked as factory RMAs (returns) and they had a known fuse issue. I fixed up 11 and kept 2 that I couldn't get running (nor could my tech).

I was laughing at some of the things I saw inside those amps. Obvious that the customers tried their hands at repairs.

Here was one solution to blowing fuses.

Wonder why that failed.......

 

[Jugghaid]

This is some outstanding work with a soldering iron.

 

[bootstrap]

I have a friend that does this on a regular basis. He is an
elevator technician. It is just wrong at so many levels.

Well played.

 

[Hoochie Coochie Man]

That thing in the fuse holder could expedite the repair process. You orient the circuit board with the components facing downward, and power up the amp. The part that is causing the fuse to blow will get hot, and unsolder itself and fall out of the board. That way you know what part to order.

 

[40Hz]

A lot of times in my IT work I’d be called in to fix a flakey Windows server. Most times the problem was relatively minor and no big deal if you knew what you were doing. Windows servers are pretty resilient. They can come down with lingering illnesses. However, they seldom contract a fatal disease.

But occasionally I’d come in and find one that was either seriously borked or completely crowbarred. And every time I got one of those it was always because someone waded in with a software repair tool they didn’t know how to use - or a third party utility they shouldn’t have used in the first place. Some times it’d be bad enough that a complete reinstall from the last full backup was required.

It was the perfect recipe for how to turn a $150 emergency service call into a $1200 charge plus about 4-5 hours of complete downtime for the server. Depending on what function that server performed that downtime could cost the company multiples over what we were charging them due to lost productivity/business.

Those were always annoying calls to get despite being a moderately hefty client check for my company’s coffers. And it was pretty sad considering Microsoft already provides some excellent diagnostic and repair utilities (i.e. DISM and SFC) that, along with a recent product installation disk, can ferret out and repair 99% of any and everything that could possibly have gotten screwed up in one of their operating systems in less than an hour. All you had to know was: (a) that these two tools exist, and (b) how to use them.

I get the feeling amp repairs work the same way.

 

[Timothy Brosnan]

It’s bad enough on solid state amps, but high wattage tube amps could kill you real fast, considering how much voltage those caps can store, even if left unplugged for awhile.

If you don’t know what you’re doing, stay out of the inside of your amp, especially a high powered tube amp.

 

[Major Seven]

That thing in the fuse holder could expedite the repair process. You orient the circuit board with the components facing downward, and power up the amp. The part that is causing the fuse to blow will get hot, and unsolder itself and fall out of the board. That way you know what part to order.

I have met auto mechanics who actually use this approach.

 

[Mark Reccord]

Good God.

 

[40Hz]

That thing in the fuse holder could expedite the repair process. You orient the circuit board with the components facing downward, and power up the amp. The part that is causing the fuse to blow will get hot, and unsolder itself and fall out of the board. That way you know what part to order.

Unless it’s either a fuse or breaker that’s the problem. With those you can save some money and time by just installing a jumper wire in their place. That burning odor you get is what tells you everything’s live once again.

 

[40Hz]

How some “electronic repair techs” envision the inside of a guitar amp:

 

[Jim C]

Here's a question for the group.
Does it seem like more people are apt to thinking they know how to repair a tube guitar / bass head than say their car, TV set, furnace, etc.?
Maybe these folks think that "older technology is easier to work on and really you just need to change the tubes?"

 

[el murdoque]

If it’s a Peavey Mark IV with the metal stuffed in the fuse cylinder that was me in 9th grade.

I was not qualified!

The Peavey Mark IV is meant to be run with a nail jammed in the fuse socket or else it will cut out when you run it with less than 2 ohms load!

 

[agedhorse]

Here's a question for the group.
Does it seem like more people are apt to thinking they know how to repair a tube guitar / bass head that say their car, TV set, furnace, etc.?
Maybe these folks think that "older technology is easier to work on and really you just need to change the tubes?"

Maybe.