very OT: electronic equipment can go wrong

paul_w wrote on 1/17/2012, 7:21 AM
This is what happens when power amplifers get abused in clubs. Cleaning the fans and foam filters always get neglected. This is what i saw as my first job this morning on my bench with a note: fault.... burning.
Amp Fire

be carefull out there... could have burned the building down.

Paul.

Comments

john_dennis wrote on 1/17/2012, 7:29 AM
I'll see yours and raise you one. They don't even have to be abused. They can be well maintained and still fail.

paul_w wrote on 1/17/2012, 7:32 AM
Oh yeah - nice, what no fire extinguisher?

Paul.
farss wrote on 1/17/2012, 7:53 AM
That's not a switch, this here is a switch.



That's one of three on the output of a 500MW generator, you don't want to be in the room when that thing operates. Capable of switching 24KV at 85KA.

Bob.
paul_w wrote on 1/17/2012, 7:59 AM
That guy looks like he's running for his life!

Paul.
john_dennis wrote on 1/17/2012, 8:01 AM
We're up to 500MW. Do I here a GW? This cold war is escalating fast.
musicvid10 wrote on 1/17/2012, 8:35 AM
Only 500 MW? Looks too noisy for my shows anyway. J
john_dennis wrote on 1/17/2012, 9:14 AM
"That guy looks like he's running for his life!"

I thought I was. Moving away form the blast was a knee-jerk reaction.
paul_w wrote on 1/17/2012, 9:16 AM
John, was talking about Bobs post. Is that you in the UPS fail video? blimey.

Paul.
john_dennis wrote on 1/17/2012, 9:23 AM
Yes. Not the first time for such an event. I'm getting too old for this stuff.
johnmeyer wrote on 1/17/2012, 11:11 AM
A good friend, many years ago, gave me his exotic power amp to fix. He had decided to re-wire the speakers while the amp was turned on !!! Not only did it create a nice scorch mark on the PCB, but it unfortunately took out too many components to count. I purchased a bunch of transistors to replace those that tested bad, but after several hours on the bench, I finally gave up.

Hopefully you'll be able to just replace the driver transistors and get it running again.
paul_w wrote on 1/17/2012, 11:34 AM
Its gone right through. The fire was more power supply related but once it took hold the damage blew output transistors, drivers and the power supply itself.. Its a write off. The amont of time needed to repair this would cost more than a replacement amp. Its a Peavey 1800, not expensive. What you cannot see is the other side of the PCB, no kidding, its fire damaged inside and out.
Re-wiring the amp while its still on? ... brave.. but not a great idea.

Paul.
farss wrote on 1/17/2012, 3:02 PM
"Yes. Not the first time for such an event. I'm getting too old for this stuff. "

You really should be wearing safety gear when you're working around that kind of gear that's live. Facemask, apron and gloves.

Bob.
Chienworks wrote on 1/17/2012, 3:13 PM
I had an old eMachines PC being used as an email server that lost its fans one night. The CPUs got hot enough before thermal shutdown to melt all the solder in about a 2" radius around the chips. When i opened up the case in the morning i found chips and capacitors in a puddle of rehardened solder on the bottom. The electronics techs told me the type of solder used melts at 720F/380C. I'm amazed nothing caught fire.

Some friends called me up once to take a look at their stereo. They had been having dinner when the music suddenly stopped. When they turned around to look at it they saw a huge cloud of white, evil smelling dust spewing out of it. They figured it was a complete goner. Of course, all that had happened was one of the 55 year old electrolytic power caps had burst. I replaced all 6 with new ones just to be safe. Grand total repair cost: $2.95 + maybe 20 minutes free labor (well, they fed me dinner too). I wonder if it will last another 55 years?