SWR up in smoke after turning on.

**BassIsFun17** · #1 03-18-2010, 08:07 AM

Hey guys,

So once again im having a problem with my beloved SWR Bass 750 pre fender. Last night after i came home from practice i decided to play some on my own a little with my SWR. When i turned it on i saw a spark behind the Power switch and then smoke came pouring out. So i freaked out when i saw that and checked both fuses. None of them were blown, both good condition. So i decide to turn on the amp again.....when i turn up the volume to 9 o'clock, which is my usual playing volume. which is plenty loud to jam with a drummer too, it was barely making a sound. it sounded like i had it turned almost all the way down. I have no idea what is wrong with it now. Did i blow some transistors in the power section? or did i mess the preamp up? what could be wrong?

thanks for all help

Infiltration12 · #2 03-18-2010, 08:15 AM

My Sunn 1200s didn't start billowing smoke, but it did have the problem where it wasn't producing any volume. That is a LOUD amp, and when I had it on 10, it was still quiet.

I took it in to an amp tech and he found that many of the internal solder points were really sloppy and the pots were dirty. He touched up the solders and cleans out the pots and it worked as good as new!

Hope this helps!

**BassIsFun17** · #3 03-18-2010, 08:20 AM

okay thanks

yeah i was thinking since i saw a spark, that maybe some solder joints werent fully connected and when it had to spark to get the wires to react with eachother.

toobalicious · #4 03-18-2010, 10:33 AM

hopefully, whatever blew the first time didnt cause anything else to fry when you turned it on again. FWIW, if an electrical device blows smoke upon power up, DONT TURN IT ON AGAIN unless you have a clue what you are doing (or you enjoy watching your equipment catch fire).

i dont mean to be offensive (well, not really), but like duh! or as that popular redneck douche would say, "here is your sign."

Frettage · #5 03-18-2010, 10:41 AM

I don't see how a bad solder joint would cause smoke. Something has likely died.

BassmanPaul · #6 03-18-2010, 12:19 PM

Did the magic smoke come out of the amp or the switch itself??? Could well just need a new switch.

Paul

jsh008 · #7 03-18-2010, 12:26 PM

I'm going to make an educated guess and say that it's part of your power supply section. I see this all the time at work, with computers. I know it's a totally different animal, but the concept should be relevant. The users say there is a spark, then it pours smoke. Nothing else is ever damaged, just the power supply.

Bongolation · #8 03-18-2010, 12:29 PM

This is all idle speculation, but if you saw all that flash and smoke, the location of the problem should be pretty clear once you take the cover off and look.

AltGrendel · #9 03-18-2010, 12:35 PM

Quote:

Originally Posted by Bongolation

This is all idle speculation, but if you saw all that flash and smoke, the location of the problem should be pretty clear once you take the cover off and look.

And if you do this, make sure you unplug the amp first.

In Absentia · #10 03-18-2010, 12:37 PM

Quote:

Originally Posted by AltGrendel

And if you do this, make sure you unplug the amp first.

AND DON'T TOUCH ANYTHING UNLESS YOU KNOW WHAT YOU ARE DOING!

**BassIsFun17** · #11 03-18-2010, 02:24 PM

yeah i am going to open it up this weekend. ill check the power switch area first. otherwise im gonna take it to my tech.