T61 weird readings and crashes after upgrading to used T8100

[eyeland]

I just upgraded my T61 -7661 from T7300 -> a 2. hand T8100
I flashed middletons bios long ago for some SATA 2 testing, so I have have no idea if the thrmal error would have popped up on boot.
From what I have gathered in other threads, the MB I have is indeed of the kind that would trigger the error.
While changing the cpu I also replaced the fan as it was beginning to make a grinding noise. (I didn't change the entire heatsink, only the fan, which prooved to be the most difficult part of the entire operation.) I live in a rather remote location and I got tired of waiting for the Arctic Silver Ceramic that I ordered, so I ended up using the "stars DRG-33" white thermal paste that shipped with the fan.
I am experiencing some odd readings and I am trying to make heads and tales of it which is a tad difficult due to all the factors at play here.
When I boot the machine, the temperature readings in TPFC (as well as the cpu load reading in the win7 gadget) are very odd as they sometimes jump abruptly and it seems that the cpu temp reading falls out altogether once in a while. Now, after being on for 20min, it seems more stabile indeed. I have been running passive for 15min on default "balanced" powerplan, adaptor not plugged in. This has resulted in a stead temp climb from 47C to the current 58(fell to 57 while typing this)
Hwmonitor: THM0=58, THM1=48, Core0=42, core1=43.
All in all, both temp and cpuload seems to be higher than I had expected (running crome, skype, MSE, TPFC, HWmonitor)
Granted, the thermal paste probably suxx and last time I dabled in apliying it was almost 10years ago, still, I think I did a pretty good job getting the drop of grease spread thin and evenly. Moreover, any problems as to installation of fan or paste should not result in these odd readings.
Just now, the tpfc reading jumped from 60 to 75
UPDATE:
Tried reinstalling TPFC and upon restart it reported 96C (gadget reporting 100%cpuload) while the laptop was cool to the touch underneath and the exhaust air from fan only slightly warmer than my hand. Tried another reboot and changed a adaptive power and speedstep in bios to maximum performance. After this, the tp would turn off just before reaching loginscreen and it would no longer detect the AC being plugged in. Took battery out and back in, tp detects AC again, booting resulting in same behaviour, sudden turnoff before login and loss of AC detection. Changed Bios back to balanced, still the same result. Only got in to windows by booting without AC attached.. this is getting stranger and stranger...
As I entered windows,(gadget reporting 100%load) TPFC reported 85C, then 96, then 85, then 75 declining to 60..
Have I screwed something up? is the 2.hand cpu defective? any ideas at all?
Don't know if some of the events could be random and unlinked.. experienced a similar problem with loss of AC detection a year ago, but the machine has been running smoothly since... I am at a loss
Running stable for a while now. Bios on balanced, Powerplan on balanced fan back to the behaviour of the days before TPFC(((
Still getting odd readings but the laptop seems VERY cool to the touch as well as the exhaust.
Makes my lap feel cold, never had that before.. still.. I want to regain control over my sensorreadings and my fan before I start rendering stuff and playing around with rmclock and such..
problem appears to be worse than I thought
Update2:
Just after editing my last post, I ran utorrent, crome, closed and opened skype and bam, tp died, loosing AC detection. removed and replaced AC and bat. Reboot, same thing happened again, and again etc.. as I could not get to login, I let windows run startup repair while doing dishes.. after 30min it finished, froze and rebooted itself, same thing, crash and no AC.
Fiddle with bat and Ac again, this time attempting to boot to Ubuntu, same thing, crash, no AC. At no point has the tp gotten more than lukewarm and it has certainly been very cold compared to my experiences with the old T7300. Rebooted again and again to no avail untill it suddenly accepted booting to Ubuntu from where Iam writing now..
I am getting a little frustrated as the randomness of the issue makes it hard to choose apropriate actions.
The T8100 I bought from ebay was cheap (won it at 45$) but the icelandic seller seemed very nice and I felt no reason to be suspicious.
So far I have only learned one thing: Do NOT replace any vital parts in your only machine while working on your dissertation abroad
Eagerly awaiting any input, copied my posts from notebookreview as I am getting desperate

[Harryc]

My rule of thumb doing problem determination with electronics is very simple. Undo the last thing that was done before the problem occurred, then move on from there...CPU upgrade eh?

[richk]

I have always believed that using a Penryn on a board that wasn't designed for it is a bad idea. I think all the modified BIOS (or hitting ESC at startup) does is to bypass the error. You still cannot read the digital sensors correctly. The risk is that you can overheat and cook the CPU or other parts and not trigger a shutdown or slowdown. Also fan speed may be set incorrectly. Others would disagree.

[eyeland]

CPU upgrade eh

Cpu upgrade yes, but also fan replacement (compatible fan), and stock Thermal paste.
Furthermore, the modded bios that was installed long ago is of interest..
Had it been anything "easier" than a cpu installation I'd have switched back to the T7300 right away, but I'd love to hear any thoughts on the issue before going there.
If I put the T7300 back in and it works, the only thing I'd know for sure would be that the T8100 causes the problem whether due to being faulty or not..(it COULD still be another issue in conjunction with the T8100) and I'd then need to reinstall the T8100 again to progress further if not asking the seller for a refund right away...

Further observations so far:
No crash has ocurred while idling

Gonna keep the TPFC speed on manual, value 7 and see if I still crash with maximum cooling.

[eyeland]

using a Penryn on a board that wasn't designed for it is a bad idea

Of course I agree that there is a risk on going ahead with an upgrade like that.
That said, the number of users who have had success with this seems to be substantial and thus, after following the threads on the topic for a while I took the (some would say very stupid) chance and went ahead with it.
I totally respect your opinion, but I went ahead with this knowing the risks.
I didn't start this post to complain about it or in search for "I told ya so" merely in the hope that someone would have a specific idea of what might be causing the crash.

Further observations:
Not only the CPU reading in TPFC is affected.
Once in a while, other sensors report 1C and furthermore, "new" sensors (eg. 8 & 12) which are not nomally present suddenly shows up to then dissappear magically
Been running stable in my lap for a while now, running crome, winamp, skype, TPFC(manual=7), HWmonitor and realtemp resulting in the following unstable temps:
TPFC - 1 cpu: 50-58C
Real temp 3.60: 38-48
HWmonitor: THM0/1: 43-57/43-56
Hwmonitor Core o/1: 36-40

[eyeland]

Any idea if the Lenovo factory thermal paste is conductive?
Grasping at straws here

[RealBlackStuff]

The obvious suggestion is, to get proper AS5 and put your old T7300 back in.
Then return it/try to get a refund for that bad T8100.

[eyeland]

Yes, I agree, that is the obvious suggestion
Care to share any less obvious thoughts?
Even if backtracking turns out to be the only viable solution, I'd still like to learn a bit more from this experience.
One thing that bugs me is the fact that I have to disconnect AC and battery in order for the machine to detect the AC (and perhaps to detect the battery as well since the machine is completely unresponsive untill power has been dis- and reconnected)
Is this the result of some standard failsafe mechanism?
And if so, what can trigger it? thermal events? Voltagerelated events?
Another thing curious fact is that while refusing to load any OS fully, the machine did get "halfways" and had no problem executing win repair utility.
I assume that we must be able to draw some basic conclusions from this?
I will probably ask the seller for a refund, but I'd like to be able to argue resonably for the fact that the CPU might be faulty (sold as tested and working) and furthermore, I'd like to rule out any other issues before thinking about ordering one next time I come across a good deal (after I finish using this machine for my dissertation
EDIT:

get proper AS5

By the way, do you strongly recommend AS5 over Artic Cooling Ceramique? The latter is non-conductive and for some reason much easier to come by at the foot of the mountains where I currently reside

[RealBlackStuff]

In all thermal paste comparison tests that I have seen, AS5 comes out first or second. Why change?
And a Penryn on a non-Penryn board (even with Middleton BIOS) is risky, to say the least.

[eyeland]

In all thermal paste comparison tests that I have seen, AS5 comes out first or second. Why change?

Because I can get Artic cooling ceramic from a shop tomorrow whereas AS5 will require a drive or waiting for maildelivery

[eyeland]

Waiting for AS5 to arive by mail, but I still need some explanations as to the whole sensor mess..
Unless your opinion is that the digital/analog sensor issue will never work? I am ok with faulty readings as long as I know they are faulty and as long as they don't cause my cpu to throttle down or shut down when it is not needed..
Reset the bios to defaults and did a bit of testing, TPfancontrol reported temps as high as 105C while bottom and exhaust remained cool to the touch.
Is it plausible that the cpu can reach temps like that locally without any other parts (including the heatsink) heating up or am I "only" dealing with a sensor issue?

[eyeland]

ok, tried all the hardware-shops in bike range to no avail.. guess highquality thermal paste can be a rare find her in the middle east
Still waiting for the Arctic MX4 that I ordered on the net.
While waiting I can't help but to keep trying different scenarios and constructing hypothesis.
Assuming that my machine is not running hot but still shuts down due to an erronious thermal sensor reading
And assuming that this does NOT normally happen to users with the same system board as mine
Then, what could theoretically be the cause of this??
And, yes, I am persistent and did not entirely admit defeat yet

[Binh]

eyeland
Because the CPU temperature is high while the output air is only warm, you have a bad thermal contact between CPU and heatsink. Someone on www.thinkpad-forum.de (in German) observed that his T8100 Penryn CPU is a bit lower (in height) than the Merom T7300 one, and that caused an unusual high CPU temperature.
I believe that your heatsink is not properly seat on the CPU crystall, try to reinstall it. I don’t think that the thermal grease is the main cause of the problem, because a bad grease leads to only 5-10 deg. higher temperature than the good one. And note that the Artic Silver product is no longer the best one in the thermal grease market.
Concerning the problem on AC power, I guess that with AC plug in, the CPU works in high performance mode and thus it temperature quickly goes beyond limit and thermal protection is triggered. May be the BIOS remembers thermal failure and you have to remove the battery to reset it.
In your place, I would try to play with some setting on BIOS in the Config → Power section, especially CPU speed step and Thermal management policy to see if the problem still occur on AC or not.

[eyeland]

T8100 Penryn CPU is a bit lower (in height) than the Merom T7300 one, and that caused an unusual high CPU temperature

Now THAT is usefull advice This seems to make sense indeed.
Last night I got similar advice on the notebookreview forum and I also saw the post on the german forum though my german is pretty rusty
Followingly and took the machine apart again and it does indeed seem that the my penryn is slightly lower than my merom. This time I fastened the heatsink better (the first time I was afraid to overtighten the screws and I only tightened them as much as I felt they where when I pulled out the merom.
After that it worked!! No more crazy readings, and so far, no crashes.
I am however, still running a little warmer than optimal I think( while writing this in crome on win balanced on battery, passively cooled in my lap, I seem to stabilize around 48-51C)
As soon as my Artic paste arives I will give it a try, but I am still concerned that I might need to play around with some copper sheet to reach optimal temps. As the paste I used was of the "white paint" kind, I don't know if it has a curing-time or not.