Screen is flashing black

Question

MacBook Pro 13" Touch Bar 2018

{A1989 / EMC3214}—Released in July 2018, the 13" MacBook Pro features quad-core i5 and i7 processors and Intel Iris Plus integrated graphics.

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Nya Nya @nyanya

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crwdns2931729:0crwdne2931729:0: Nhl 9, 2025

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Screen is flashing black

Please refer to this for visuals.

Some weeks ago, my MacBook Pro 2018 (Touch Bar) started acting weird. I was back from the other place so I couldn't care about a single black-flash or two and watched some movies. However, it got worse when using those full-screen or heavy applications.

And I had to go to another country so I brought my other Laptop with me. But when I came back, I did some troubleshooting -

Ran in Safeboot
Ran in Recovery Mode
Reseted NVRAM and SMC or whatever
Wiped the entire disk and re-installed Sequoia
Downgraded to Ventura

All of those results in the same flashing black.

Then, I thought it was the cable since the disk was wiped clean and it was a fresh install. But however, whenever I'm running CleanMyMac and stuffs, it doesn't seem to do that thing. The same when watching live from Twitch or Youtube in full-screen mode.

So, I'm still confused if I should be reseating/replacing the cable.

But yes, tilting the lid and leaving it at about 45 degree (almost-close lid) seems to solve the problem but all I could do in that angle was press enters on terminal.

So my questions are

Is this a confirmed cable thing or is there any fix that I missed?
Is reseating/replacing cable doable by a non-Apple-tech? (I have experience with Windows Laptops but I'm afraid Macs would have different structure although I do know they will also have similar structures)

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score 0 · Answer 1 · 2025-10-09T05:23:38-07:00

Dan @danj

crwdns2934065:0crwdne2934065:0: 494.2crwdns2936485:0crwdne2936485:0

Self employed contract worker

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crwdns2931729:0crwdne2931729:0: Nhl 9, 2025

crwdns2933897:0crwdne2933897:0

Your display runs in a couple of different frequencies! The native is 2560 by 1600 at 227 ppi. But also supports scaled resolutions of 1680 by 1050, 1440 by 900, and 1024 by 640. Some Apps will force the system to jump to the lower resolutions which in turn lowers the scan frequency!

So what does this have to do with the screen flashing? What you are seeing is the T-CON clocking is messing up at a given frequency (2560 by1600) is what I'm suspecting. This often becomes an issue when running more process intensive Apps so the system is running hotter. You could see if boosting the fan helps but ideally I would want to monitor what's happening as it could be as simply doing some dust clean up and/or thermal paste refresh.

I find TG Pro is the best tool here, let's see what it tells us. With the system running but idle for a bit (no wink-out) take a snapshot of TG Pro's main screen showing the sensor listing (you'll need to slide the window to see the lower entries for a second snap) then when it's winking out repeat make sure to label the files and post them here so we can see them.

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It's actually the other way around. It blinks black when the CPU is idle and it not even once blinks when the CPU is under intensive tasks like scanning (CleanMyMac, Onyx, Magican). Even running `find .` on terminal will stop the screen from blinking black. So, the temperatures are also hard to capture because the fans won't even turn on and there will be two different behaviors. However, the terminal or the respective app needs to be the focus. If it's just run in the background, the screen would still blink.

crwdns2934271:0Nhl 9, 2025crwdnd2934271:0 Nya Nya crwdne2934271:0

@nyanya - Most Apps run at the lower resolutions. There are utilities which can force the resolution to prove things.

The top most App issue may be pointing to a graphics chip issue and its access to video RAM here a part of the main memory is used with the Intel Iris Plus Graphics services within the CPU chip.

crwdns2934271:0Nhl 9, 2025crwdnd2934271:0 Dan crwdne2934271:0

I've tried installing Windows 10 via Bootcamp Assistant and the blinking flash doesn't happen there as well. Now I'm thinking about downgrading the system into Monetary. I've also installed BetterDisplay and now trying to tweak things but no luck yet. I'm just hoping I don't need to get into hardware since it works in all other kinds of OSes.

crwdns2934271:0Nhl 9, 2025crwdnd2934271:0 Nya Nya crwdne2934271:0

@nyanya - Windows doesn't support the 2560 by 1600 at 227 ppi scan rate! And the last time I checked Linux doesn't either which supports the point on the T-CON having issues.

crwdns2934271:0Nhl 9, 2025crwdnd2934271:0 Dan crwdne2934271:0

I'm pretty bad on hardware stuffs. So, is replacing T-CON the only way? The black-blinking doesn't respond to temperature and fans, though. It happens regardless of that. Is there a way to change drivers or anything to mimic Linux/Windows' ones so this doesn't happen? The laptop is only used for light-weight tasks like Canva/Web-browsing/Movies.

crwdns2934271:0masiku 6 agoNhl 9, 2025crwdnd2934271:0 Nya Nya crwdne2934271:0

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