820-2915 replaced by apple turned off GPU

Dozer

Member
Hi,
I have here a late 2011 untouched Mainboard. Customer told me he had problems with the GPU and they switched off the gpu. of course a external moniotor is not possible and preferences shows only intel gpu.

Machine is working good, the rotating donat is showing up as well.

I want now to replace the GPU by a good one. So can me send someone a good clear me BIOS?

I load up the "original" bios. By starting with the ALT-Key its needfull to enter a password, the password is "gpu"

Can someone explain me that thing? what they did with the bios?

the bios file you can download here : https://drive.google.com/open?id=1PirfNkIACQ-ctVw-OKiCuCgZDF4G1pWj

Regards
Uwe.
 

Dozer

Member
so, by replacing R8911 the gpu is already to see in the preferences,
found a clear me bios but it shows up a lock, going to remove the password now
 

Dozer

Member
ok, so now external is working, password is removed and i get starting up after a while th good old white screen of death, lets look now after gpu replace
 

2informaticos

Administrator
Staff member
Was GPU disabled in BIOS?
In such case, dGPU is enabled again (if good) doing PRAM reset.
They probably put EFI password, to avoid accidental PRAM reset.

Do you get image on both internal and external screen?
 

Dozer

Member
was no external screen, after flashing new bios i had external screen

wich ttol to use for such modification in bios?
 

2informaticos

Administrator
Staff member
Medusa programmer can disable GPU in BIOS.
But GPU power supply must be disabled; removing one of R8910/11.
 

Dozer

Member
I pulled of the GPU
Working good.

1) Is it possible to enable still the possible of brightness control?
2) is it without GPU still neefull to protect with password an accidentical PRAM reset?
 

2informaticos

Administrator
Staff member
BIOS mod should be protected against PRAM reset.
You can get into black screen once PRAM reset is done.
You can use QuickShade to control backlight via software.
If you get problems when close/open lid, may need to set BKLT_PWM to 3V, via hardware.
 
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