External monitor screen corrupt and flashing

Question

External monitor screen corrupt and flashing

Hey all-

I upgraded to High Sierra last week and ever since I did, my external monitor has become almost unusable. With my 2017 Retina MBP in clamshell mode and a 32" NEC PA322UHD hooked up via a USB-C to DisplayPort cable, the display has went completely wonky.

It’s hard to explain, so I’ll throw in some screenshots. I’m getting all kinds of odd "corruption" patterns all over the screen. The patterns are usually confined to a particular window, and they move WITH that window, including scrolling. You can see the pattern affecting a window behind another window. So it’s not hardware based (well it is, because it only affects an external monitor, not the MBP screen itself; so it could be tied to the GPU). I’m also getting entire screen flashes of color sometimes, in an on off pattern that continues indefinitely unless I interact with the mouse or keyboard. The corruption and flashing is also tied to your input. So the patterns move when you type or scroll sometimes.

Apple Support was of no use. They had me run a hardware diagnostic, then reset the NVRAM and PMC, and then ruled it a High Sierra bug with no beta fix or time table. The issue isn’t listed as a "known issue" either. So basically, I’m screwed.

Anyone else having this? Fixed?

Posted on Dec 15, 2017 8:06 AM

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Answer 1

Best reply

jegelie2

Level 1

18 points

Dec 20, 2017 11:21 AM in response to Justin Vanalstyne

It seems to me the dreaded faulty GPU problem. I had a late-2011 Macbook Pro, with the problems you describe. It is a very expensive dead paperweight now. It died just a week after the Apple Repair Extension Program closed on that model.
See MacBook Pro Repair Extension Program for Video Issues - Apple Support.
You might be eligible, but you have to be QUICK on that, as I suspect the program closes on 2013 models by the end of this year!

Never mind, I thought I read "2013 MBP" somewhere but your's is a 2017 model.

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Answer 2

Dec 18, 2017 9:07 AM in response to Justin Vanalstyne

Justin Vanalstyne wrote:

Hey all-

I upgraded to High Sierra last week and ever since I did, my external monitor has become almost unusable. With my 2017 Retina MBP in clamshell mode and a 32" NEC PA322UHD hooked up via a USB-C to DisplayPort cable, the display has went completely wonky.

....

Does it happen when not in clamshell mode?

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Answer 3

Dec 18, 2017 9:30 AM in response to woodmeister50

It does not. Definitely not with the external display unplugged. And I just tested using dual screens with the MBP open with the external monitor plugged in. I did not get any screen flashing or patterns.

I am not sure what this means. The patterns and flashing definitely seem to come and go. Sometimes it’s really bad and I can barely see the screen. Right now, after having switched the monitors around and went back to clamshell mode, there is no flashing or patterns either.

Infuriating, distracting, annoying, and downright wasting my time. You would think that after 2 major point updates that major hardware bugs like this would be fixed.

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Answer 4

Dec 18, 2017 8:55 AM in response to Justin Vanalstyne

And here’s a video (with me chatting to Apple Support about the issue… how fitting!):

MacOS High Sierra - External Display Problem - YouTube

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Answer 5

Dec 16, 2017 3:38 PM in response to Justin Vanalstyne

No one else is having this issue?!

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Answer 6

Dec 20, 2017 9:43 AM in response to Justin Vanalstyne

I take that back, I did get artifacting and patterns on my MBP screen today while in dual-screen mode. And then my computer hard froze 2x this morning. Super great day! Loving High Sierra! NOT.

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Answer 7

Dec 20, 2017 4:46 PM in response to jegelie2

Crap. Somehow I marked your answer as "solved" and I can’t unmark it now. And of course, in true Apple fashion, there is apparently no way to mark a question as unsolved again. 😠

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Answer 8

jegelie2

Level 1

18 points

Dec 20, 2017 9:47 PM in response to Justin Vanalstyne

Could not delete it either 😟

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