exxos's Atari, Amiga & retro forum

So when I did my recent upgrade I noticed that the underside of the Mega ST4's
RF shield had black dust on it. It was not there the last time I had it apart for
cleaning about 6 months ago.

It is on the part of the RF shield that sits directly over the P/S. The Mega seems
to be working fine and the fan is running so I'm not sure what to make of this.

I visually inspected the P/S and didn't see anything blown.

Should I be worried? :)

That'll just be atmospheric carbon dust from diesel vehicles accumulating over the top of a hot component carried there by convection. That's normal in any equipment with a cover over a hot component with natural ariflow through it.

As said above. Pollution. I see it around carpets, sockets on walls etc. And to think we breathing in all that crap as well.

stephen_usher wrote: 19 May 2021 09:47 That'll just be atmospheric carbon dust from diesel vehicles accumulating over the top of a hot component carried there by convection. That's normal in any equipment with a cover over a hot component with natural ariflow through it.

Fascinating. What's the mechanism by which it's deposited, do you know? Sudden change in convection direction?

BW

Not sure, possibly static charge.

Well, thanks guys.

I find the part about diesels interesting. I live about 4-5 miles outside of a city
with a population of around 4500-4800 or so. Can't remember the last time I
saw an actual diesel within miles of me. Do see them on the 4-lane highways
but that's literally miles away.

So does this stuff carry that far? Ugh.

Diesel exhaust loves to fertilize allergies and moss on things down wind


Tom

I understand....still, I live in the hills of Appalachia (Eastern Kentucky, to be exact).

I would say most likely not unless diesel dust loves Mega’s. Now if you have black else where then maybe but with your local I’d say very unlikely especially if the Mega is the only place it showed up. :D. The Atari supplies run so hot it could be some out gassing from components on the supply.

Fans with sleeve bearings (instead of ball races) will grind themselves to bits over time creating fine dust. So could be fan guts.