Screen Glitch at bottom of display

[pizzacommander]

I'm experiencing an intermittent screen glitch/"hiccup" at the bottom of my mid 2015 MacBook Pro's display, every 4 seconds. Looks as though the top menu bar is what keeps popping up for a millisecond or so-

Video here: https://www.dropbox.com/s/bjqxezfm90qie77/20180913_231620.mp4?dl=0

I've done some troubleshooting based on similar topics here. This is what I've already tried to fix the issue:

• Power off + restart
• Updated OS and any frequently-running apps
  
• Turned off "Auto Graphics Switching" in Energy Saver Prefs
• Reset the SMC
• Ran an Apple Diagnostic, no issues discovered

Current system specs below:

• MacBook Pro (Retina, 15 inch, Mid 2015)
  
• High Sierra 10.13.6
• 2.5Ghz Intel Core i7
• 16GB 1600 MHz DDR3 RAM
• Only connected peripheral is the occasional Lacie Rugged drive

While this happens most of the time, it occasionally stops when not connected to the power charger. Maybe there's a correlation? Anyone else having this issue?

 

[cruisin]

Make a new user account. Does the problem go away?

If you use the gfxCardStatus app you can force a specific graphics card. Do both have the problem?

If you reboot, how quickly does it come back? Are the times approximately consistent over multiple reboots? And if you reboot on a fully charged battery and use the machine on battery does the problem exist?

Do you have another power brick or know someone with another to test or a Apple store nearby (they should let you borrow theirs for testing or at least give a diagnosis)?

Do you have Bootcamp (and does the issue continue there)?

If you have a empty hard drive you can install macOS on it and boot from it (holding the option key on startup). This should narrow down the problem to either hardware or software as it will be a fresh install (and not ruin your existing install).

Hope that gives you some help.

 

[pizzacommander]

Thanks for your suggestions cruisin, I tried a brand new charger as well as creating a new user and the issue still persists despite these attempts. I don't have bootcamp, but will try a boot from an external HD.

Let me know if you have any other suggestions in the meantime, thanks!

 

[pizzacommander]

Few more updates:

• gfxCardStatus toggling did not affect anything
• I ran a new Apple Diagnostic with the new charger, still completes as "No Problems Found"
• I'm still trying to find patterns in the glitch, though I've noticed that if it is not flickering, it quickly begins to (sometimes immediately) when I plug in the charger

Will try bootcamp and an external drive fresh install and report back, thanks again for your suggestions

 

[cruisin]

If it doesn't happen on battery, and a new charger doesn't change anything, perhaps it is a ground/earth issue? Do you use a 3 prong (with ground) plug for the charger? For example, the North American version only uses 2 prongs and you need to use the extension to get ground.

Also, what happens when you use a different outlet in your house or better yet an entirely different location (work, friends house, etc).

See: https://apple.stackexchange.com/que...that-my-macbook-air-is-passing-me-electricity

 

[pizzacommander]

Unfortunately the charger is grounded (3-prong) and this issue persists in multiple locations/outlets/wifi networks. Trying the drive-boot this weekend, will report back. Thanks again for your help!

 

[pizzacommander]

I did a boot from an external drive (fresh install) and unfortunately the problem still persists. I'm really hoping this isn't hardware-related - any other tests I can try on the software side before I resign myself to a physical fix?

Again, really appreciate the help!

 

[cruisin]

A new power supply and location rules out power issues, while gfxCardStatus shows that it happens on both cards (or is unrelated to a graphics card). A fresh install doesn't change anything so that should rule out software. All this points to a internal hardware problem. In the unlikely event it will change anything, you can also reset the PRAM (unlikely to do anything but nothing to lose).

As a curiosity, what happens on a external monitor while your main screen is glitching?

If you can locate an Apple store they will at least give you a free diagnosis (and how much money they want for a fix). Good luck, your problem sounds expensive.

 

[pizzacommander]

Thanks again cruisin, will let you know how it goes!

 

[pizzacommander]

I just connected my laptop to two different displays - one via AirPlay mirroring, and another to a hard-wired external display. The problem did not appear on either monitor, which leads me to believe it's a physical hardware issue on my laptop's display...