Powers off after new fan...Overheating? Need thermal grease?

[TKuser]

I just replaced the left hinge, and long fan assembly, in my T41. (This involved removing: Hard drive, keyboard, modem, palm rest w/touchpad, fan, mini PCI wireless, keyboard bezel, LCD, LCD front bezel, inverter card, wireless antenna/LCD cable connection/hinge.)

I booted back to Windows XP (which had been hibernated previously), and it kept loading the entire hibernate file, then spontaneously powering off. I tried again after deleting hibernate file, and Windows started up, ran for a few minutes, then powered off. I tried again and it happened again. Before it powered off, I ran TPFanControl and observed that the fan seemed to be spinning as normal, and the temperatures all seemed low and fine.

Fan sounds like it's working as normal. I booted into PC Doctor for DOS and ran Quick Diagnostic tests. These took about 15 minutes, and all ran fine and passed. I then went through all the interactive tests and they ran fine. Booted back to Windows, and again I experienced spontaneous power off only a couple of minutes after starting. (Actually, one time, it was running OK, and then I hibernated, and the machine powered off right in the middle of hibernating.)

The replacement fan I installed was in used condition, and didn't have any thermal grease on it to speak of. Perhaps heat isn't dissipating properly? I would think I'd see some abnormal temperatures with TPFanControl, but maybe it overheats too quickly before I can get a reading.

Some times, the machine was connected to my Mini Dock. Other times was outside of dock, connected to AC power adapter. It hasn't happened yet running from just battery, but I haven't yet tried reconfiguring power saving so that the machine is running full power on battery. No entries in Windows event logs.

Computer was on stable surface. Temperature in room is fairly cool (~70 degrees F).

Loose connector? I was really meticulous about this repair, and I thought I reseated all connectors firmly (keyboard, touchpad, video, modems/antennas, fan power, inverter). What would lead to this symptom? (Total spontaneous power shutdown, at random moments.) What could I have damaged while computer was open?

Or maybe the new fan assembly isn't dissipating heat well, and in just a few short minutes of being powered on, there is an overheated component that shuts the computer down. Do I need to invest in thermal grease? Could I get that in a store in NYC (as opposed to having to wait for mail shipment)? Are there different kinds? Is it only sold in large quantities?

I did more tests, using TPFanControl to monitor temperature (and fan speed), and SpeedSwitchXP (to monitor CPU speed). With "dynamic switching" power profile, CPU is as low as 49 degrees, and GPU stays at 45. At "max performance," CPU stays around 54 (and fan runs faster to keep it at that level). If I manually crank up the fan speed, I can get the temperature to drop a couple of degrees. So, the fan is having at least some effect.

If I perform a CPU intensive task (MP3 encoding), the CPU temperature climbs to 62, 71, 90, 93. Fan runs very fast. Then CPU drops back down to 62 right away. Suspicious, I looked at SpeedSwitchXP, and saw that the CPU (normally 1698MHz at full speed) was throttled down to 984MHz. So, it seems that the only reason the temperature got back to a reasonable range is because of Thermal Throttling stepping the CPU down.

I did this for a while, and then saw the CPU back up to 1698MHz, fan started spinning fast, and before I could get another temperature reading, the computer shut down.

For what it's worth, I can immediately power the computer back on. (I believe that with one kind of temperature shut down, you need to temporarily disconnect AC and battery before computer will allow you to power it back on, but with the other kind, this isn't necessary. I'm seeing no need to remove power supply in order to be allowed to power back on.)

So, it's seeming like the new fan assembly isn't effectively cooling the CPU. I suspect the lack of thermal grease could be the culprit (the old fan, which had been there for 3.5 years, had a rectangular area of bubbly-looking white stuff above the CPU, right where the HMM says I'm supposed to apply thermal grease, in the area marked "a" in 1130 Fan assembly), although this is new to me so I don't really understand how it all works. Could the fan itself be ineffective, though looking and sounding like it's spinning adequately?

Would a lack of thermal grease really make cooling this rapidly ineffective, or am I barking up the wrong tree? I found one article on this forum where the person reported a 22 degree drop after applying fresh Arctic Silver grease...so maybe I'm on the right track!

This page about applying thermal grease seems informative:
http://www.hardwaresecrets.com/article/274/4

While I'm at it, should I be greasing the pad that sits above the ATI graphics chip? (This pad did seem a bit greasy on the old fan, but the replacement fan's pad is dry.)

(The previous replacement fan I ordered, from "Notebookparts.com," arrived DOA - fan would not spin at all. My original fan was making terrible moaning noises, prompting me to replace. No shutdown/overheat problem happened with the original fan.)

Ideas and advice would be welcomed!

[yak]

Some kind of grease or other thermal conductor is definitely needed. These things weren't designed to work without one. Get an Arctic Silver 5 or similar paste and put it between the CPU and the cooler. I wouldn't even power it on anymore until this is done.

[seaweedsl]

Yep. Thermal grease/paste is essential for the fan to do it's job.

[TKuser]

I used Arctic Silver 5 above the CPU. I know I used a bit too much - more than the rice-size amount I later realized was appropriate - so maybe it's not cooling as well as it could. But even under continuous heavy CPU load, it didn't climb above 76 degrees CPU (61 degrees GPU). That's still pretty hot, but maybe it'll get better as it "burns in" - and it's a lot better than 93 degrees.

[seaweedsl]

76C under continuous full load sounds good. Mine does about the same and idles at 42C when not under load.

Steve

[TKuser]

I ran it under longer load and it got up to 84 (CPU), on a cool night. Should I be nervous that this isn't cooling well enough?

[seaweedsl]

Sound still ok to me still, over 90 is what I understand to be hot for full load.

But my experience is limited. Others will know more.

A great trick for lowering your CPU temp is to run Notebook hardware control and undervolt your CPU at top and bottom speeds. Top speed undervolt will save temp and power. Bottom speed (600Mhz) undervolting is more for saving battery.

Do a search on undervolting to learn more.

Steve

[ssd_thinkpad]

I noticed the brand new ibm fan replacement had already some thermal grease on it: You see these gray points of grease. Maybe your replacement had it, too?

Just a note: Another great program for undervolting is rmclock.