[Request] I need help unlocking BIOS Insyde Dell Inspiron 15R SE 7520

I’m searching to flash the A14 update on my device, but the FD file has an expired signature and the manufacturer no longer supports the machine.
I’ve already tried different ways, including here on the forum the method Insyde H2O bios unlocking/flashing also without success, thank you to anyone Can you share the solution!

i sent you a message - posting here for visibility :

my personal experience with Dell firmware and setup_var (disabling SMI Lock, BIOS Lock, GPIO Lock, and enabling Me FW Image Re-Flash) has not worked.

see my process below for an inspiron 15:

follow Dell’s guide to create a bootable usb flash drive :
https://www.dell.com/support/kbdoc/en-us/000145519/how-to-create-a-bootable-usb-flash-drive-using-dell-diagnostic-deployment-package-dddp

copy your A14.EXE onto the drive. boot to USB storage device (do not select UEFI boot entry).
try and share your results:
A14.EXE
A14.EXE /forceit

edit: please share a screenshot/picture if you have trouble.

my next thought is trying the same bootable USB drive with the first/earliest available bios release with /forceit. my specific inspiron has an early bios version where Write Protection is disabled for bios region.

extract rom file from oem release , “A14.EXE /writeromfile”.

fptw (windows and match intel ME version) or flashrom (debian/ubu with iomem=relaxed).

WIN32\fptw -bios -rewrite -f A14.bin
sudo ./flashrom -p internal --ifd -i bios -w A14.bin

i think the setup_var does not work for my model because locks are defined in UEFI module PchSpiRuntime. anyways , please let me know if you have questions. (and share screenshot/pictures if trouble)