NEW INFO: Pink rubber pad on heatsink & T43 fan issues

[JHaislet]

I removed the heatsink on my T43 and was looking at the thermal interface material which covered the video card. More about that in a second. My heatsink actually had a greyish heatsink paste on the CPU (no thermal pad) and it looked a bit like some sort of artic silver, except it was too dry & cracked, maybe some generic brand.

Anyways, on to the graphics card. The part of the heatsink which covers the graphics card was strange. There was this brown substance that looked like hard, dark, carmel candy. This was adheard directly to the heatsink. Then there was this pink rubber pad, which reminded me of the top of a bandaid in it's texture. It had these tiny dimples that made contact with the ATI heatspreader. What I found odd about this rubber sheet was it's ease as to which it came off. It peeled right off, like it was just a protection sheet for the brown thermal material. The pink sheet didn't melt one bit from 2wks of fairly heavy useage in my thinkpad.

So I peeled off the pink rubber sheet and applied some AS III to the ATI heat spreader (to keep the brown TIM from adhearing to the heat spreader) and everything is now working fine. While the fan speed and noise didn't change any my normal operating temperature did seem to drop 1-3c. For example, while surfing the net with the CPU set to "Adaptive" and PowerPlay Enabled (even while on AC), the CPU stays at 800mhz and the X300 stays at 105mhz, and the system stays between 43-44c. It might go up to 45-46c if I'm downloading some massive files or doing something disk intensive (burning a DVD), but for the most part, it stays around 43-44 on AC with the room temp at about 76 F (I have a temp probe on a digital multimeter).

What's interesting though, is the air temperature coming out of the exhaust vent. By positioning my temperature probe right inside the middle vent and with the probe touching the heatsink fin (on its end), it displayed a reading of only 94 F (34c).

Yet I positioned the probe directly under the laptop, right under the blue scroll key above the touchpad, and its reading about 105F (42c). The part that apears to be the warmest is actually a bit to the right of where the touchpad is (mPCI location). This is with wireless ON and the DVD drive in the bay. The HDD stays right at 32c most of the time.

[Zeitgeist]

While the fan speed and noise didn't change any my normal operating temperature did seem to drop 1-3c.

Thanks for the nice report. But when the fan noise did not change why did you risk your warranty?

[JHaislet]

I honestly don't think I did. This pink sheet appears to be something that SHOULD have been removed when the heatsink was installed. I can't for the life of me imagine that this should have been left between the heatspreader & the heatsink. I guess worst case, I'll just pick up a new heatsink & fan assembly if it ever becomes an issue.

Also, the dimples on this pink sheet are spaced in such a manner that they actually REDUCE the surface contact by at least 50% between the heatsink & ATI spreader. I thought the whole point of using thermal interface material or Artic Silver was to fill in these gaps to facilitate better transfer.

I do believe my heatsink now removes more heat off the X300, but I'm fairly confident its the Intel 2915 wireless card, or a mis-programed sensor that's causing the fan to kick up another notch.

[FTC]

Hi,

Some days ago I also removed the pink sheet from my T42's heat spreader... I was so convinced that it was only a leftover that should have been removed during manufacturing... But later on I read the hardware maintenance manual for the T42 more in detail and there it states clearly that you are *not* supposed to remove it in the M10 heatsperader, which is the one I have. I assume it is just to facilitate further maintenance without the real TIM bonding to the GPU... however I am absolutely sure it can only help with thermal dissipation to remove it... since you are improving effectively the thermal contact between GPU and HS.

[JHaislet]

That was my thinking as well. Mine was the M24 heatsink/fan assembly, but the same principles still apply. I also put down a thin layer of AS III on top the ATI Heat spreader. I figured by doing that, if the thermal material did melt some, it wouldn't stick to it.

From my continued observations this evening, I have noticed that the bottom of my laptop, where the video card is, does not feel as hot as it did before removing the pink sheet. This granted, my subjective opinion, even though the CHC temperature readings don't show that much of a reduction.