GPU Repair

This is a stub article describing some aspects of GPU repair. At first, this is gonna be only my "notes" page but i will try to keep it structured.

Main sources for the reliable GPU information ATM:

Techcemetry (patreon only discord, (YT Channel)

vlab.su - one of the most advanced Russian forums with hundreds of cases and pages.

DO NOT search this page for any sort of download links and proprietary NVIDIA/AMD Software. Everything is quite easy to look up in Google.

NVIDIA MATS / MODS (iMac with Nvidia GPU / MacBook Pro A1398 2012-2015)

This software is an advanced factory testing suite. There are different versions, "GOLD" files with different GPU parameters. Most recent and universal version atm is 455.127.

If you look up easymats0005 in Chinese internet/google, you will find usb stick generator software. For reasons described above, no link can be provided.

If you do not have output on screen and the last thing you see is "no suitable video mode found", edit grub.cfg:

if loadfont /boot/grub/unicode.pf2 ; then

set gfxmode=auto

insmod efi_gop

insmod efi_uga

insmod gfxterm

terminal_output gfxterm

fi

set gfxmode=auto

insmod efi_gop

insmod efi_uga

insmod gfxterm

terminal_output gfxterm

set menu_color_normal=white/black

set menu_color_highlight=black/light-gray

set timeout=0

menuentry "Start Linux" {

set gfxpayload=keep

linux /tiny/kernel quiet

initrd /tiny/initrd

}

GRUB_TERMINAL=console

There are multiple test scripts in this image, in most cases you can go to 455.127 folder and simply run "nb".

After test is done, results will be stores in results.txt. Use reboot / shutdown command to keep filesystem clean(if you simply shutdown, next time it will mount i read-only, there are no chkdsk tools in this tiny image)

channels identified by MATS results are accurate to the boardview positions.

for some advanced use, you can go with mods:

./mods gputest.js -oqa -old_gold -test 178 -fan_speed 70 -dramclk_percent 100 -ignore_fatal_errors -run_on_error -matsinfo

command is mostly self-explanatory. If MATS finds no issue with RAM but card works unstable under load, this might be an issue on higher frequency.

Please note: i