Is it okay to flash stock bios onto the motherboard's BIOS?

[AkaBukai]

Hi there,
I have a 14" Lenovo Laptop (Flex 5 14ALC05) which has a boot issue.
The little LED on the power button is flashing slowly and nothing happen.
This unit do not have any BIOS button cell battery so I tried many times draining the power but it is still not powering on.

So I decided to flash the BIOS using a cheap programmer.
And I was successfully able to read the content (exactly 16MB file) which BTW is a WINBOND 74m12jwsiq (according to the package inscription - but detected as W25Q128FW in the software - IMSProg on Linux)

I also downloaded the sotck BIOS from Lenovo site which came as a .exe file.
I followed a guide to extract the BIN from this file (as I'm still on Linux).
Here are the step I did:

• I first run a program called innoextract on the .exe file
• Then I opened the .cap file with a Hex editor
• I deleted data in the range 0x0-0x317
• I then extracted the data in the range 0x0-0x1000000 into a new file
• Saved it as .bin

Now both of my files (the one read from the chip and the one extracted from the lenovo website) are both exactly 16777216 bytes long.

Here is my question, before I mess up..

Is it okay if I just go ahead and flash/write that extracted file directly onto the chip on the motherboard?

Or do I need to copy/paste some data from the original BIOS onto the stock extracted file before writing to the chip?

[AkaBukai]

Hi there,
I tried to check using a diff tool.
And first I noticed that the first 48 bytes of the original bios are present on on the extracted one but starting at the 9th bytes..
So I guess I used the wrong offset to begin with.
So I did extracted again teh 16MB datat but starting this time at the 0x320 address (instead of 0x318).
Now I have the first ~330KB of data being the same.
For the rest of the files I have no clue if it's because of a different version of BIOS.
And if so, should I copy/paste over some data that will act as some kind of ID?

[AkaBukai]

I just checked on the Lenovo website and they are only providing the latest BIOS only which is fairly recent (January 2024) so I'm pretty sure the one I have in the unit is an older one.
So I'm not really able to compare with older versions (and not sure if it was something relevant to do anyway..)

[SMDFlea]

I just checked on the Lenovo website and they are only providing the latest BIOS only which is fairly recent (January 2024) so I'm pretty sure the one I have in the unit is an older one.
So I'm not really able to compare with older versions (and not sure if it was something relevant to do anyway..)

Post your original bios backup and laptop serial number in this thread and someone will post a working bios for you https://www.badcaps.net/forum/troubl...flex-5-14alc05

[AkaBukai]

Another little update!

So I just went ahead and tried flashing that extracted BIOS.
Something to note is that I did remove the SSD from the beginning.
And now the good news is that it boots up to the BIOS at least!
But the reason I wanted to ask here first showed up indeed.
All the relevant data are empty now.
Should I be worried?

Here is the BIOS:

[AkaBukai]

Post your original bios backup and laptop serial number in this thread and someone will post a working bios for you https://www.badcaps.net/forum/troubl...flex-5-14alc05

Hi SMDFlea and thanks for the reply..
Okay I will do.
Out of curisoity, what is the step to make it work there?
Is it something I can learn as well?

[mcplslg123]

These data are missing 'coz you did'nt copy dmi data from your backup to new bios.
Open your backup bios in hex editor and try searching "LENV".
The dmi data is encrypted along with win key.