Crate Powerblock smokes......fixed it!

[Tone_Terrific]

Maybe releases its smoke is more accurate.
I opened it up and pulled the boards but see nothing that looks toasted.

Smoke came out of the speaker jacks after it started to oscillate with a loud, pulsing, low-freq, motorboating sort of sound.

Anybody familiar with common failures or repairs on these?

[WaltC]

that's not one of the "common" failures that I saw when I was doing Crate/Ampeg repair. Sounds more serious than most, and may not be economical to repair (you can get a working one for under $150 and a comprehensive repair could easily cost over a $100).

[jamesrsmith]

it is toast. buy something else now with your 150 bucks. of course, at my age, i can not understand anyone spending money on repairs for a solid state amp. they are like lap top computers. get a bad one and it lasts for a couple years. a good one can go for many years, like my old carvin acoustic/p a amp. 20 now,,, but if it stopped working, it goes to the dump.

[Peteyvee]

Recycle it as e-waste and buy a nice clean used one.

[wall_of_sleep]

I don't think it's unheard of for these to fail and fixing likely requires skill and care. Sell it for repair.

These posters seem more knowledgeable.
http://www.thegearpage.net/board/sho...d.php?t=657952

[UncleLarry]

Originally Posted by WaltC

that's not one of the "common" failures that I saw when I was doing Crate/Ampeg repair. Sounds more serious than most, and may not be economical to repair (you can get a working one for under $150 and a comprehensive repair could easily cost over a $100).

Yeah, that's the problem with most "budget" gear. The labor to fix it is more than it's worth.

[Peteyvee]

Originally Posted by wall_of_sleep

I don't think it's unheard of for these to fail and fixing likely requires skill and care. Sell it for repair.

These posters seem more knowledgeable.
http://www.thegearpage.net/board/sho...d.php?t=657952

It seems to me that unless the OP is a tech, it would be more economical to just buy another one: http://www.ebay.com/itm/Crate-Power-Block-PowerBlock-Stereo-Guitar-Amp-/261056709754?pt=LH_DefaultDomain_0&hash=item3cc831 447a (no affiliation, just the first one that came up in a quick search)

I doubt anyone is going to pay anything for a smoked Powerblock (I wouldn't, it's a disposable unit) and I seriously doubt that any tech worth his solder is going to fix it for less than $125...

[Tone_Terrific]

I'm trying to fix this for a friend and I can fix anything....if I have the right service info, parts, and lots of time ...I work cheap
Sometimes this forum provides excellent tips

[WaltC]

pm sent

[Peteyvee]

Oh, that's different. Carry on and good luck!

[UncleLarry]

Originally Posted by Tone_Terrific

I'm trying to fix this for a friend and I can fix anything....if I have the right service info, parts, and lots of time ...I work cheap
Sometimes this forum provides excellent tips

That's the ticket! I'm sure Walt will give you good advice!

[Tone_Terrific]

Originally Posted by WaltC

pm sent

Appreciated!

[Tone_Terrific]

I got some service info and found a bad transistor in the power supply section. Replaced it (a very common type) and things settled down.

That was Q2 for those following along the schematic at home

Much of the stuff is surface mount with multiprocessor and IC technology, not friendly to bench work, at all, however it is usually worth a look into this sort of device to catch the more common failures.

[WaltC]

so Q2 huh? Pre-amp or driver, I don't remember?

[Jon C]

there is a reason that these were discontinued based on all I've read (my own is a refurb, meaning it sh!t the bed once itself before being repaired)....