oil problem

[woodyc]

I've had a bunch of repairs where the chassis has a lot of oil and sticky dust inside. Here's a board from one I fixed last week...



Usually the power stage overheats and shorts from all the oil/dust buildup. But the oil also gets into screw threads and anything without a lock washer loosens up. One time I found a screw stuck in a fan, and another time one was shorting a hv supply. I'm guessing it may be mineral oil from a smoke machine? It comes off pretty easily with isopropyl and compressed air. Anybody else seen this?

[52 Bill]

I usually see that in fan ventilated power amps that sit in restaurants near the kitchens. The grease in the air gets sucked in and builds up like that. Sometimes it will smell like kitchen grease.

[soundguruman]

Basically, dirt and contamination is the #1 reason electronics fail...so we have all seen it.
Mineral oil / fog juice, from a fog machine, will destroy electronics equipment. It corrodes the circuit board and components.
Move all the equipment as far away from the fog machine as possible. Don't let the fog get on or in the electronics equipment at any time.
I have seen plenty of equipment destroyed beyond repair, by fog juice. You might as well store your electronics in a rain forest....

[Mark Black]

In the old days fog machines used mineral oil, but since the 1980's (thanks to Rosco Labs) they mostly use a mix of Propylene Glycol, Glycerin, and water at roughly 40/40/20 %. The good news is it's water-soluble, the bad news is it's conductive and hangs on to dust/dirt making it even more conductive. One exception is what are known as "Hazers" which may (or may not) use an oil-based mix depending on brand/model.

I have worked on some power amps from nightclubs that were so acutely gooped up inside that I sprayed the innards with Glass Plus and then literally hosed them out with a garden hose in the driveway followed of course by much blowing with compressed air and lengthy sit-time in a warm dry place. Lather/Rinse/Repeat (hmmm.... now what commercial was that from...)?

[Enzo]

Looks like common bar spooge to me.

You don;t need foggers and smoke machines to goop up an amp, though they will of course. Here in Michigan we outlawed smoking in clubs and other public places some years ago, but in lots of other places it is still allowed. And all that tobacco tar from smokers is in the air and settles on every surface. That and stale spilled beer make up that bar-stink. The cooling fan in the amp blows the tar laden air and the dust in it all through your amp making just such a mess.