Any chance to extract my y540 bios dmi info from corrupted bios backup?

[dlhxr]

Hi, I am a Legion Y540 user and I bricked my laptop downgrading from 41ww bios to 26ww, which was definitely Lenovo's fault.

But I bought a ch3341a programmer. After backing up the corrupted bios, I flashed the stock bios successfully, but it turned out many motherboard variables are missing.

Then I found a tool called LVAR by lenovo and wrote most of the dmi variables back refering to my original box and labels on my laptop, including product name, mtm number, sn, etc..

But for other variables, it's really hard to know the original value.

Is it possible to extract UUID and my oem win10 license info from old backup?

Here's my corrupted bios backup. Thank you!

[dlhxr]

Re: Any chance to extract my y540 bios dmi info from corrupted bios backup?

Never mind. I solved it.

Using UEFITool to open backup image file and found an padding area at the start of bios region, which is from 60000 to 6CCFFF. After comparing with official bios image, this padding area should be DMI info area.

So I replace with the padding area and flashed it into bios chip by ch341a, then I got my dmi info back, including uuid, win10 license, sn, etc...

Hope it would help if anyone else encountered the same problem.

[duffyy]

Re: Any chance to extract my y540 bios dmi info from corrupted bios backup?

hello, could you give me more information, I had the same problem .. I sent it to a technician to do it but he didn’t put the information I’ll buy ch341a and put the information

[dlhxr]

Re: Any chance to extract my y540 bios dmi info from corrupted bios backup?

hello, could you give me more information, I had the same problem .. I sent it to a technician to do it but he didn’t put the information I’ll buy ch341a and put the information

1. Use Ch341a to backup the bios file.
2. Use UEFI tool to open backup file and the official bios file extracted by https://github.com/LongSoft/InsydeImageExtractor
3. Compare the padding areas to see which part is different.
4. Try analyze the different parts to decide where the DMI info is.

But if the techinician didn't help you backup and flashed bios already with empty DMI info. There's nothing you can do. Try LVAR if your pc is from lenovo as well. Find LVAR yourself please.

[Arsys]

Re: Any chance to extract my y540 bios dmi info from corrupted bios backup?

Hi i have the same problem with the DMI just flashed 38ww after downgrading then not booting.
My question is ...if i update bios normaly from vantage from 38ww to 41ww will i brake the laptop again? will i regain the DMI info after update?

[titmos]

Re: Any chance to extract my y540 bios dmi info from corrupted bios backup?

1. Use Ch341a to backup the bios file.
2. Use UEFI tool to open backup file and the official bios file extracted by https://github.com/LongSoft/InsydeImageExtractor
3. Compare the padding areas to see which part is different.
4. Try analyze the different parts to decide where the DMI info is.

But if the techinician didn't help you backup and flashed bios already with empty DMI info. There's nothing you can do. Try LVAR if your pc is from lenovo as well. Find LVAR yourself please.

thanks,