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Guido's cooling system for the T43p

The T43p has a real problem with the fan noise and cooling in general. The fan needs to be always on as the cooling system is not very sophisticated.

Here is a description of the cooling system improvements which I made using some small cooper sheets (0.7mm thick). The result is that the temperature of the Southbride has gone down by 5'C!

In summer I will however need a fan control script as the Southbride will probably not go below 38'C during normal operation (the embedded controller switches the fan off at 37'C and on at 43'C).

The GPU which is next to the Southbride and can get hotter than 45'C. Therefore don't connect Southbride and GPU.

This article is about improving the really poor thermal design of the t43p. For a description of how to fix the fan noise problem see Thinkpad fan-noise fix.

The keyboard from the bottom. The little board is for the red mouse pointer device.

I understand now why IBM did not cool the northbridge. It looks like there is a lot of space above the silicon but this space is needed for the little board of the mouse pointer under the keyboard. There is only 3mm of space. Very little for a cooling system. The only thing one can do is spread the heat over a larger area.

The southbridge which gets too hot even with low cpu speed and power saving of the GPU is under the mini pci WiFi card.

The idea is to cool the southbridge with a cooper sheet and hold it in place with the keyboard screws. I made first a cardboard model and then cut the piece out of a 0.7mm cooper sheet.

Paint it black and put heat resistant insulation foil under the cooper.

A small piece of soft rubber between the WiFi card and the cooper presses the cooper against the southbridge.

The pcmcia slot has on the side some holes. This causes to fan to suck air directly via the pcmcia slot. I covered the side with a bit of plastic to improve the air flow through the computer.

Now the northbridge.

I used some thin plastic foil which can be used for insulating transistors on an aluminium cooler. This plastic can withstand 200'C. From this plastic foil I made a half open box to hold the cooper in place and insulate it against the resistors which are mounted on the northbridge chip.

Attach the cooper to the plastic foil with a little bit of glue.

The "heatspread" over the northbridge.

A soft rubber between the keyboard and the cooper presses the cooper against the northbride.


© Guido Socher, guidosocher at gmail.com, ->back to the main t43p article