Where is the BIOS chip on the T540p with the dGPU?

[qn7vvv]

My laptop's bios has been corrupted and nothing worked (fn+r, power drain, cmos reset). My last choice is using a ch341a programmer but I cannot find any info online about where I can find the bios chip, is probably on a different location on the dGPU variant. If anyone has any info, I would be grateful.

[RealBlackStuff]

Sign up and get the schematics here.

[qn7vvv]

Ok, I flashed the bios all good, the thing is the laptop is still not booting. It blinks 3 times when i put power and when I open it closes. What error would that indicate

[RealBlackStuff]

Begin with removing the battery, HDD/SSD, wifi card, WWAN-card/SSD (if there) and the RAM.
Try to boot, if it beeps 1-3-3-1, that is a good start.
Switch off, put only one RAM in and try to boot, if OK
Switch off, put that RAM in the other slot and try to boot, if OK
Repeat with only the other RAM, if OK
Switch off, put both RAMs in and try to boot, if OK
Switch off, put the HDD/SSD in and try to boot, if OK
Switch off, add wifi card and try to boot, if OK
Switch off, add WWAN card/SSD and try to boot, if OK
Let us know.

[qn7vvv]

I tried everything, but nothing worked. I tried different ram though, but only a single stick of 2gb ddr3 ram worked. Sometimes a single stick of the included ram would work, but not everytime. I am very confused. I also tried different ddr3l ram, but no luck. Also the single stick of ram that worked on the bottom slot (the black one) would not work on the slot above it (probably the slot's [censored], but it doesn't have any bent pins from what ive seen). If you know anything about that, I'd be happy to know.

P.S I have connected everything, disks wifi card both ssds.

[RealBlackStuff]

The RAM may be corroded.
Use an eraser to rub the gold contacts on both sides till they shine.
Remove the eraser leftovers with a small brush and do NOT touch the contacts.
Then try the RAM 1 by 1 as described above.

[qn7vvv]

The RAM may be corroded.
Use an eraser to rub the gold contacts on both sides till they shine.
Remove the eraser leftovers with a small brush and do NOT touch the contacts.
Then try the RAM 1 by 1 as described above.

Tried that no luck sadly. It's definitely not a ram issue from what I've understood, since the ram works on other machines. What I realized though is, the laptop runs only on single channel, debunking what I've said previously. Also side note, I realized that I flashed older bios, maybe making it the reason it won't boot up. The thing is I cannot find any guides on how I can update the bios, only with the windows app, which I cannot run on 2GB of ram + the bios doesn't have anyway to update it. Also the Fn+R key thing doesn't work for some reason. If there is any way I can get the latest BIOS on this machine, without taking it apart again, I'd be happy to know.

[RealBlackStuff]

Lots of BIOS here: https://pcsupport.lenovo.com/us/en/prod ... s/ds038147
The bootable CD-version (ISO) can also be 'burned' onto a USB stick with e.g. Rufus.

[qn7vvv]

Lots of BIOS here: https://pcsupport.lenovo.com/us/en/prod ... s/ds038147
The bootable CD-version (ISO) can also be 'burned' onto a USB stick with e.g. Rufus.

That's the problem. Rufus for some reason doesn't let me write this iso on a USB. I even took the .img from the ISO and wrote that, but it wouldn't boot. The problem is I have no other computer in order to install balenaEtcher (or atleast mine).

[RealBlackStuff]

FYI: an ISO can NOT be copied, it must be 'burned'.
Rufus is only for Windows.
Ask a friend to use their laptop to make you a CD or USB.

[qn7vvv]

FYI: an ISO can NOT be copied, it must be 'burned'.
Rufus is only for Windows.
Ask a friend to use their laptop to make you a CD or USB.

The thing is the iso on Lenovo's website is not bootable and doesn't have a partition table. I get an error on rufus that just doesn't allow me to 'burn' the ISO on my USB since it's not bootable. Also found an other computer and tried to do it via balenaEtcher but the stick is still not bootable. Am I doing something wrong or does Lenovo not have a bootable ISO image on their website xD

Update: I decided to flash a windows 7 iso on my stick, install the os, run the bios update from windows 7 and everything works like a charm! From what I understood is that when I got the laptop the BIOS were corrupted, then I installed an older version of the bios that would work only with single channel 2GB of ram? Then installed the latest version, and everything is good.

[RealBlackStuff]

Bit more complicated but here it is: https://forums.lenovo.com/topic/view/65/674677