We’ve had Stan’s computer with us for the last week. Actually, it’s Dawntreader, one of Lisa’s old work computers. Dawntreader had this habit of playing “Fur Elise”. No – it’s not a virus. It’s a built-in tune that the motherboard plays as a warning when it detects that the processor is overheating, or a rail voltage is fluctuating, or something. (If you do a Google search on “Fur Elise”, it is interesting that a reference to a “Damage Free Intelligence” PC motherboard feature is one of the links on the first page of results.)

This tune was driving Stan and Jeanne wild with its incessant noodling. For a while we suspected a voltage problem, because whenever we took the PC back to our house and cleaned it out and kept it running for a while, we never heard the music. Finally last week we took it back again and checked it out, and this time we heard the music more than 50% of the time.

We had a choice – we could try replacing the power supply, which after all was quite old, or we could try replacing the processor. More research revealed that the processor chip currently installed in Dawntreader, an AMD K6/233 in fact, comes up often in online reports from people complaining of PC overheating problems. So we decided on option 2 – we’d replace the chip with an alternative, assuming we could still find someone who sold Socket-7 processors.

The rather ancient Pentum MMX 233MHz seemed like a good candidate, as it runs at a lower core voltage than the AMD, which can’t hurt. Compuvest.com would actually sell us one online, and so we bought one from them earlier this week. Which brings us up-to-date with today, which is when the UPS man dropped off a small brown box containing the processor and associated fan unit.

So, this afternoon after work, I took the page of motherboard jumper settings that Lisa had prepared, and opened up Dawntreader on the kitchen table. I had to remove the RAM to get at the existing processor fan clasp, and when the fan popped off I could see where all the themal paste between the process and the heatsink had all oozed out. Bleh. Clearly less than optimum cooling was going on here.

I lifted the socket lever and the AMD chip slipped out easily (zero-insertion-force sockets are great), put the new Pentium chip in, and unpacked the new fan unit. Then things got stupid. After smearing some fresh themal paste  on the top of the processor, and lowering the fan unit into place, I found that the clip that was supposed to apply pressure to hold the heatsink firmly in contact with the processor was applying it off center so that the heatsink would pop up at a slight angle, contacting the processor on one edge only. Not good! Reversing the clamp seemed to work, but put the clasp in rather close proximity to the RAM slots. Luckily the RAM chips slid into place with only slight gap between them and the clasp, and the heatsink seemed securely attached to the processor.

The jumper setting changes must have been correct, because Dawntreader booted up without problems, and we haven’t heard “Fur Elise” once since then.

We’ll drop Dawntreader back to Stan on our way to the Rush concert tomorrow.