"Douglas A. Tutty" <[EMAIL PROTECTED]> writes: > > I have a couple of new-to-me old computers. They've been well used in > what looks like a normal office environment and they're a bit grimey > inside; not just dust that blows away. I figure that I should clean > that off so the dust doesn't act like a thermal insulator but I'm unsure > what to use, since air alone isn't doing it. I don't want to remove > e.g. the CPU from its socket. (P-133, socket 7).
As another take on the issue, there's also such a thing as leaving well enough alone. Provided the computers are working now, the most likely outcome of a good, thorough cleaning, is that they will work exactly as well as before. The second most likely outcome is that one or more will stop working, and you'll need to fiddle around for hours getting them working again. >From a thermal perspective, others may have better advice, but here's my take on it. Most components don't generate much heat and can dissipate most of it through leads soldered to the motherboard, so grime on their surface doesn't matter much here. As long as the motherboard isn't entirely caked with a layer of filth and as long as loose dust has been blown or dusted away so air can flow over the motherboard surface, it'll probably be fine. The components to worry about are any that have either a fan or a passive heatsink: these components are generating the most heat, and dust and grime are most likely to affect the operation of active or passive cooling systems. Note that the issue is less a coating of grime acting as a thermal insulator and more one of dust (dry or greasy) clogging the cooling fins so that air cannot flow through them. If the CPU, main chipset chips, and graphics chips have heatsinks and fans that are relatively free of dust and the metal components of the heatsink aren't entirely coated with grime, they'll probably cool just fine. (This assumes that the case fans and grills are clean, too.) Taking a dry toothbrush to the problem and tackling the biggest clumps without worrying too much about getting everything sparkling will probably be the safest and most useful approach. On the other hand, this is hardly valuable equipment, is it? If you want a cool war story to impress friend and relatives, then I believe Marty's suggestion is sound: I recall people on "sci.electronics.repair" claiming to have had good success putting circuit boards (stripped of socketed components) in the dishwasher. I'm not sure whether the dishwasher's heated dry cycle would be recommended, and I hadn't previously heard about the leakage problems with electrolytic capacitors that Russell mentioned. -- Kevin Buhr <[EMAIL PROTECTED]> -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
