Weird display issue with pattern of horizontal lines on MacBook Pro 15" A1398

[Peperonix]

Hi everyone,

I have a very weird display issue on a 15" MacBook Pro Retina A1398.
This MacBook had liquid damage. I got it for free and attempted to save it.

I looked at the motherboard under the stereomicroscope and cleaned it with isopropanol.
On the mainboard, one choke capacitor is rusted. Apart from that most components are visually fine.
The cleaning was done some time ago, but I remember there was very little verdigris if any.

Symptoms
=======
- MacBook powers on with the bell.
- Pattern with horizontal stripes on the screen, however the Apple logo is perfectly pictured, at least at the beginning ; then stome stripes overlay it.
- Running a live Linux from an USB flash drive partly works. The graphics get tiles four times vertically (like a mosaic) and the OS gets stucked at some point.
- Running Apple High Sierra installer from an USB flash drive partly works ; the installer gest stucked at some point.
- If removing screen and connecting in HDMI to an external screen, the HDMI signal is detected but unfortunately out of range of my WUXGA (1920x1200) screen.

Although I could not test if the problem remains on an external monitor, I assume the screen is OK and the problem coming from the motherboard.
Else, the operating system would go on and the output would likely autoadjust to the external screen resolution.

I also assume the LVDS is OK as it does not seem damaged.

To my opinion, the problem most likely comes from the GPU or the processor, and maybe the GPU's VRAM or some cache.
But the problem could also be located at the RAM chips.
Or some other defective component.

I wonder if the symptoms (please see attached pictures) are typical from some kind of failure.

This is a technical thread, not one about profitability or hardware alternatives. Thank you.

 

[phaZed]

GPU is borked. Prob not worth doing too much to a 10yo Mac.

 

[gadgetfixup]

Disable discreet graphics and run off Intel graphics.

AI solution because I don't feel like typing it all out. We do the hardware solution but whatever if you can save one from the landfill and get a couple more years out of it.

-------------------------------------

Yes, you can disable the discrete GPU on the 15" MacBook Pro Retina A1398, but it depends on your reason and the methods you use. Here are some scenarios and solutions:

---

1. Temporary GPU Switching via Software​

If your goal is to force the system to use only the integrated GPU:

gfxCardStatus App​

• This free tool allows you to manually switch between GPUs.
• Steps:
  1. Download and install gfxCardStatus from GitHub.
  2. Open the app and set it to "Integrated Only" mode.
  3. The app forces the MacBook to use the integrated Intel GPU instead of the discrete GPU.

Limitations: This is software-based, and if certain apps (like video editors) require the discrete GPU, they may not function properly.

---

2. Disable the Discrete GPU in macOS Recovery (Advanced/Hardware Issues)​

If your discrete GPU has failed or you want to disable it completely (e.g., to fix boot loops caused by GPU failure), you can modify the system to ignore the discrete GPU.

Steps:​

1. Boot into Recovery Mode:
   • Shut down your Mac.
   • Turn it on and hold Command + R until the Apple logo appears.
2. Access Terminal:
   • From the top menu, go to Utilities > Terminal.
3. Disable the Discrete GPU:
   • Enter the following commands:

   csrutil disable
   nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00

   • This disables the GPU preference at boot.
4. Reboot:
   • Restart your MacBook.
   • Your system will now ignore the discrete GPU and use only the integrated GPU.

---

3. Permanent GPU Disable via Hardware (For Hardware Faults)​

If the discrete GPU has failed (a common issue with older 15" MacBook Pros), you can permanently disable it by modifying the hardware.

• This requires expert knowledge, soldering, or logic board modifications to disconnect power to the GPU.
• If you're not experienced, consult a professional Apple repair technician.

---

Summary of Methods​

1. gfxCardStatus: Easiest for temporarily switching to the integrated GPU.
2. Recovery Mode Terminal Command: For persistent GPU disable in software.
3. Hardware Modification: Permanent solution for a faulty discrete GPU (requires professional help).

Let me know which method you'd like more details on or if you're troubleshooting a specific GPU issue!
Yes, you can disable the discrete GPU on the 15" MacBook Pro Retina A1398, but it depends on your reason and the methods you use. Here are some scenarios and solutions:

---

1. Temporary GPU Switching via Software​

If your goal is to force the system to use only the integrated GPU:

gfxCardStatus App​

• This free tool allows you to manually switch between GPUs.
• Steps:
  1. Download and install gfxCardStatus from GitHub.
  2. Open the app and set it to "Integrated Only" mode.
  3. The app forces the MacBook to use the integrated Intel GPU instead of the discrete GPU.

Limitations: This is software-based, and if certain apps (like video editors) require the discrete GPU, they may not function properly.

---

2. Disable the Discrete GPU in macOS Recovery (Advanced/Hardware Issues)​

If your discrete GPU has failed or you want to disable it completely (e.g., to fix boot loops caused by GPU failure), you can modify the system to ignore the discrete GPU.

Steps​

1. Boot into Recovery Mode:
   
   • Shut down your Mac.
   • Turn it on and hold Command + R until the Apple logo appears.
2. Access Terminal:
   
   • From the top menu, go to Utilities > Terminal.
3. Disable the Discrete GPU:
   
   • Enter the following commands:
   • csrutil disable<br>nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00<br>
   • This disables the GPU preference at boot.
4. Reboot:
   
   • Restart your MacBook.
   • Your system will now ignore the discrete GPU and use only the integrated GPU.

---

3. Permanent GPU Disable via Hardware (For Hardware Faults)​

If the discrete GPU has failed (a common issue with older 15" MacBook Pros), you can permanently disable it by modifying the hardware.

• This requires expert knowledge, soldering, or logic board modifications to disconnect power to the GPU.
• If you're not experienced, consult a professional Apple repair technician.

---

Summary of Methods​

1. gfxCardStatus: Easiest for temporarily switching to the integrated GPU.
2. Recovery Mode Terminal Command: For persistent GPU disable in software.
3. Hardware Modification: Permanent solution for a faulty discrete GPU (requires professional help).

Let me know which method you'd like more details on or if you're troubleshooting a specific GPU issue!

 

[Canadian Tech]

If you're getting the same issue on an external monitor than the logic board needs to be replaced. Probably not worth it on such an old MacBook

 

[NviGate Systems]

There is a guy his handle or nickname was dosdude I think, he wrote a firmware for affected models for the switching chip.

If you disable physically the GPU, it can cause issues on some systems and lead to instability. You basically have to solder to test points (and if you mess those up the board has to be removed and chip replaced as there is no other test points) and buy a license for software and reflash the chip and it will no longer use the defective GPU, but you lose the video out as that is tied to the GPU.