Working on a MacBook 16-inch for a couple of month. Some weeks ago i started using an [Apple power extension cable]( https://www.apple.com/shop/product/MK122LL/A/power-adapter-extension-cable) - just for a couple of hours.

While working with MBP I saw a couple times it would turn the display off and on for one second or less (just like one very short blink that turns display fully off and on).

Just one, but like, once a day.

I thought it could be because of the power adapter extension. I never used it so I returned to using the MBP's direct power adapter without the extension.

I have been working without extension for a couple of weeks and it was fine except today. I saw one blink again, without any extension.

So I'm just curious (and a bit nervous because i can't go outside), is this some kind of static electricity that turns the display off and on for a second or is it a hardware or software problem?

It happens quite rarely but makes me write this question.

  • A faulty cable/power adapter would affect the entire laptop, not just the display. As for what could cause the issue, there are number of existing questions/answers that address it. I suggest monitoring it a bit more to see if you can correlate it to a specific action/activity.
    – Allan
    Apr 22, 2020 at 13:09
  • @Max Lukin I would try resetting the NVRAM and a hardware diagnostic test. Check out: support.apple.com/en-us/HT204063 and support.apple.com/en-us/HT202731
    – Todd
    Apr 22, 2020 at 17:01

1 Answer 1


For any power related issues with a Mac I would recommend you try one time an SMC reset: https://support.apple.com/en-us/HT201295. As Apple puts it: “Resetting the system management controller (SMC) can resolve certain issues related to power, battery, and other features.”

If that procedure doesn’t fix your issue you might want to have Apple technicians run deeper tests on your hardware by booking a service appointment.

  • Did it + hardware diagnostic. I hope it will work! Thanks!
    – Max Lukin
    Apr 26, 2020 at 18:38

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .