OddThinking

If my machine runs slowly, the CPU isn’t normally the bottleneck. I haven’t been doing much computationally intensive stuff recently. The last time I upgraded my CPU, it pretty much only meant that my infinite loops have run faster, and the perceived speed of my hard-drive has been slower.

However, over the past month, every time I have done anything computationally interesting, my PC speaker has beeped a persistent warning. Apparently “temperature sensor #3” has been getting up around 75°C. When I have brought the CPU usage back down, it has cooled off, and the beeping has stopped.

I ignored it for a while. However, this week, a rogue copy of Firefox decided that it needed upgrading so badly, that it consumed 80% CPU and caused my machine to start beeping during the middle of the night, waking me. Last weekend I decided it was time for action.

I rev up the machine, and poked my fingers in its innards. System fan is spinning happily. CPU fan is working fine. Doesn’t seem too hot. Ooh! The video-card’s heatsink is very hot – and, oh my, the video-card’s fan doesn’t seem to be turning.

I shut-down the machine, and replaced the video card with an old spare. The old fan does seem to have seized up – it’s hard to turn by hand. I’ve fixed it!

I re-start the machine and launch a game. Drats! Soon the machine is back to its beeping (and the game is running very slow on the old video-card!) I play for a few more minutes until I can handle the beeping no more, and start to quit. The motherboard can’t wait, and simply cuts the power – the screen goes black.

Okay, so it wasn’t the video-card. Maybe the problem is the CPU is getting hot, but isn’t conveying its heat to the heatsink. The thermal paste may not be making good contact.

The CPU fan is clipped into the heatsink and to the motherboard. I remove the clips to the motherboard, and remove the heatsink and fan. As I lift away the heatsink, I find – to my horror – that the CPU is cemented onto the heatsink with dried-up thermal paste. I have just plucked the CPU straight out of the ZIF socket without releasing it first. I’ve bent pins and generally treated it pretty badly. Looks like I’ve just destroyed a CPU – and possibly another motherboard too.

Not really wanting to buy a new fridge, and with nothing to lose, I continue the abuse. I separate the CPU from the heatsink with a screwdriver for leverage. I bend the pins back straight with my fat fingers and with no ESD precautions. I insert it back into its socket – somewhat gently. I don’t have any new thermal paste, so I just rest the heatsink on top of the CPU, separated by a couple of crusty layers of dried thermal paste. I clean up some of the dust that has embedded itself in the heatsink and plonk on the the CPU fan and clip it in place.

Now, I watch with interest to see what happens when I try to boot up this damaged PC.

To a shout of joy, it still works!

In fact, it’s better! It is now cruises around 35-45°C, even in a warm room on a hot day, running games.