Lenovo Flex 14IWL Bios Editing Help

[grimacelord]

Hello,

I have a Lenovo Flex-14IWL here that I believe might be suffering from a corrupt BIOS. The device tries to power on, but black screen and no fan spin. The power LED then quickly turns off. I admit I am not 100% certain it's corrupt BIOS, but this is something relatively easy that I can rule out before I begin diagnosing board-level hardware problems. So far, I have:

1. I have saved the original (possibly corrupt) BIOS from the chip using a programmer. This file is 16,384KB in size and is in .BIN format.
2. I have extracted the BIOS image from the Lenovo BIOS update file downloaded from Lenovo's website here. This file is a .ROM image and is 18,093KB in size, or ~2MB larger than the original.

Here is where I am lost. The file sizes are different. I understand I need to edit using a hex editor, but honestly, I am not versed enough in this sort of thing. I'm not sure what I am supposed to be doing with the hex editor. Seems like I need to remove 2MB of data from the update to make it 16MB like the original, but I don't know how to determine what 2MB to remove. I'd really like to learn how to determine that myself, so if someone is willing to give me a hand with this, could you also spend a moment to explain exactly how it is you know what to edit? I'd appreciate that very much.

My ultimate goal here is to have a file I can flash back to the BIOS chip using my programmer and then see if this fixes my problem or not.

Attached are the two files I have prepared. The original BIOS file named original.zip and the extracted BIOS image from the downloaded update named EL4C1211.zip. I am hosting the files on my mediafire account.

Files:
original.zip
EL4C1211.zip

[grimacelord]

Re: Lenovo Flex 14IWL Bios Editing Help

Oh, crap. Can a mod move this to the BIOS requests section? I didn't see until after I posted. Ugh. Sorry!!!

[SMDFlea]

Re: Lenovo Flex 14IWL Bios Editing Help

Oh, crap. Can a mod move this to the BIOS requests section? I didn't see until after I posted. Ugh. Sorry!!!

Thread moved .

There`s a guide you can follow https://www.badcaps.net/forum/showthread.php?t=98038 .Its the same method to cut the bios to the right size. The same method for the DMI and win key ,the offsets in your bios are different though.Follow the guide but use the offsets below. D is the DMI, W is the key.

D 620000 - 6207FF

W A90000 - A9003F

If you followed it ok and made a new bios you can check its SHA-1 hash using Hxd. Analysis -> Checksums -> SHA-1 -> OK

0DF475F4267F8987509F29BC309B912820F89D9F .If its the same hash youve done a good job.
.

[grimacelord]

Re: Lenovo Flex 14IWL Bios Editing Help

Thread moved .

There`s a guide you can follow https://www.badcaps.net/forum/showthread.php?t=98038 .Its the same method to cut the bios to the right size. The same method for the DMI and win key ,the offsets in your bios are different though.Follow the guide but use the offsets below. D is the DMI, W is the key.

D 620000 - 6207FF

W A90000 - A9003F

If you followed it ok and made a new bios you can check its SHA-1 hash using Hxd. Analysis -> Checksums -> SHA-1 -> OK

0DF475F4267F8987509F29BC309B912820F89D9F .If its the same hash youve done a good job.
.

Nice, thanks!

I'll try this once I get to work later and come back to let you know how it went. Thanks again.

[grimacelord]

Re: Lenovo Flex 14IWL Bios Editing Help

Well, I followed everything twice and I am not getting that SHA-1 checksum you have. After two separate attempts, two different test bios files I made, I get the same checksum, but it isn't matching to yours.

The file that I end up with is indeed the same as the original backup, but the SHA-1 is different than what you posted.

I did try flashing it anyway and it doesn't appear to have made any difference in behavior at all. Now I'm not sure if that is due to the BIOS image I made being bad or if it never was a BIOS problem to begin with.

[SMDFlea]

Re: Lenovo Flex 14IWL Bios Editing Help

Well, I followed everything twice and I am not getting that SHA-1 checksum you have. After two separate attempts, two different test bios files I made, I get the same checksum, but it isn't matching to yours.

The file that I end up with is indeed the same as the original backup, but the SHA-1 is different than what you posted.

I did try flashing it anyway and it doesn't appear to have made any difference in behavior at all. Now I'm not sure if that is due to the BIOS image I made being bad or if it never was a BIOS problem to begin with.

Here`s one i made earlier .Compare it with the one you made .Flash it and if it doesn`t work i`d say the problem is somewhere else .If you need any more help with it just start a new thread in the main laptop forum https://www.badcaps.net/forum/forumdisplay.php?f=23

.

[grimacelord]

Re: Lenovo Flex 14IWL Bios Editing Help

Here`s one i made earlier .Compare it with the one you made .Flash it and if it doesn`t work i`d say the problem is somewhere else .If you need any more help with it just start a new thread in the main laptop forum https://www.badcaps.net/forum/forumdisplay.php?f=23

.

Awesome! It worked! I flashed your BIOS image and as soon as I pressed power and saw a fan spin, I knew it was going to be fixed. Of course, I waited for full boot and I can happily report that it is indeed working as expected.

So, I was right. It was a BIOS problem. Now I'm going to compare the bios files I made versus the one you made and see where I went wrong so I can try and learn more about this sort of this and try the next one by myself.

Thanks again for your help!

[Vesko356]

Re: Lenovo Flex 14IWL Bios Editing Help

0DF475F4267F8987509F29BC309B912820F89D9F .If its the same hash youve done a good job.
.

Well, I followed everything twice and I am not getting that SHA-1 checksum you have.

Here`s one i made earlier