T23 Shutting off without warning

[HDRW]

(I did check the "T23 shutting off" thread - this is different as it has no correlation with plugging in a USB device)

My daily-use T23 has started shutting off suddenly, with absolutely no warning and no apparent reason.

It sits in a docking station with the lid shut all day, and three times now it has just died (with a "Clack" from the docking station (the locking solenoid?). I have been doing different things each time, and not touching the hardware. It doesn't report a fan error (I've had this before and replaced the CPU fan some time ago).

Afterwards it powers back up OK and seems not to have a problem - until the next sudden shut-off!

Any idea what could be causing this, and what I can do to stop it?

Cheers, Howard

[RealBlackStuff]

CPU overheating would be my number one choice.

[HDRW]

CPU overheating would be my number one choice.

Thanks for the reply. Can the CPU command an instant power-off if it thinks it's too hot? Do you know the recommended max. CPU temp?

I can feel some warm air coming out of the slot, so the fan must be running somewhat - but I suppose the CPU may not have good thermal contact with the heatsink - when I get some time I'll take it apart and re-paste it (I wish you didn't have to take it so far apart to get to the CPU!).

I presume running with the lid shut isn't a problem in itself? It's how I've been using this machine for years!

Cheers,
Howard

[RealBlackStuff]

Probably the thermal paste has dried out, and the fan exhaust is overpopulated with dust bunnies.
It needs a fan removal, then clean off all the old gunk from both fan and CPU with Isopropyl alcohol or similar,
then dust off/blow out the fan with e.g. compressed air. Stop the fan from rotatiting during this blow-out.
The reapply a good thermal paste sparingly (size of a rice corn, spread out with e.g. a credit card).
A T23 should not run hotter than maybe 65o C.

[HDRW]

Thanks again for the advice - the other oddity is that it has been randomly trying to go into Suspend, while I'm using it - the screen goes black and there's a muted beep or several, and on pressing a key it displays "System resuming..." and comes back again. I hope this is another symptom of an overheating CPU!

Anyway, I've just done the re-paste thing. The old paste was a grid of white dots, and they hadn't all spread to fill in the gaps between. I presume this is the factory-install condition, where the dots are on the heatsink and should spread when it's squished down, but in this case they didn't spread completely.

I've cleaned it all off and put on some nice silver-bearing goo, and given it a good press-and-wiggle to make sure it's properly spread. There was remarkably little dust in there - certainly not blocking anything, just a light coating in a few places. All clean now - fingers crossed that it was the problem!

I also replaced the hinge-cover and palm-rest plastics with those from my dead T23 - the ones on this had had a couple of the screw-bosses break loose some time ago, so now it's all as it should be again.

Cheers,
Howard

[rkawakami]

Thanks again for the advice - the other oddity is that it has been randomly trying to go into Suspend, while I'm using it - the screen goes black and there's a muted beep or several, and on pressing a key it displays "System resuming..." and comes back again. I hope this is another symptom of an overheating CPU!

Actually that sounds like a system that's going into and out of hibernation. It would have to be just the right set of circumstances for the system to shut down randomly like this. Here's what's possible:

- The lid switch is not operating properly; i.e., it does not recognize the fact that the lid is down
- The system has been set to go into hibernation mode when the lid is closed
- At some random point, either through movement, heat or whatever, the lid switch contact works as designed and sends the signal to the motherboard to hibernate the laptop

One easy way to verify this would be to go into the Power Options settings and check what the action is for when the lid is closed. If it's set to hibernate, then I would change it to "Do nothing".

[HDRW]

Ray,

Thanks for the suggestion, but I don't think it's what's happening - the first thing I do with a Thinkpad is turn off the lid-switch's suspend functions, as I usually use them lid-closed, via a KVM switch, and I never have Hibernation set on at all (I'd rather use the disk space for something else!). I've had this one for over five years, and I haven't changed any settings for ages. Oh, and it does respond to the lid open/close by blanking and redisplaying the video, so I think the switch is working OK.

Now I've done the re-pasting of the CPU, we'll see if it's solved either or both of the problems I've been seeing recently.

Cheers,
Howard