Thinkpad T440P bios repair after WIFI whitelist mod

[helpmepleasethanks]

As per the the rules, here are the specifications of my laptop :

• Make and model number : Thinkpad T440P
• Serial number (S/N) : PB-03A7V7
• Model type - Model (MTM) : 20AW-S2N800
• Bios version : 2.50 (not 100% sure, that's what I remember)

Here is the problem, and the events leading to it :

1. Upgrade screen, keyboard, trackpad, RAM and CPU
2. Reboot and use the laptop for a bit : everything is working fine
3. Shutdown (no power) and upgrade WIFI with unsupported chip (AX210)
4. Boot up the device : bios warning, as expected
5. Shutdown the device again (no power)
6. Connect the 8-pin clip of a CH341a external programmer to the Winbond W25Q32.V chip
7. Save two copies of the bios and confirm they are identical
8. Mod the bios to remove the WIFI whitelist following this guide : https://notthebe.ee/blog/removing-the-wifi-whitelist/
9. Flash the new bios
10. Problem : Power LED lights up, fan spins up and stops. After a few seconds, the power LED briefly flickers off and back on, and the fan spins up and stops again. No beeps, nothing is displayed. The cycle repeats until the battery or power cord is removed.

What I have tried to fix it :

1. Flash the original bios back : the problem remains the same.
2. Swap screen, keyboard, trackpad RAM, CPU and WIFI chip around : the problem remains the same.
3. Remove most components and boot with minimal setup : the problem remains the same.
4. Flash the original bios back multiple times : got a warning (Warning: Chip content is identical to the requested image), and the problem remains the same.
5. Disconnect CMOS battery and hold the power button to discharge the device : the problem remains the same.
6. Test with the switch (SW1) on and off : the problem remains the same.
7. Test wiith battery only, power cord only or both, the problem remains the same.

What I have found on this forum :

• Same issue, no fix : click
• Similar, fixed maybe? : click

The W25Q32.V is still responding and I can read from it and write to it.
Since I swapped every component and the behaviour remains the same, I think that either the motherboard is faulty, or the firmware somehow got corrupted.
I just don't understand how the motherboard would suddenly be faulty, when everything seems to have gone as expected when modifying the bios.
I have attached the original binary.

Thank you for your help, and don't hesitate to ask questions if you need more information.

[helpmepleasethanks]

Small update.

i have been playing around with the laptop, trying to setup coreboot to see if it might just fix it somehow. That meant I had to read the 8MB chip and combine both binaries into a rom file.
Using ifdtool, I tried validating and modifying the files, but it keeps returning various errors. It really looks like the bios is corrupted.

I have attached both files in this new zip attachments (4MB and 8MB).

Can anyone confirm if they are corrupted or not? Is it possible to repair it or generate a new bios from scratch using the information I provided?
I don't think the motherboard is faulty, I would like to save it. Please.

[Maik1974]

Hi and thanks for the link to this post.

Have you read and patched the 4 MB and 8 MB?

I have to admit that I have only patched the 4 MB chip so far and the 8 MB has not been processed yet.
I thought it would be particularly easy with the T440p because you can reach the chip very easily. I only realized last night that there is a second chip.

[helpmepleasethanks]

You only need to patch the 4MB chip if you want to keep the bios and remove the whitelist.
Coreboot replaces the bios and you need to replace both the 4MB and 8MB chip content.
I'm trying to give as much information as possible to get help, but I don't think the 8MB is the problem.
From what I understand, the bios is on the 4MB and I believe it got corrupted somehow.

[Maik1974]

T440p Type 20AW - S02A00 I found the T440p on the electronic trash where it clearly doesn't belong. Unfortunately a bios password was set which I wanted to fix with the patch. Do you think it makes sense to patch the 8 MB for this too? I can't imagine that this would change the error pattern.

[helpmepleasethanks]

I'm not sure... Next week I will look around the forum and try some bios and see if the behavior changes. I will report back.

[Maik1974]

When I read this post, the admin advises patching both chips.
I'll try it out over the next few days and report back.

https://www.badcaps.net/forum/troubl...thinkpad-t440p

[Maik1974]

Done!!!

Yesterday I tried to flash around 10 different BIOS versions (original and patched) that I found at Badcaps onto the 4 MB BIOS chip. Unfortunately, I always got the same error (see above). As I hadn't removed the motherboard up to that point, the 8 MB chip was untouched. As I had no other ideas, I removed the motherboard. Then I read the 8 MB chip and saved the file (twice). The file from the 8 MB chip could not be patched using the Lenovo Auto Patcher from Knucklegrumble. As there were two 8,192 KB files in the 10 failed attempts I tried before, I tried to flash this file onto the 8 MB chip. And that's exactly what worked. I have two files in the collection that are 8,192 KB in size. As I can't remember exactly which one I used, please try it yourself. I'm attaching the files for the 8 MB chip. I can't say exactly what type of file was on the 4 MB chip at that time. It must have been a patched version though, as I was guided through the individual steps to remove the password. I suspect that it doesn't matter what version is on the 4 MB chip. The problem is probably with the 8 MB chip. After I did that, I reinstalled my original 4 MB file. That's it ! helpmepleasethanks a quick response as to whether it worked for you would be nice. I'm fairly new to this area and am very happy to have found this forum. I think it's a very nice and interesting opportunity to work on a problem for free with people from all over the world on this platform. I've just donated a small amount to Badcaps via Paypal. Thank you for your great work. I hope to make a small contribution to this with this article.

[helpmepleasethanks]

I finally have time to update the thread. I had done similar steps before I even saw your post, and I actually had the same results.

1. Try flashing another bios (4MB) from the forum, did not change the behavior.
2. Try flashing the 8MB chip with the 20AN GLET68WW file, laptop came back to life.
3. Reboot many times, some beeps to begin with, until eventually nothing but a working laptop.
4. Flash back the original bios on the 4MB chip, still working.
5. Attempt to core boot with skulls, still working, and no alerts from the bios WIFI whitelist even when using the AX210.

I came to the same conclusion: somehow, the 8MB chip was corrupted or rendered invalid by flashing the 4MB chip.
Cheers, I hope you enjoy your T440P.