Hi,

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. I know of techs using compressed air, but that seems terribly messy to me.

However, some example are so badly fouled the only way I have found to clean them properly is to submerge the PCB and heatsink assemblies in hot water and detergent and scrub them just like dinner plates and saucepans. In order to thoroughly dry the PCBs, I have used an oven set to low temp, hot air from a room heater or gun and simply the sun on a warm day.

This is obviously a very time consuming process requiring a lot of disassembly and reassembly, cleaning the fans themselves is one of the most tedious parts.

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

Turns out they had been in the same rack with another amplifier that went up in smoke, filling them with carbonised fibreglass soot. This took more than the usual amount of time and care since a 2kW SMPS is built on the same PCB.

Anyone know an easier way or have useful comments?



..... Phil