Macbook 2011 Radeon GPU Repair

The first thing you will need to do is make a small modification to the EFI.
The instructions below use Arch Linux and a strict Terminal environment.

::Note from the developer: There is a known issue with performing this Mod on High Sierra.  Apple changed the way the backlight is controlled on High Sierra, and upon waking from sleep the backlight will not turn on.  After much research and logic board probing the issue has been identified as a Pulse Width Modulated signal to the backlight controller not being started. An additional Hardware Mod is required for High Sierra. This mod is explained in the steps below. ::

You can permanently disable discrete graphics card following next steps:

1. Prepare a Bootable USB pendrive with a non GUI Linux

1.1 Download ArchLinux ISO

• You need a working computer for that and a spare CD/DVD/USB drive.
• Download the latest Arch Linux ISO image.
• Then you could either simply burn this ISO to CD/DVD (which later could be either inserted to MBP’s SuperDrive or External DVD Drive connected to MBP by two USB cables) or create a bootable USB.

1.2 Creating the bootable USB with the .iso

• First, you need to identify the USB device.
• Open /Applications/Utilities/Terminal in MacOS and list all storage devices:diskutil listYour USB device will appear as something like /dev/disk2 (external, physical). Verify that this is the device you want to erase by checking its name and size and then use its identifier for the commands below instead of /dev/diskX.
• A USB device is normally auto-mounted in macOS, and you have to unmount (not eject) it before block-writing to it with dd:diskutil unmountDisk /dev/diskX
• Now copy the ISO image file to the device. The dd command is similar to its Linux counterpart, but notice the ‘r’ before ‘disk’ for raw mode which makes the transfer much faster:sudo dd if=path/to/arch.iso of=/dev/rdiskX bs=1mAfter completion, macOS may complain that “The disk you inserted was not readable by this computer”. Select ‘Ignore’. The USB device will be bootable.

2. Use Linux to change EFI vars

2.1 Boot to it

• Insert this CD/DVD/USB to Macbook Pro, hold Option key (alt) while booting.
• Choose “EFI boot” (that is your bootable installation media).
• When the menu shows, press “e” key to edit the GRUB options of the Arch Linux archiso x86_64 UEFI CD menu entry while it is selected at the main screen, add nomodeset to the end of this line and press Enter.
• If everything is done correctly, you will find yourself at the Linux console! (It takes some time so be patient and wait for the prompt)

2.2 Clear existing EFI vars

Looks like efivarfs filesystem is mounted by default! So you can already cd /sys/firmware/efi/efivars and ls to explore this directory and see if there is a gpu-power-prefs-... variable (where … is UUID of this variable).

• If there is such a variable, its better to remove it with rm.rm gpu-power-prefs-…
• If you are getting the “operation not permitted” message while attempting to rm, it means that efivarfs has been mounted as read-only and you need to remount it with read-write permissions and try again:cd /
umount /sys/firmware/efi/efivars/
mount -t efivarfs rw /sys/firmware/efi/efivars/
cd /sys/firmware/efi/efivars/
rm gpu-power-prefs-…
• If this also fails (you still can’t erase the file), use chattr command to disable file immutability and then erase the file:chattr -i "gpu-power-prefs-…”
rm gpu-power-prefs-…

2.3 Create a new gpu-power-prefs-… file

`printf "x07x00x00x00x01x00x00x00" > /sys/firmware/efi/efivars/gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`

2.4 Add immutability to the gpu-power-prefs-… file

This chattr command is supposed to lock a file to make it accessible only by “superuser” – and so that, while booting, your EFI will have no chance to screw up your gpu-power-prefs-… variable under any circumstances

`chattr +i "/sys/firmware/efi/efivars/gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9"`

2.5 Unmount efivars and reboot

Change to the root directory to unmount efivars:

cd /
umount /sys/firmware/efi/efivars/

Guarantees that your EFI variables are flushed to efivarfs filesystem. Please unmount it safely before rebooting.

reboot

On this reboot it is essential that you boot once into safe mode (hold Shift throughout boot), and then choose shutdown(not restart) from the menu.

Do this safe boot with the R8911 resistor in place. Without this SAFE BOOT, the next steps may not work.

Do no more boots until you complete the next steps.

The safe boot clears OS level GPU preferences, that may interfere with the following process.

This will now cause your MacBook Pro to stop switching to the Radeon automatically, but it will still draw power, create heat, and be visible to the OS.

In some cases the software modification (automated or manual) is not enough to guarantee a stable and fast MacBook Pro. Due to the way the AMD GPU fails, it can cause some issues if still powered on. This will show as very slow boots, crashes, video glitches.

We discovered that simply removing 1 resistor will resolve this.

The resistor can also be replaced with a switch, in case you need to turn your radeon back on for any reason.

The placement of this resistor varies between logic board models.

The resistor in question is R8911 on the 17″ MBP and R8911 on the 15″ MBP
a 1 Ohm resistor that provides a current path to the ISL6263C DC to DC Converter.

This resistor controls power to the Voltage Regulator that provides the Core Voltage to the Radeon GPU. Simply put, no core voltage, no GPU.
You will find the resistor just to the right of a cooling fan (in the above orientation). It will be near the ISL Voltage converter chip. This is the chip we will be disabling. (see image for your model)

Just remove it. The preferred method is a professional reflow station, but an iron and a steady hand will get you where you need to be.  If you used flux to remove it (not needed), make sure you clean up with a little Alcohol or other suitable solvent.

That is basically it. Next time you boot up you will notice your GPU defect issue is gone, and you will no longer see the AMD GPU as installed hardware.

A small warning: This mod will not survive a NVRAM reset.  For this (and other security related) reasons, it is recommended that you set an EFI Password. This will make it impossible to accidentally reset your NVRAM. Just don’t ever forget this password. 

In the event that a NVRAM reset removes the EFI mod, contact us via email for a recovery procedure. We have a reliable procedure that takes seconds and works 100% of the time.

ADDITIONAL STEP FOR HIGH SIERRA

High Sierra requires an additional hardware mod.  This jumper wire is different between 15″ and 17″, both are shown below.  Without this mod, your screen WILL NOT turn on after going to sleep.  On the 15″ we just need to put a small jumper wire (enamel wire) between PIN 2 of R9704 and PIN 1 of C9711.   Logic board does not need to be removed for this step. Only bottom cover removed.

Possibly easier Jump for the 15″. Chose one jumper method, do not install both.

On the 17″ we will jump between a test point and R9202.