Thinkpads Forum

I scored an X61 with a T8300 (2.4GHz Penryn!) for $50 on eBay best offer, so I'm pretty excited to receive that. However, I'm remembering the reason I got rid of my T8100 X61 in the first place: the [censored] thing is too hot!

In the past people have thought the Wi-Fi card was to blame, either because it's a bit old (4965 or 3965 intel) or because of poor power management in Linux, but this isn't the case. I've previously replaced it or removed it altogether and had the exact same warm palmrest on the right. I think it is some part of the chipset on the underside of the motherboard.

Has anyone tackled the issue more in-depth?

If the right palmrest feels hot, then the mini-PCIe card(s) underneath are causing it.
There are two mini-PCIe slots under the right palmrest, and they're usually populated by the wifi card and the Turbo Memory card (or a WWAN/3G card).

Turbo Memory is junk, so remove it.

Most recommend replacing the stock wifi card with either the Intel 6200/6300 or the Atheros 9385, but some use a Cardbus wifi card.

The ICH8M southbridge is to the right of the RAM slots, but it's on the underside of the system board. If you believe that this is the cause of the hot right palmrest, you can probably find a thermal pad big enough and thick enough to get it to contact the bottom of the chassis--that is, if the chassis is made of magnesium alloy. I don't know what material it's made of.

axur-delmeria wrote:that is, if the chassis is made of magnesium alloy. I don't know what material it's made of.

AZ91D magnesium alloy.

xiphmont wrote:AZ91D magnesium alloy.

A quick google search yields conflicting values of thermal conductivity. One says 41.8 W/mK, while another says 72.7 W/mK.

It's a lot worse than Aluminum (>200), but better than stainless steel (15-24) and carbon steel (36-50).

I was going to post the same question but I'm almost 100% sure it's not because of the default wifi card in there. I've tested it without a wifi card in there and it was still hot running a usb file transfer. That is what I think is the problem.

I actually have a newer intel 6235 with bluetooth work in the wwan slot with nothing in the wlan slot. It is still very warm.

I think it is more related to the southbridge. I am thinking about extending the original heat-sink to reach the chip.
Here is a possible solution:

https://drive.google.com/file/d/1V59oAF ... sp=sharing

the only obsticle on its way might be the sim card slot (for some models).
the closed assembly looks like this:

https://drive.google.com/file/d/1TMUK0c ... sp=sharing

vavet wrote:I think it is more related to the southbridge. I am thinking about extending the original heat-sink to reach the chip.
Here is a possible solution:

https://drive.google.com/file/d/1V59oAF ... sp=sharing

the only obsticle on its way might be the sim card slot (for some models).
the closed assembly looks like this:

https://drive.google.com/file/d/1TMUK0c ... sp=sharing

Yes I believe you are correct, I may do some mods on it as I've inherited a few x61t sxga+ from my dad's collection. x61t is actually my favorite and daily driver even though I own probably 30 newer laptops.

Is that a flat sheet of Aluminum?
Better insulate the underside so that it doesn't short out other components.

But IMO it's easier to use the magnesium chassis as a heatsink.

axur-delmeria wrote:Is that a flat sheet of Aluminum?
Better insulate the underside so that it doesn't short out other components.

But IMO it's easier to use the magnesium chassis as a heatsink.

For now its just piece of paper . But yes The idea is to use flat sheet of aluminium, and yes it definitely need to be isolated.
I will also try with chassis. My main concern with chassis is that I might get a hot spot underneath.

But what if the heat transfer goes the other way--from northbridge to southbridge?

axur-delmeria wrote:But what if the heat transfer goes the other way--from northbridge to southbridge?

Good point! I can do a load test on bare motherboard and measure the temps. If the northbridge gets much hotter then definitely have to think of a different solution.

any progress?

returns values for the southbridge as, it seems, under 'temp3' and 'temp2' - I stuck a frozen piece of chicken to the underside of the x61s and watched 'sensor' data. temp2 and temp3 fell quickly.

I've done the following and, with the fan disabled, am getting temp2/3 readings of 37 degrees:
Disable multi-core in bios
Cap cpu to max of 1200000Hz
Set TX power of wifi card to 1mW
Disable ethernet port

Other suggestions?

code used to do this and other ideas in this bash script:
http://jesseo.com/kites/power-x61s.sh