Cooling spray as a way to find maul function..?

[überfuzz]

I don't have any oscilloscope, but I'm trying to point out a maul function part with an fault that seems to be heat sensitive. (Starts to misbehave after 5 min.) Has anyone tried cooling spray, is it usable in an amplifier?

The idea is the spray different parts to see if the noise in an amplifier goes down, if I were to hit the bad part...

[Jazz P Bass]

Sounds like a plan to me.
On the other side of the coin is a heat source.
Some parts will misbehave when heated.

[Enzo]

That is what chill spray is made for.

[überfuzz]

Mhmm... I guess I'll just go crazy with that spray then.

[Enzo]

Be systematic.

First, it seems you are having something getting noisy after warm up? use the controls to isolate, if you can, to the powr amp or preamp or some section of the amp. No point freezing the preamp if the power amp is noisy.

But once you have narrowed it down, if you can, then pick an area and spray, then move over some. If a quick chill stops the noise for a while, you are onto it. Then by spraying smaller specific areas you can locate the bad part.

Sometimes it can be tricky to not spray a bunch of things. Use a piece of cardboard or a business card as a shield. I can fold a card in a U shape and place it around an IC or something and spray the IC, while blocking the spray from all the parts around it.

[überfuzz]

Ok, I haven't got around to it as of yet.

I have a thread with the noise already. Thread with noisy Twin Reverb. Shortly, the noise seems to come from the "VIBRATO" channel. A lot of thing have been tried...

I'll try the stunt with a credit card, since most of mine are useless.

Thanks!

[Enzo]

"Diagnostic procedure," we don;t use the term stunt. SOunds so cheap that way.

[überfuzz]

Point taken. I'll see if I can establish what is causing the unpleasant sound coming from the amplifier. If I do so, I might prescribe some transplantation of nonfunctional parts.

[Enzo]

Yes, exactly.


I once found a unit with a circuit path interruption due to a failure in a current limiting device, and that was causing a cessation of operation.