External Monitor/TV Disconnection in Clamshell (reappears when moving mouse then turns off)

Question

Level 1

4 points

External Monitor/TV Disconnection in Clamshell (reappears when moving mouse then turns off)

So I am using the USB-C AV adapter to connect my 22 MBP 13" M2 8GB. When I have the adapter connected and the TV set to Main Display (I can see, do, work, move...) and MBP to extended display when I close the clamshell the TV starts acting like it is trying to get an HDMI signal then it says "No Signal". Now I would assume hey I somehow turned off the setting to allow the device to stay awake when the clamshell is closed.

WRONG!!!!

Prevent automatic sleeping on power adapter when the display is off. Its already on!

Now here is the kicker if I touch one of the keys on my keyboard or keep running my mouse around the screen the HDMI picks up displays for 3 seconds then it processes the signal again and then "No Signal"

I can repeat that process from now till the next millennia but ultimately nothing can be done like that. So I open the clamshell back up to check settings the monitor/tv picks up the signal like it is nothing again. So it can't be the cable, it can't be the adapter (apple branded), it has to be a setting somewhere or an issue somewhere that is causing this. Any help would be greatly appreciated.

P.S. I have plugged, unplugged, restarted, turned on tv, turned off tv, I have googled, I have even asked my cat if she has any idea and she fell asleep because she was so exhausted trying to come up with a solution.

Also this started happening in the last 3-4 days, I cannot remember if I ever connected it to the TV when I got home from class the other day or if I just used the built in display because I was just reading a few pieces of data off my screen but I do know it was working over the weekend in clamshell mode.

MacOS Sonoma 14.0 (23A344)

Samsung QBQ90S 55"

USB-C Digital AV Multiport Adapter-MUF82AM/A

If you keep seeing this edited then I am adding potentially relevant info as I think about it.

URU7100

Posted on Oct 25, 2023 12:13 PM

Reply

Answer 1

Top-ranking reply

ParkerBeach Author

Level 1

4 points

Oct 27, 2023 4:52 AM in response to ryane77

Good Morning Ryane77,

So as per usual when having an issue you just keep messing with things until you figure out the issue. After writing my message the other day I starting thinking a little deeper wondering if something had changed in the softwares. What I found was that either apple changed a setting when I switched to Sonoma or something had been reset on my TV.

Turns out that despite never having had to set it previously something was not communicating between the TV and my Macbook and when my laptop was going to sleep it was messing with the refresh rate on the TV.

I do not recall the setting but it had to do with turning off the smart setting for that port. I had seen people mention refresh rate on other posts but having never had the issue for almost a year on this TV I didn't think that the setting applied to me.

I will keep an eye on this post to see if anyone else has this issue over the next week or so in case they need step by step walkthrough in which I can turn on my TV an go through the settings and type out a walkthrough.

I appreciate the time you took to reply. I will mark it helpful as I am sure it could be of use to others but this seems to be a very specific issue.

Have a wonderful day!

Now as for answering your questions:

I had used a different HDMI cable in the past but this cable had been used previously on this setup with no problems. I do not have any other HDMI adapters for my MBP so I had no other way to test additional adapters.

Reply

Answer 2

ryane77

Community Specialist

Oct 26, 2023 11:05 AM in response to ParkerBeach

Hi ParkerBeach,

We'd like to see if we can help out. To clarify one point, we see you mentioned you're using an Apple-branded adapter and cable combination. To rule out possible issues, have you tested other cables/adapters? That would be good information in narrowing things down.

You could also set up a temporary administrator account and test there to see if you can replicate the issue. This will tell you if it's system-wide or user-specific. New user or group setup on Mac - Apple Support

Once you test in the new user, let us know the results.

Also, if you haven't yet, make sure you've worked through all of the steps in this link as they could help: If your Mac doesn’t recognize an external display - Apple Support

Take care.

Reply

External Monitor/TV Disconnection in Clamshell (reappears when moving mouse then turns off)

Similar questions