Permanently Disable 2011 15"/17" MacBook Pro Dedicated GPU - gMux IC Bypass

Discussion in 'MacBook Pro' started by dosdude1, Aug 25, 2018.

  1. _Kiki_ macrumors 6502a

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    Aug 13, 2017
    #76
    actually I had this model and GPU failed
     
  2. dosdude1 thread starter macrumors 68000

    dosdude1

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    Feb 16, 2012
    #77
    Nope, that does not happen. If you stopped getting video, it's due to bad solder joints on the GPU VCORE regulator IC (U8900).
     
  3. AdamMagus macrumors newbie

    AdamMagus

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    Nov 13, 2018
    #78
    Ok, I might wait for that. Looks like a cleaner solution.
     
  4. raileanu, Nov 14, 2018
    Last edited: Nov 14, 2018

    raileanu macrumors newbie

    raileanu

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    #79
    Hello dosdude1.

    First off all a big respect and thank you for your great work.

    I also start experimenting a while ago some EFI modes to disable the GPU on these 2011/2012 Mac's but never completed the work as I often get very busy with different IT work. It should be some instruction there on how to dictate to the computer to work in order to disable the dedicated GPU. I have knowledge and vast experience of working with EEPROM programmers and Hex editors etc and I found many solutions so far for many computers password mods etc and also with hardware which is my speciality and my preferred field.
    I come across today of a 820-2915-A with apparently an EFI mod only, which made the computer to work only with Intel. I was not aware of that and I reset the PRAM before dismantling the computer and see that had missing the AMD chip from the board and the EEPROM chip was re-soldered. Nothing more was modified on the motherboard. Of course it stop showing display after the PRAM reset. As the EEPROM was re-soldered I believe it had some modified firmware. I think was done with your instruction here http://dosdude1.com/gpudisable/ while the computer still had an AMD fitted. Unfortunately I have not done a dump of the chip before that. Also the AMD circuits are badly damage by who took it out so no way I can fit another one.
    I ask you, is there any way you can provide a dump for this motherboard where that procedure was done already and no PRAM reset effectuated in order to revive this computer and take it from there please?
    It can have a non clean ME Region I don't mind.
    I want to try the EFI solution without soldering the LVDS switch chip.
    Thank you so much in advance.
     
  5. _Kiki_ macrumors 6502a

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    Aug 13, 2017
    #80
    no, vcore was fine, GPU was working for several seconds, after that no image but laptop still was working
     
  6. dosdude1 thread starter macrumors 68000

    dosdude1

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    Feb 16, 2012
    #81
    Yeah, that's VCORE regulator. It's intermittent, and failed simply due to bad solder joints. Removing the IC, adding new good solder, and soldering it back on will fix the machine.
     
  7. _Kiki_ macrumors 6502a

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    Aug 13, 2017
    #82
    vcore gpu chip was replaced
     
  8. dosdude1 thread starter macrumors 68000

    dosdude1

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    Feb 16, 2012
    #83
    Probably bad hall effect sensor, then. The system probably thinks the lid is closed all the time.
     
  9. _Kiki_ macrumors 6502a

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    Aug 13, 2017
    #84
    how it's possible, where is connection? OS was working fine (youtube , safari) until heavy load for dgpu like games
     
  10. raileanu macrumors newbie

    raileanu

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    #85
    Hello dosdude1
    Did you had a chance to look at my previous post?
     
  11. dosdude1 thread starter macrumors 68000

    dosdude1

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    Feb 16, 2012
    #86
    I don't recommend you mess around with these temporary NVRAM/EFI variables to disable your dedicated GPU. My best recommendation is to just disable the dGPU permanently via hardware, as I explain in the OP of this thread, ESPECIALLY since your dGPU chip is completely missing.
     
  12. raileanu, Nov 14, 2018
    Last edited: Nov 14, 2018

    raileanu macrumors newbie

    raileanu

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    #87
    OK, thank you for your reply.
    But you have that dump anyway please?
    Is ok, I can "mess" with EFI as I done many times before, I know what I am ding, but will help a bit if you have a working temporary Intel GPU dump please to take it from there.
     
  13. dosdude1 thread starter macrumors 68000

    dosdude1

    Joined:
    Feb 16, 2012
    #88
    It's not necessary, you can just do it blindly (I've done it before). Just hold down the Command and S keys at startup, wait about a minute, then enter the following:
    Code:
    nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00
    and press Return.

    Then, type "reboot" and press Return. When the system starts back up, you should have video again.
     
  14. raileanu macrumors newbie

    raileanu

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    Nov 14, 2018
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    #89
    OK Many Thanks once again. I will try this and get back to you.
    --- Post Merged, Nov 14, 2018 ---
    Thank You dosdude1. You are a star!!! It worked.
    I will try to see now if there is any way that the EFI can be modified on Hex Editor to stay like that even after PRAM reset.
    I will keep you all updated.
     
  15. raileanu macrumors newbie

    raileanu

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    #90
    YES. I fund the permanent solution even if you reset PRAM. The trick is with the hardware id on hex. It took me almost 72 hours but is done and tested. I will share the solution here by tomorrow as to much tired now. I hope you dosdude1 to be agree. First I will wait for your consent.
    --- Post Merged, Nov 14, 2018 ---
    Also can be done a simple jumper to fix the screen brightness by commanding the keyboard brightness with that hardware LVDS permanent jumpers.
     
  16. LogoiLab macrumors newbie

    LogoiLab

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    Nov 14, 2018
    #91
    Hello raileanu,

    I'm the co-creator of the DyingLight mod with dosdude1.

    I'm glad you got the hardware mod working. For fixing the brightness controls you will need to perform the install for a DyingLight module. You can read about that module here: https://computeco.de/DyingLight.html
     
  17. raileanu macrumors newbie

    raileanu

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    #92
    Thank but I know this already. What I was saying is that can be done only with a jumper. But yes great work you all did there and very much respect.
     
  18. LogoiLab macrumors newbie

    LogoiLab

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    Nov 14, 2018
    #93

    This is not possible. You need a constantly applied PWM signal for the backlight IC. Or just straight 3.3v (which is still a PWM signal).
     
  19. raileanu macrumors newbie

    raileanu

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    Nov 14, 2018
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    #94
    Can I send you the mod privately? Keep in mind that will work but with another level control on the keyboard. You'll see
     
  20. LogoiLab macrumors newbie

    LogoiLab

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    Nov 14, 2018
    #95
    PM it to dosdude1
     
  21. Matejh macrumors newbie

    Matejh

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    Jul 5, 2014
    #96
    Please share your solution...
     
  22. dosdude1 thread starter macrumors 68000

    dosdude1

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    Feb 16, 2012
    #97
    We have analyzed this "solution", and found that it is not possible, for multiple reasons. First, the main reason is that the PWM signal for the keyboard backlight runs at a much lower frequency than the one the backlight IC (LP8550) needs, so this alone would make it not work. To add to this, though, the keyboard backlight is only on when the OS finishes booting, meaning that if it did produce the correct frequency PWM signal, the backlight would not even come on until the machine had finished loading the OS. Lastly, the keyboard backlight brightness changes inversely to that of the LCD backlight, meaning that it gets dimmer in brighter environments, and brighter in darker environments. There is definitely no possible way to control the LCD backlight brightness using the PWM signal for the keyboard backlight.
     
  23. Mrwinston macrumors newbie

    Mrwinston

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    Nov 17, 2018
    #98
    Replying to follow this progress.

    Also if anyone has a permanent solution of for the GPU fix WITHOUT soldering that allows PRAM/NVRAM reset and working backlight control in High Sierra and higher like Mojave that would be great.. if so, please let me know :).

    Working on Sierra with R8911 resistor removed and a special USB Ubuntu bootable that modded the EFI. All works like a charm but looking for a solution as described above.

    Im cool with software solutions but soldering brings some higher skills and equipment with it that I don’t have (yet)...
     
  24. dosdude1 thread starter macrumors 68000

    dosdude1

    Joined:
    Feb 16, 2012
    #99
    Unfortunately, it is physically impossible to permanently disable the dGPU without soldering. However, I am in the process of creating a drop-in board, that makes the soldering process much easier.
     
  25. Mrwinston macrumors newbie

    Mrwinston

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    Nov 17, 2018
    #100
    Cant wait to see the board! Saw a picture above here somewhere. Love how this process is going. A looooooot of still very good macbooks out there dusting away...
     

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