..but here's what happens when you own a Dell but not a vacuum cleaner:

According to Pete MacDonald, that's the front access to a USB panel, not that you'd know it.
This too was once a computer, Stateside reader Ian Keyes believes:

Fellow American J C Edmond, who owns a computer repair shop, provides evidence of why one of his customers' kit kept overheating:

COMMENTS
oh GOD, the smell!!!
This is all very interesting, and I've seen many at least equal, but it doesn't really convey the awfulness of opening a computer that has sat inches away from a heavy smoker for many years, the nauseating, nostril clogging stench. It also doesn't convey the disgust at the texture, its not just dust, its sticky, cloying, revolting. After having one of those in the workshop the stench lingers for days. What you need is smellovision and feelovision.
Re: Smoking and PCs
Many years ago when I was starting my PC support habit I had to fix an old PS/2 (the IBM type, not the Sony one) that had been on the desk of a heavy smoker. I took one look inside and refused to touch it - several inches of brownish tacky sludge covering everything inside the case. Even back in the early 90's it was agreed by all that this was a health hazard..
He ended up having a new PS/2. And smoking at the desks got banned shortly afterwards with the company setting up a cancer cabin for the addicts to go and smoke in.
@AC 21:18, Re: Except
""Don't use a standard air compressor ... They typically don't have filters on them" - the one in the paint shop will."
Except the dude/tte running the paint-booth won't allow anyone with a dusty old computer anywhere near the place.
""don't crank the PSI" - not a problem as long as you keep the blowgun at a sensible distance."
Are you aware of the phrase "human nature"? Far fewer problems my way ...
TVs too
colour CRT TVs this is; the ones that came from a smoking household and had been on 12 hours a day for a few years tended to grow sticky tendrils about the back of the tube and over the HT portions of the PCBs. A vacuum cleaner and brush would only ever be partially successful at removing it before you had to start working on it. Trike was the best stuff for getting it off.
