On Wednesday, October 1, 2014 5:34:03 PM UTC-7, Phil Allison wrote:

ever since someone had the brain wave of putting "computer" fans inside power amps - service techs have had to deal with dust and fluff clogged heat sinks and filthy PCBs.



When such amps are installed in a music venue for years, cigarette smoke, artificial fog oil and moisture add to the mix making the result truly appalling.



In most cases thorough vacuuming and cleaning inside and outside surfaces with a damp cloth is sufficient.

Recently I had to clean a couple of Crown XS700s that were completely fouled with black fluff that proved to be electrically conductive !!

I'd try Plasti-Tac and/or Handi-Tak. Hard to describe, these are clay-like sticky
products, you rub 'em like an eraser over the surface to be cleaned, then
knead them like bread dough and the crud mixes in and never is seen again.

For some scorched and corroded gizmos, I've also used glass-bead
blasting.

For anything large, though, the old (before water-clean flux) solution was
an alcohol/water azeotrope (mixture). Rinse, distill the dirty solvent, and use it
to rinse again. As many times as needed...