T41p Problems - Overheating?

[MatthiasMeyer]

Hello all. I'm a first time poster here, so go easy on me!

I've had a T41p for about 3 or 4 years now and I've been very happy with it. However, recently, I've been having a particular problem:

Beginning maybe a year ago, the machine would, at times, spontaneously shut down when playing games. It didn't seem to happen at any other time, and it happened only very infrequently, and when the laptop was plugged into the wall.

Recently, it began to happen even when the machine was not plugged into AC power. Furthermore, it will also happen when the battery is out, and the machine is running directly from the wall.

I used to think that this was an issue of overheating when both the battery charger and the GPU were active, but now I've been thinking it's simply the CPU/GPU overheating.

The fan appears to be running just fine, and the problem happens when the unit is sitting still on the table (not just when it's moving).

Yesterday I removed the keyboard and looked under the heatsink. There was normal thermal compound between the CPU and the heatsink, but between the heatsink and GPU, there appears to be some kind of white pad. It seems as though there used to be some type of black goop, as well, but only slight evidence of its presence remains visible.

I sent this unit in for service once (USB ports were out) and I assume they replaced the motherboard... could it be that they didn't properly reapply some kind of thermal compound between the heatsink and GPU?

I guess the root of my question is this:
1) Do you think I've made a reasonable diagnosis of the problem, and, if so...
2) What do I do to ensure thermal conduction between the GPU and heatsink? Can I remove the white pad entirely and replace it with liquid thermal compound? It seems fairly thick so I was hesitant to do this. Should I buy some special thermal compound for this connection?

Any advice would be appreciated. I'd love to keep my beloved Thinkpad running a few more years!

EDIT >> Also, what is the best way to read back the temperature of the CPU and GPU?

[aaa]

tpfancontrol can read all the available sensors.

[richk]

There is not and should not be thermal compound between the GPU and the thermal pad. (some are black and later ones are pink) I would suggest applying new thermal paste to the CPU, after removing the old stuff with denatured alcohol. (I use arctic silver - be sure to use thermal compound and not thermal adhesive. You need dynamite to get the adhesive off.) Someone else can give you a better answer than I can about temperature monitoring software. I never found any I liked very much.

[Tim M]

tpfancontrol can read all the available sensors.

As can NHC. I tend to prefer NHC as I can use it to control fan speed and CPU voltage.