Does the cpu fan *actually work*, and or, is the radiator clogged with lint/dust?

Check whether the fresh thermal paste is making good contact with the CPU - those thermal pads were usually pretty thick and you might need to install a shim to get the CPU to contact the heatsink fully. I usually use thin copper sheet for that purpose.

Have you heard the fan run?

Little bit of a long shot: The T22 uses an ADP3421 chip to supply power. These are notorious for going bad, so I wouldn't rule it out in this case. Although these are mostly responsible for old Thinkpads not turning on at all anymore and just blinking their LEDs ("Blink of Death").

If nothing else helps and the CPU fan runs, swapping out the chip might fix it.

wierd_w wrote on 2025-04-04, 20:57:

Does the cpu fan *actually work*, and or, is the radiator clogged with lint/dust?

Yes, the fan is running - you can hear it when it’s on, and you can also feel airflow when the fan is spinning, although the air isn’t particularly warm. The heatsink looks clean, and the fan itself isn’t filthy either, but there is no kind of raditor. I wonder if this is normal for the T22 cooler:

Thermalwrong wrote on 2025-04-04, 22:22:

Check whether the fresh thermal paste is making good contact with the CPU - those thermal pads were usually pretty thick and you might need to install a shim to get the CPU to contact the heatsink fully. I usually use thin copper sheet for that purpose.

Have you heard the fan run?

I’ve checked that the thermal paste makes good contact with the die. You can feel some resistance when pulling on the heatsink. And when removing it, you can see that the paste is spread out well:

And yes, the fan is definitely spinning.

schmatzler wrote on 2025-04-04, 22:55:

Little bit of a long shot: The T22 uses an ADP3421 chip to supply power. These are notorious for going bad, so I wouldn't rule it out in this case. Although these are mostly responsible for old Thinkpads not turning on at all anymore and just blinking their LEDs ("Blink of Death").

If nothing else helps and the CPU fan runs, swapping out the chip might fix it.

I’ve also read about “BoD”, and found on https://thinkwiki.de/BoD (unfortunately only in German) that it can be fixed with a 2.2kOhm resistor. Besides that, the ADP3421 is still available on eBay.

Try a BIOS upgrade.
There is also another problem, without a working battery it won't allow BIOS upgrade. 😒

IDK if it has anything to do, just an idea.

Nexxen wrote on 2025-04-05, 19:37:

Try a BIOS upgrade.
There is also another problem, without a working battery it won't allow BIOS upgrade. 😒

IDK if it has anything to do, just an idea.

I have the feeling that the laptop just shuts down during updates and then won’t start up again.

Luckily, tomorrow I’ll be getting a second T22 for a good price (15 euros), although it has a broken case and a defective TFT. I’m hoping that in the worst-case scenario, I can swap the motherboard — and in the best case, just the CPU cooler.

User5518 wrote on 2025-04-05, 20:25:

I have the feeling that the laptop just shuts down during updates and then won’t start up again.

Luckily, tomorrow I’ll be getting a second T22 for a good price (15 euros), although it has a broken case and a defective TFT. I’m hoping that in the worst-case scenario, I can swap the motherboard — and in the best case, just the CPU cooler.

Is the tacho signal actually there? Maybe it isn't signalling and shuts down.
With the second you can probably troubleshoot it.
I'm interested as I have one 😀

Good luck, mate!

Good golly!! There is ENTIRELY too much thermal paste on that CPU!

You should put a RICE-GRAIN sized dollop in the center of the die, and not much more than that. If you glom it on like that, it becomes counterproductive.

User5518 wrote on 2025-04-05, 18:42:

I’ve also read about “BoD”, and found on https://thinkwiki.de/BoD (unfortunately only in German) that it can be fixed with a 2.2kOhm resistor.

That sometimes works if the chip is already degraded, but it's not a guarantee. I fixed an A22p a while ago and the resistor trick didn't work, it needed an entirely new chip.

wierd_w wrote on 2025-04-06, 07:42:

Good golly!! There is ENTIRELY too much thermal paste on that CPU!

You should put a RICE-GRAIN sized dollop in the center of the die, and not much more than that. If you glom it on like that, it becomes counterproductive.

I didn’t worry too much about the amount for now, but I’ll have to reapply the paste anyway and will use it more sparingly next time.

schmatzler wrote on 2025-04-06, 16:31:

User5518 wrote on 2025-04-05, 18:42:

I’ve also read about “BoD”, and found on https://thinkwiki.de/BoD (unfortunately only in German) that it can be fixed with a 2.2kOhm resistor.

That sometimes works if the chip is already degraded, but it's not a guarantee. I fixed an A22p a while ago and the resistor trick didn't work, it needed an entirely new chip.

Good to know, thanks. Since I now have a second T22 with a defective display and case, I’m going to swap out the entire board.

I received the second T22 today: the display shows some lines and the case is fairly badly damaged, but – it runs, and apparently runs stable. As a first step, I swapped the CPU cooler, but with the replacement cooler I noticed exactly the same issue. And what I clearly heard during the cooler test was a faint crackling sound on the board right as it shut off or went dark. Could be that there’s actually a problem with the display... I’ll test that next.

In the meantime, I’ve removed the 'faulty' board:

Next, I’ll first test the good display on the donor T22. If that works, I’ll fully disassemble the donor machine and install its board into the good chassis. (I made some videos showing how I remove and sort the screws so I can reverse the process later.)

A nice little project for a Sunday evening. 😉

Edit:
Just realized: I should’ve tested the T22 with an external monitor... because as I mentioned, after a few seconds or minutes the screen goes dark, there’s a crackling sound, but the LEDs stay on and the fan keeps running. Well, it's too late for that now — the board is out. All I can do at this point is test the display on the second T22.

wierd_w wrote on 2025-04-06, 07:42:

Good golly!! There is ENTIRELY too much thermal paste on that CPU!

You should put a RICE-GRAIN sized dollop in the center of the die, and not much more than that. If you glom it on like that, it becomes counterproductive.

I'm more amazed at the fact that even with that amount of paste, the die is not fully covered.

weedeewee wrote on 2025-04-06, 17:38:

wierd_w wrote on 2025-04-06, 07:42:

Good golly!! There is ENTIRELY too much thermal paste on that CPU!

You should put a RICE-GRAIN sized dollop in the center of the die, and not much more than that. If you glom it on like that, it becomes counterproductive.

I'm more amazed at the fact that even with that amount of paste, the die is not fully covered.

Yeah, I thought the same at first, but there’s actually a very thin layer over the 'bare' spot 😉

To make clear which T22 is which:

• T22_A => The first T22, where the screen turns off after a short time but otherwise appears to be fine.
• T22_A => The second T22, which has a display with lines and a heavily damaged case, but the mainboard runs fine.

So: Right now I’ve got the display from T22_A running on T22_B — and it’s been stable for over 8 minutes 😀

I’ll let the T22 run for 15 minutes now, and if it doesn’t shut down during that time, I’ll swap the board from T22_B into T22_A. That’ll give me one fully working T22 and one parts donor — all for a total of 40 euros.

Edit: The 15 minutes are up and the T22 is still running — the test was successful. Now I’m going to swap the board 😀

It's done! One T22 lives again – fully functional 😀

The second one is still in pieces for now:

I’ll probably reassemble it tomorrow and then put it on the stack of broken laptops.

@wierd_w I also fixed the thermal paste mess:

Big thanks to everyone involved for your ideas and input. I know that swapping the mainboard isn’t exactly a ‘real’ repair, but in my case, it was the simplest solution. I hope you’ll forgive me for that.