Charles Basenga Kiyanda

Living in the desert: A lesson for the computer user

I’m writing this post using my brand new Aopen motherboard. (Nothing to brag about, it’s a quick thing I found on ebay that would support my athlon 64 single core socket 939. If you have no idea what I’m talking about, just know that a very important part of my computer died unexpectedly and I had to replace it.)

I was stunned when the motherboard died. To be honest, there were some signs before the whole thing died. It really started with keyboard problem. Keys would get stuck. Not physically stuck, just virtually stuck. The keyboard wouldn’t stop typing a particular key, even though the key itself would depress. Bizarre. Then I couldn’t access the bootloader using the usb keyboard, but it would still boot. I could access the bootloader when the keyboard was plugged in ps2. Then it wouldn’t boot when plugged in ps2, but would boot in usb, still no bootloader access. Then it wouldn’t boot at all. (Again, if you don’t understand a word I’m saying, just think weird problems that seem keyboard related, but not really. In the end, the computer didn’t work at all.)

I’m trying to make a short story here, so let’s just say that I fiddled with everything, cleaned all the guts of the computer, took everything out, put it back in, still no can do. So after going through swapping all the parts I could and trying to narrow in on the problem, I figured the problem was the motherboard. So, onto ebay, find a motherboard, order, ship, wait…wait…wait…wait… install new motherboard, it works.

Except I still have keyboard problems.When a keyboard is plugged into usb, I can boot, but I usually can’t access the bios nor the bootloader. When plugged into ps2, I usually get a “keyboard error or no keyboard” error or a “keyboard locked, unlock the key” error.

It’s bizarre to say the least. I also spoke to a friend (who also lives in the desert in Los Alamos) and he has very, very, VERY similar problems. We were both speculating that static electricity was the problem, but couldn’t really say why, especially since these were keyboard problems. I think I have an explanation.

It is indeed static electricity (at least, in my theory). Keyboards are basically two large thin sheets of plastic one of top of each other separated by a little space. (There’s actually third sheet of plastic in the middle witha bunch of holes in it.) The top and bottom sheets have a bunch of electrical circuits on top and on the bottom, so that when you press a key, the top and bottom sheets meet across the non conductive middle one, contacts meet, current passes, etc, etc. The point is that you have these really large sheets of plastic suspended in mid-air, almost. It only touches plastic pieces, but most importantly, plastic of a different kind.

Now here in the desert (well the high desert in New Mexico), the air is really dry, especially at this time of year. Right now, we can get to 5 to 15% of relative humidity during the day. That’s really dry. With dry air, you can get charge buildup on the different materials. For example, people here get really annoyed because they keep getting shocked when touching the car door. Literally dozens of times a day. (It really annoys me at least.) Plastics can build up charge quite easil. So there you have those really big sheets of dry air in conditions favorable to building a static electricity charge. So you end up with these three sheets of plastic which, by design, can’t touch each other, in really dry air. So they get charged.

NOW!!! Dust gets attracted to statically charged objects. (That’s actually a good trick to dust off things around the house.) So these three sheets of plastic end up covered in dust. Dust can be conductive. And so you end up with essentially random short circuits in your keyboard.

Now the problem remains to explain why there’s a different behaviour between the ps2 operation and the usb operation. There’s also the question as to why the problems would occur more often at boot time.

I have personally no idea and I welcome idea. Some of my suppositions is that the usb connection is low-powered when compared to the ps2 operation and also there could be a sutained high current at boot level in either or both of those connections. This current might disappear after the OS loads. I don’t know. I’m just throwing ideas out there.

In any case, all this to say that when you have a computer in the desert, you should keep your keyboard clean. Now if only I could find an appartment in the US without carpet everywhere, that might help.

[Update 1 (May 23 2008) : New motherboard and still have intermittent problems at boot. Bought a cheap wireless keyboard and mouse to test my theory. No luck. Well, that was a nice theory while it lasted. In any case, dust in keyboard does not break things even in the desert.]

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