external monitor and clamshell mode (problem)

[btownguy]

Hi. I have a MacBook Pro (2017 15") connected to an external monitor via HDMI using the Apple AV dongle (the one that has USB-A, USB-C, and HDMI). On the dongle, I have the standard USB-C charger, the HDMI cable to the monitor, and the USB out from the monitor (keyboard and mouse are connected via USB to the monitor).

It seems to work fine when the computer is awake. If I lock the computer screen and the MacBook Pro goes to sleep (it's already in clamshell mode) I encounter a problem when trying to get it going again. If I try to wake the computer by moving the mouse or hitting a key on the keyboard, the computer appears to awaken but the screen then flickers and won't get the signal. I end up having to open the MacBook Pro and most of the time remove and reinsert the dongle.

Any ideas of what I can do to make it where I can just come back to my desk and move the mouse or hit the spacebar on the keyboard and have the external monitor awaken?

 

[Painter2002]

EDIT: Please disregard my reply... I just realized you said that you have your peripherals attached via USB, not bluetooth.

I am not sure, but have you tried plugging the mice directly into the computer (not the monitor) to see if those will let you wake up the computer from sleep? It could be that the wake from sleep isn't working through the monitor (though I don't see why it should).

 

[btownguy]

Thanks for your reply. The laptop appears to awake from sleep but the video output over the dongle/HDMI appears to be off or not syncing with the monitor. Some combination of the following usually fixes it: open the clamshell, disconnect/reconnect dongle, turn monitor off/on. Pretty annoying and certainly not elegant.

 

[killawat]

Check to see if your monitor has any power save features and, unfortunately, you may have to turn them off to get clamshell mode to play nice. The problem is if your monitor takes too long to wake up then your internal display will turn on and rearrange windows, etc etc. You might also consider swapping out for USB-C to HDMI (or better, Displayport) cables

I use my MBP 98% of the time clamshell mode, not only with a finicky dell monitor but an eGPU as well. Waking up is always a gamble, not as seamless as the old connectivity with the Apple Cinema Displays IMO, but once you keyboard + mouse away from the monitor and get good cables, and check your monitor settings, you should be good to go.

 

[Garage Battle]

Question.

How do you have everything hooked up?

For instance, on the Apple AV dongle, do you have:

Macbook Port 1>AV dongle:

USB-C charger cable
USB-A device
HDMI cable​

OR

Macbook Port 1>AV dongle:

USB-A device
HDMI cable​

Macbook Port2>USB-C charger cable


The first scenario should work correctly. The second one - I can't verify that. I used my 2016 nTB 13" for a year or so with the Apple AV dongle and the Apple VGA dongle and it always woke the monitors from clamshell.

 

[Painter2002]

Actually I just realized that you said you have the wired mouse and keyboard hooked up to the monitor, which is in turned hooked up to the adapter via HDMI, this light have something to do with it.

It could be that since you are using HDMI to feed the monitor it does not keep the connection open during sleep cycles, hence why moving the wired mouse or typing doesn’t wake the computer. I’ll bet there’s a good chance that if you plug the mouse directly into the adapter instead of the monitor, and you test out sleeping and waking up the computer with the mouse it’ll work