I've just had an eye opening experience with the destructive power of dust in electrical connections.
I have an Arcam Alpha II hi-fi amp I bought back in 1984, which I replaced about 11 years ago due to ever worsening R and L channel drop out combined with intermittent crackling which was becoming less intermittent and serious as time went on. It got really bad.
It was sadly replaced (sadly because it was an award winning amp) and confined to the depths of a cupboard.
And there it stayed until very recently when the replacement amp developed a serious sound balance problem (no crackling). Have no intention of sending good money after bad having it repaired as these days free estimates don't exist with audio engineers. It was gonna cost about £50 just to have it looked at.
Been there and done that with a CD player the year before last and all I got for my trouble was being £50 out of pocket.
So (temporarily I thought), out came the Arcam as I remember being able to get it to work by jiggling the selector switches and tape loop switch (that's tape recording for the benefit of the children here). And just as when I packed it away 11 years ago I could get clear sound for at least 5 minutes before the jiggling act was further required.
Not perfect, but would do until I could get a new amp.
Anyways, while looking on line at new amps, I decided to have a google for the causes of crackling and channel drop out, and a great many different suggestions were being put forward on various forums. Replace this, replace that etc, but the most basic possible cause was dust!
No way could dust cause such serious crackling and complete loss of sound in either/both L and R stereo channels. Could it?
As it was a very cheap outlay for a possible fix I thought what the hell, give it a go. Bought myself a can of compressed air and a can of what is without doubt the best electrical switch cleaner/lubricant out there, Servisol Super 10, and proceeded to blast out and then lubricate every pot (potentiometer) and switch I could find as well as cleaning the dust from the entire board/ power supply etc..
Connected it back into my system and miracle of miracles, that 34 year old amplifier sounded like new. And now after being used constantly for a few weeks, there is still not a crackle from anywhere and left and right channels are rock steady and equally balanced.
Selector switches, volume, balance and tone controls are also completely silent. Crackle free.
I was gobsmacked. I didn't have the internet when I consigned this thing to the cupboard and would never have thought it was anything other than a costly part or parts replacement.
So for an outlay of £13 total I've saved myself the cost of a new amp. I thought the sound may be different after all these years, maybe slightly harder, an edge to it maybe. Not so, still a lovely punchy but smooth sound, probably better than the replacement I bought.
The moral of this story is obvious. Don't underestimate the damage dust can do to switches and pots in electrical equipment. The shorting out it can cause can be surprisingly severe. Try cleaning and lubricating before anything else. You may get a surprise as I most surely did.
And thus ends today's lesson.