R50p Overheat

[Roger Davis]

System - R50p running Ubuntu 14.04

Symptoms - Idle temp about 45C, severe load reaches about 92, cycles there as long as load is high, drops quickly when load drops. Normal operation about 60 or so. (Temps are from memory a few days ago, but sure about the 92). I think this is probably abnormal heat?

I suspect dirty heat sink(s), and / or poor thermal paste on heat sink(s). Fan seems good, output air is pretty hot under full load.

Does this machine even have a CPU heat sink? I can't find a diagram showing one, though I think I saw one for the GPU.

If I want to check out my guesses, how do I get to the CPU and GPU to check and fix these things? Any trick to removing the heat sinks?

Any other ideas on the cause of the problem?

Thanks!

[Pokrzept]

Please check R50ps HMM @ http://thinkpads.com/support/hmm/hmm_pdf/39t6190.pdf, page 89. It's quite easy to remove it, all you have to remove is HDD cover, palmrest and keyboard. Please do mind that such old laptop may show its age under heavy load - I can bet that your CPU runs @ 100% most of the time even if you think that you do not stress it too much. Modern software is ment to run on multithreading architectures and your Pentium M can handle only 1 thread at the time. Whats more Ubuntus GUI is a really bad example of code optimization - well most of apps are developed really bad these days but that is material for another topic.

[Roger Davis]

Thanks for the reference. Now it makes sense... the CPU heat sink is integral with the fan. Is it sometimes or often really stuck down?

And I presume I can also see the GPU heat sink at that point, and can re-grease it then?

Again from memory, CPU runs normally at just a few percent at idle, mostly at about 30 ~ 40 %, and of course near 100% when it gets really hot.

Thanks!

[ajkula66]

And I presume I can also see the GPU heat sink at that point, and can re-grease it then?

No re-greasing there. The GPU on R50p is covered by a small square heatsink that leads nowhere. One of the absolutely dumbest solutions that IBM ever came up with.

You could install a M10 long fan which would cover both the CPU and GPU. FRU is 13R2657. While you're at it, swap your Banias CPU with a Dothan one that could be bought for $5 or so, they run cooler. You'd be looking for Pentium M 735/745/755.

[Roger Davis]

Excellent info, but leads to a few more questions -

- I found SL7EM- Intel Pentium M 755 2 GHz 2 MB 400 MHz Socket 478/N,479 for about $20 on Ebay, refurbished(?). Is this one ok? It runs a bit faster, but still cooler? Do you know of a better source?
- I guess the M10 long fan would work with either the original processor, or the one above?

Just to be really clear, here's full info on the computer, some repeated
IBM ThinkPad, R50p
Type 1832-22U
S/N 99-B7127 04/04
CPU type PM, speed 1.7
Optical Drive
OS - Ubuntu 14.04

[ajkula66]

Excellent info, but leads to a few more questions -

- I found SL7EM- Intel Pentium M 755 2 GHz 2 MB 400 MHz Socket 478/N,479 for about $20 on Ebay, refurbished(?). Is this one ok? It runs a bit faster, but still cooler? Do you know of a better source?

I really don't know how one would refurbish a CPU. Try posting a WTB (want to buy) ad in this forum's Marketplace, you might do better.

- I guess the M10 long fan would work with either the original processor, or the one above?

Yes.

The beauty - as well as the danger - of these machines is that one can go nuts with various upgrades...

Happy upgrading.

[axur-delmeria]

Refurbished might simply mean "extracted from previously working laptop" in this case