[Problem] Downgrading Dell G7 7590 BIOS (<1.9.0)

BIOS/UEFI Modding BIOS Modding Guides and Problems
1

Have tried everything under the sun to downgrade bios versions to allow for undervolting on my 9th gen i7-9750H, but Dell have blocked downgrades completely.

Have just ordered CH341A kit and am willing to do whatever necessary to disable CFG-Lock & Overclocking lock. I don’t mind what version of the bios I flash.

Completely new to this forum and bios modification in general but I have a couple of linux environments already if needed for the modification. Any help with this would be massively appreciated.


Edit by Fernando: Thread moved into the “BIOS Problems” Forum Category and title shortened

2

Read the guides, identify ICs and get their datasheet pdf.
Perform backups, do NOT erase/write without proper backups and verified data integrity.

[Guide] Using CH341A-based programmer to flash SPI EEPROM - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum

[Guide] Flash BIOS with CH341A programmer - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum

[Guide] How to Use a CH341A SPI Programmer/Flasher (with Pictures!) - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum

No board information ID provided but based on the laptop model this could be correct for now:

image
image1331×449 195 KB

3

why are you not using cvar commands when booted with grub on usb to unlock overclocking etc ?

CFG Lock
0x5C4 0x0

Overclocking Lock
0x660 0x0

OverClocking Feature:
0x72C 0x1

bootx64.zip (2.9 MB)

This file on an empty Stick using following folder structure :

EFI/BOOT/bootx64.efi (extracted File)

restart - F12 - boot from USB - command line = 3x entering those vlaues - reboot

at least they should be similar i guess…
If you link your UEFI Protocol or your Bios Dump i can check them quickly what the values on the G7 are to unlock Stuff..