The problem: I have (had) a motherboard on my file server with a fanless heatsink over what I believe is the northbridge. According to the sensor program (ksensors) I had running in Fedora, the motherboard temperature was holding around 190F. My laptop doesn't get that hot! I wanted to add some more cooling to that chipset without having to modify anything on the motherboard.
As you can see from the picture, the heatsink is in a very inconvenient location - right up against the CPU heatsink. This gave me something I had to work around, which I think I did.
Step 1: Tools and Materials
- Wire stripper
- Tiny screwdriver (eyeglasses type)
- Motherboard to be modded
- Arctic Silver 5 thermal paste (or another brand, but AS5 is the best)
- Isopropyl (rubbing) alcohol - the closer to 99% purity the better
- lintless cloth (coffee filters work well too)
- 1 foot of 22 gauge solid strand copper wire
- 40mm fan
Step 2: Heatsink Removal
The heatsink on my board was held on by two plastic tabs that poked through to the back. It was a simple matter of squeezing the snap-locks on the tabs and pushing them through (carefully!). Plyers work best.
In my case there was a double-sided sticky pad keeping my heatsink on the chipset. This was a bit of a pain to pull off but it eventually did yield. Yours might just have thermal paste. In any case, what you want to do is clean the chipset and the bottom of the heatsink completely and make sure there is no dust or lint on it.
Step 3: Add Thermal Paste
With both surfaces clean as can be, take out your tube of Arctic Silver 5. That tube is small, but it lasts a long time. You only need about as much as a half a grain of rice for smaller chips (say, less than the size of a standard postage stamp) and twice that for somthing the size of a CPU. Put a little blob in the middle of the chip.
Now you want to put the heatsink back on. Take care to seat it evenly so that the AS5 spreads across the entire chip and not just one part of it. Press those tabs back through the motherboard and make sure it's locked in place.
Step 4: Mount the Fan
Now it's time to put that fan on. I happened to have a 40mm fan from an old CPU heatsink laying around, so I used that. I had to solder it to a passthrough connector to give it power, but you might be able to skip this step. (I gave myself a nice burn with the iron doing this, so be careful if you do).
Well now, that fan is bigger than the heatsink. No problem - we'll use the copper wire to suspend the fan above the heatsink. Cut the foot of wire into two 6" lengths and strip the plastic coating off (if there is one). Now snake the wire between the fins of the heatsink, stretching from corner to corner. Push the wire down with the mini screwdriver. Then wrap the ends around the corner fins and push that down too. Leave the ends sticking up from the heatsink.
Now slide your fan on the copper wire, threading the ends through the screw holes. Then take the plyers and bend the wire down and twist it around itself to lock the fan in place. Voila - the fan is now ready for use.
Step 5: Test It Out - Conclusion
Close everything up and fire that computer up. Hopefully you should see some reduction in the chip temperature (assuming you did everything right). If the temperature is higher, you probably buggered it when you added the AS5 and put the heatsink back on.
This mod didn't actually lower the temperature of the sensor on my computer, but I'm guessing that that sensor was for a different chip entirely. Hmm. Oh well - it'll help cool a hot chip in any case.