MacBook Pro screen flickering when monitor is connected

I have a 15.4" macbook pro vega20. When I plug my monitor into my computer, the screen on the macbookpro itself blinks. Any answers to why this is?

MacBook Pro 15”, macOS 10.15

Posted on Jul 15, 2020 6:53 AM

Similar questions

Just got the 27" studio display. Terrible flicker I just purchased the 27" studio display to connect to my 2021 MacBook Pro. I started editing an image in Photoshop and terrible flickering. Sometimes a dark grey band goes across the image. The flickering is happening every few seconds. thank you for any help
3335 5
Using Samsung S27A80 external monitor(s) with 2019 MacBook Pro I have two Samsung S27A80*U monitors. I have attached them to my 2019 16" MacBook Pro using USB-C 3.1 cables. When I have two monitors attached, the MacBook frequently freezes, flashes vertical lines on the main monitor, then crashes back to the login screen. If I detach one monitor, then it stops crashing, but frequently freezes. It becomes pretty much unusable. Once I have all external monitors detached, the computer behaves normally. Has anyone else had experience with this issue? Is there something I'm doing wrong? Should I upgrade the cables (these are the USB-C cables that came with the monitors)? Am I SOL with these particular monitors? They're listed as Mac compatible. Thanks.
2687 3
Internal display not detected Okay so I put my laptop to sleep and when I opened it again my macbook won't detect internal display, I attached a hdmi cable and it worked perfectly (on the external screen). I'm not sure why my internal screen isn't visible. I performed multiple operations to fix it. Hard reset, installed mac OS again. Everything. Nothing worked. I rebooted to safe mode and the screen came but it was faulty (attached a pic). Can anyone tell me how to fix this?
7110 12

1 reply

Jul 15, 2020 7:47 AM in response to Bulldog1019

If it blinks three times or less within five seconds and is done, that is a signal to you that an external display is connecting. It should be read as if the message" Attention, an External display has been recognized and is being enabled" was shown on the built-in display.

If something else, please describe the behavior more fully.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

MacBook Pro screen flickering when monitor is connected

Welcome to Apple Support Community

A forum where Apple customers help each other with their products. Get started with your Apple Account.

Learn more Sign up