Display Issue - Horizontal blue lines in application windows

Last week my 14 month old 2019 MacBook Pro 16 with i9 Core started producing thin black horizontal lines 2 mm apart on my screen. Lines would vanish when screen was closed to a smaller angle (30 degrees) and then reappear, when opening wider. Also experienced occasions ghosting of images or overlapping app windows. Took the MBP 16 to the Apple Store for further diagnosis. Techs indicated that it could be a loose display cable. They offered to check for a possible loose display cable and re-seat it. If not resolved, said display would have to be replaced. For what it’s worth. (Apple offline and online diagnostics performed all indicated no other hardware problems, with the GPU, etc. yet... Problem seemed to be diagnosed. Attaching an external display is also helpful in diagnostic of the GPU, and external display was normal. Headed back to the Apple Store next week. Not at all pleased with this situation.

So, I thought it might be interesting to note that if I turn on my computer from being completely shut-down, at home, running a Thunderbolt 3 to MDP to DP chain of adaptors to a 27" Dell display, and to a USBC to USB3-HDMI-Ethernet dongle connected to another 24" Dell display, and keeping the laptop open (2019 MBP running Big Sur), the glitch will not appear. I can operate for days and not see it.

However, if I unmount my external drives, disconnect the dongles, and go mobile, using the laptop on battery, then go back home and reconnect to the dongles and try to work again from home, it happens 100% of the time. Fully reproducible. I need to then restart to get Chrome, Safari, WhatsApp to work without the graphics glitching again.

I have disabled the "Automatic graphics switching" and the behaviour continues.

My mainboard has been replaced. I have re-installed from a USB drive, from a web install, new account, no old setting, no old account corruption, and this happens.

It's not my mainboard, it's not a program I'm running that is exhibiting this behaviour on other computers, it's not my account, it's not my OS installation, it is clearly, undeniably, a fault with this model of computer that Apple seems to be unprepared to admit, should they be forced to recall them and replace them with an equivalent feature set laptop that doesn't do this.

[Edited by Moderator]

Thanks for providing the update, @ileradeltercomondo.

That is the worst of my fears – that potentially, this issue is inherently a hardware architecture and implementation fault that cannot be resolved in software without massively crippling the function of the GPU. I hope this can be proven otherwise from Apple. Something perhaps to do with how Apple integrated AMD's GPU core into this particular generation of Macbook Pros? It has been a nagging hunch that I've had for a while, especially seeing how we haven't gotten any fixes or updates from Apple.

It has officially been more than a year since this was reported. I am still abhorred at how I was led to think this was Google's fault in my initial Apple tech support outreach.

Those who continue to parrot resetting NVRAM or to disable hardware acceleration, keep drinking the Kool-aid. The rest of us here are looking for a resolution to getting our machines working – the way they were spec'ed and advertised to us – and that we depend on the stability of our machines to work when we expect them to.

My display continues to glitch. The easiest way to reproduce this is to leave the MBP plugged into a second display, let it go to sleep for a few hours while you have a web browser window (or any WebGL application) running, and wake it up. That said, I have also encountered the same glitch without a second display. The trigger point is almost always waking the computer from sleep – although these days just coding a WebGL app and testing it on browser refreshes can also trigger it.

Have there been sufficient fellow users who have submitted a tech support case to Apple, quoting this discussion?

To the Moderator: what did you edit in ileradeltercomondo's post? Some transparency will be useful here given the nature of this case.

The terms of the beta program are that you are not permitted to discuss the beta program's results in a public forum and that's what I said I was going to do, so that's a big no-no. I can't and will not now discuss how it's going the way I thought I was going to do. I have been rendered impotent in helping the people in this post with any updates on progress being made.

I'd like to echo user @chuank 's call to the moderator for some transparency with this problem. I think that this would be considered a very much appreciated and respected gesture of good will to the people who bought this products in good faith that they would work as described.

If it is an internal hardware issue, out of warranty it will be a challenge. I just had my 2020 MPB 16 repaired. It was a faulty internal display ribbon connecting the display to the logic board. Display had to be replaced because the cable is attached to the display screen. If you want assistance, you must work with the apple store, in hope of getting any financial assistance. Apple Care senior level support is of little assistance. I was not successful. Paid out of pocket because I mistakenly agreed to pay for the out of warranty work at the apple store, locally. You would need to protest the problem in the Apple store to get any assistance, if possible. There should be lemon laws for high end consumer hardware. I filed a complaint with apple/feedback per online apple care case worker phone service. Their quality of support is great. But their coverage of design flaws could be better.

Ha! I can empathise with the black hole. From my recent experience challenging a MBAir 2020 fault repair, much depends on the 'service' advisor's attitude.

Apple Store genius bartender went through with me what needed doing (a screen manufacture fault generating a silly pattern exactly matching a sample shown in his repair manual) and he sent the machine off. Three days later, the wonderful Ostrava (CZ) Repair Depot stated that the fault they found is different than originally specified, they reckoned user-damaged and therefore non-warranty. My choices were sending it straight back unrepaired/ pay Apple £450 UPFRONT for the repair/ discuss it with Apple support. I chose the latter - no way was Pegatron going to get away with a presumption that the customer - and indeed the genius bartender - is lying.

Adviser on webchat claimed that because the support centre is 'international' he had no access to region-based seniors for a couple of reasons that looked baloney to me. And he couldn't/ wouldn't give out contact details for me to do it myself.

Couple more days passed and the machine arrived back unrepaired anyway. Made a second webchat call to escalate this nonsense, and lo and behold: the adviser this time not only found a senior in the right place to deal with my case but he transferred my chat to him! Senior agreed that my challenge was valid and that Apple store must send it back to Pegatron with his instruction that repair is within warranty. That's now sorted, and I'm happy. But what a waste of time and what stress it caused me.

I wonder how many customers, likely out of desperation to get their only computer returned repaired ASAP, simply pay the 'ransom' rather than face the struggle and extra time taken to get such large sums properly justified or overturned?

Pretty certain that the problem being seen by the people in this forum thread is not a hardware fault per se, but a design flaw. An unforeseen incompatibility that now uncovered, is too hard to fix without designing a new combination of hardware and swapping out the computers with anyone that's bought one of these 2019 16" MacBook Pro models. Clearly, this would represent a PR disaster, a somewhat serious financial hit, and a lot of egg on a lot of faces.

This particular problem being discussed here has nothing to do with authorised service centre or Genius Bar staff. Nothing to do with support reps who are as blind to the real reason this is happening as the market is. Nothing to do with quality of manufacture.

A number of us who have seen this problem have had complete logic board replacements carried out by well-meaning, highly professional and ethical Genius Bar reps, only to find that the problem keeps happening.

Make no mistake. This is a minor scandal affecting a group of mostly unorganised consumers and one that a very large corporation with massive amounts of legal horsepower has already calculated the risks involved in ignoring the affected customers and decided that ignoring it is the most viable course of action.

Prove me wrong.

All understood, I get you. Linked to my recent 'experience', I wonder how long it will be before the Corporation stops clamming up, admits design error and does a recall for all machines in the affected batch....? And of course those who were fobbed off then forced at digital gunpoint to pay out-of-warranty should get their money back.

Here is what i did to fix the issue in Google Chrome on my MacookPro (BigSur):

1) Type chrome://flags in URL bar

2) Locate the entry "Hardware-accelerated video decode"

3) Make sure it is set to "Disable"

4) Locate the entry "Hardware-accelerated video encode"

5) Make sure it is set to "Disable"

6) Restart browser.

I fixed the issue by;

1) Type chrome://flags in URL bar

2) Locate the following entry "Metal"

3) Make sure it is set to "Enable"

4) Restart browser.

Hi Chauk,

you can also add

1. Brave Browser Version 1.16.72.
2. Notion.so Version 2.0.8 (2.0.8)

I also have this problem, on Chrome and Edge.

It happens on my brand new Macbook Pro 16".

MacOS Catalina Version 10.15.4

Brave: Version 1.9.72 Chromium: 81.0.4044.138 (Official Build) (64-bit)

Also on Whatsapp desktop application

MacBook Pro (16-inc, 2019), macOS 10.15.5, blue bars, once a month or so and nearly weekly restarts when I use it first thing in the morning.

Definitely not contained in Chrome, happened to me on Safari aswell. Apple has some answering to do. Can't believe it's happening on a 16" MacBook pro which costs a fair amount to say the least.