Thunderbolt Display flickering on MacBook Pro but not old MacBook Air running Sierra

Question

Level 1

4 points

Thunderbolt Display flickering on MacBook Pro but not old MacBook Air running Sierra

I've a 27" Apple Thunderbolt Display which is connected by the Apple thunderbolt 2 adapter to my MacBook Pro. I'd not been using it much for the last few months so not sure exactly when it started. It was definitely stable back in January. It has started flickering/blacking out for a second or more at a time repeatedly, making it unusable.

It does this on a 2017 and a 2024 MacBook Pro which are both up to date with macOS.

The display has a built-in cable. This appears to be working as I have no problems when it is plugged directly into an old MacBook Air thunderbolt port.

Because of that I assumed it was the adapter and bought a new one (apple's one). But the problem remains.

The MacBook Air it is working on is only updated as far as macOS Sierra. I'm left wondering if a 2024 update to Sonoma 14.5 has broken the Thunderbolt Display since I didn't have problems at the start of the year?

Posted on Jul 11, 2024 6:44 AM

Reply

Answer 1

samtenor

Level 4

1,786 points

Jul 30, 2024 4:18 AM in response to Hooley01

I have many TB displays and there are few things you can take a look..

listen carefully to the left side (when facing the display) - if you hear buzzing sound.

If there is buzzing sound --> power supply is going bad

and

2. after the flicking, go to "About This Mac" -> "More info..." --> "System Report" --> "usb"

If you can not see USB 2.0 HUB --> the logic board is going bad. Usually it happened when I was doing FaceTime and camera/sound would stop working..

These are the two main problems I have encountered with my TB displays (I have more than 6 of them).

Best

Reply

Answer 2

Aug 12, 2024 11:04 AM in response to Hooley01

Recent versions of macOS are supposedly intolerant of transmission errors – as in, they will intentionally shut off a display or reduce the resolution of the signal when they detect such errors.

If the built-in cable is somewhat "flaky", the Macs running old versions of macOS might tolerate the transmission errors, and the display might appear to work on them. The Macs running Sonoma might be cutting the display off from time to time.

You may want to try running a Thunderbolt 1/2 cable from the TB2 side of the adapter to the TB daisy-chaining port on the Thunderbolt Display, thus bypassing the built-in cable.

Reply