[SOLVED] DELL Latitude 3540 - Black screen after disabling Igpu on BIOS settings

[leocb]

EDIT: The issue is now solved, more details on post #8

Long story short: I've a unlock BIOS for a long time now (Link), no problem there, but in a attempt to force some of my programs on the Dedicated gpu, I disabled the -Integrated Graphics Card- on the -BIOS advanced video menu-
Then immediately after saving the settings and restarting, my screen went completely black (Not even the screen backlight is ON!)

Some info on the status now:
I can turn on the laptop, indicator lights come on, cpu fan starts normaly
Seems like I can't get into the BIOS settings and use it "blindly" (more on this bellow)
AFAIK Windows isn't loading either, as I can't hear the startup sound

What I've already tried and didn't work:
-Press F2 to enter the BIOS Settings -> F9 to "Factory reset" -> left arrow key to go to exit and save -> enter (it seems I can't even get into the BIOS Setting)
-Take the laptop apart, remove the CMOS battery, wait 15 minutes, put everything back

EDIT: I would like to add here: I did not just switch the primary display to the PEG, I -COMPLETELY- disabled the intel integrated graphics on the BIOS.

please help!
Thanks!

[milkybar1983]

Did exactly the same thing as you but with a lenovo. Its best to try and get a similar laptop and go through the bios keypresses at the same time as you need to get timings correct and sometimes theres extra prompts. Good luck

[leocb]

I forgot to mention that, when I attempted to do the "factory reset" I was using a friend's laptop to guide myself, and it didn't work
It seems like i can't even get to the BIOS setting with mine, to check that, I did a simple test:
when the BIOS setting are open, a simple tap on the power button shuts the laptop down, I had to hold down the power button on mine to turn it off... so... yeah

Did you managed to restore yours with this method? I could give it another try when I see my friend again.

TY for the suggestion tough

[milkybar1983]

Yes i managed to recover mine

[leocb]

I tried it again, I can't recover it with this method.. does anyone have another solution?

EDIT: After searching (A LOT) online and talking to a friend who did the same mistake, I've come to the conclusion that, software side, nothing can be done about this.
Only 2 options are left for me:
- Get another motherboard and replace the EEPROM chip (I can find some cheap broken MB here)
- Get a EEPROM Writer and rewrite the BIOS directly

both of these options are hardware oriented, winch I wouldn't like to mess with. If someone have a better solution, please do post here

Thanks everbody, i'll keep this post updated with the progress.

[leocb]

UPDATE: In one of my searches I found out Insyde BIOS's have a recovery mode (Link) but I couldn't make my laptop get in this mode no matter what, so, after a long afternoon, I've discovered that some DELL laptops use the "END" key as opposed to the "Win+B" combination to get in this mode, so now I can get my laptop in BIOS recovery mode, but I can't figure out what the BIOS file name should be in the USB flash drive

This post suggests using Andy's phoenix tools to get the recovery name, here is what the log says:

...
Finished Extracting
LZMA and Tiano module compression methods used
EFI / Insyde BIOS
Recovery filenames are: 

L3540.hd?
SLIC header found in 7E....

does that mean the filename should have the "?" question mark in the end?
I'm going to get a linux and rename it and try again as windows won't let me rename it with the "?", but so far i got nothing.

Here's the original DELL bios in case anyone needs to check again:
DELL Direct download

here's the list of names i've tried so far:

ME.hdr
ME.hd
ME.fd
ME.bin
L3540.hdr
L3540.hd
L3540.fd
L3540.bin
K19F110A.hdr
K19F110A.hd
K19F110A.fd
K19F110A.bin
bios.hdr
bios.hd
bios.fd
bios.bin

Any further help on this is very welcome!

[leocb]

Update:
After digging all over the place, I discovered that the file need to be named "L3540.hdr"
I'm trying that but it's not working:
- single file in USB flash drive -> connect to laptop usb
- do all the things -> laptop get into crisis recovery mode
- USB flash drive flashes (access) for around 10s then stop
- wait .... then wait some more....
- nothing

maybe I'm using the wrong file? here is what I'm trying to flash:
https://www.dropbox.com/s/cz079n7gitf5lgd/bios.bin?dl=0
(rename it to "L3540.hdr" then put it on USB stick)

please help

[leocb]

I'm very pleased to announce that I've managed to restore my laptop, as off right now, I'm writing this post on it!
Turns out the filename was correct, but the file itself was wrong! -More detais on this bellow

These were the steps i took, your mileage may vary:

[DELL Latitude 3540 Insyde BIOS Recovery]
Note: Nothing is shown on the laptop screen during the whole BIOS recovery!

1 - Download the bios flash utility from Dell's website: Link Here

2 - Do _NOT_ extract anything from the file you just downloaded, as MANY online tutorials tell you to, instead rename it to "L3540.hdr" - windows will whine about changing the file format, just ignore it. (in my case, I renamed "L3540A10.exe" to "L3540.hdr")

3 - Grab a less than 4GB flash drive and format it as fat32

4 - Copy the file you renamed in step 2 to the flash drive

5 - Put the flash drive on your laptop, any USB port should do the job

6 - Remove the AC power from your laptop, _HOLD_ the "END" key down, plug the power again (no need to remove the battery)

7 - The laptop should now power up automatically, without you pressing the power button. The laptop "power on LED" will start to blink, this indicates you're in the correct mode. You may release the "END" key now

8 - In a few seconds, your flash drive LED will light up (access), the laptop will look for the file on it, after 10 seconds or so it should find the file and the flash drive LED should stop, if not, the laptop didn't find the file. check step 2 and try again.

9 - If the laptop has found the file, and it is the correct one, you should start to hear a beep every two seconds, if not, the laptop have found the file, but it's not what he wants, check step 1 and try again.

10 - after 3 minutes or so, the beep pattern will change to 5 beeps in a row, this means the flashing procedure is done and your laptop should reboot automatically, if not you may hold down the power button and do it manually.

11 - Enjoy your recovered laptop!

Thanks to everyone who tried to help me, I'll post all of this on the tutorial section too, maybe it'll help someone somewhere