Macbook 2016 HDMI output flickering

Beta 4 available.

Beta 3 has been more or less stable in terms of flicker. Hopping this one is even better.

Switched to Beta 4 today. Just disconnected my HDMI monitor and then the internal display started blinking like mad, had to reboot to get out of that state. Didn't see this with Beta 3.

Thanks for the update tom-ch. Based on your feedback I'm going to pass over Beta 4 for now. I'm really happy with the stability with Beta 3 and don't want to jeopardise it. Perhaps next week when I don't need an external monitor as bad!

Didn't see any flickering of the external (HDMI) monitor with Beta 4 so far, it was just the weird behaviour of the internal display after unplugging the HDMI adapter. Anyhow, needs some more testing time...

Haven't seen the flashing on internal or external display on Beta 4. Currently testing it on 4 identical 2016 MacBooks.

No flicker or blink on beta 4 so far.

However, on one external projector today I got the weirdness again after reseting the resolution. This time it didn't went away after a few seconds, I had to reboot.

On other two external monitors no issues so far.

Ok, i ran into this issue as well yesterday. I thought it was a defective monitor at first.

I have a Dell U3415W. I tried rebooting at first and it didn't help. I found out when i went into the system preferences > displays > color that it was set on a generic monitor profile. I changed it to U3415W and now i don't have any issues.

Don't know if this actually solves the problem for good? I'll have to test it a few days longer. Can someone else with this problem check to see if this is the fix?

I second this. I have two 2415 Dell's. Moving on to the beta's resolved the black screen flickering.

Yes, I can confirm that.

Yesterday weirdness started exactly on mirror mode. However switching back to extended mode didn't solved it. Only a reboot.

In my humble opinion, USB-C display is much more sensitive to small cable and display standard deviations than DisplayPort did.

but there's something about Sierra that is not working as it should. Some users report fans kicking on previous retina generation machines.

I found out that if you switch your audio to another device like for example the internal speakers that flickering does no longer appear. This works with internal speakers and also with my USB-C dock.

So just connect the screen using the HDMI - USB-C adapter, click on the Volume icon and hold the ctrl key and then switch to internal speakers or any other device.

Let me know if it works for you as well...

For users of the LG 27UD88 monitor connecting over USB-C, I have installed beta 4 and can report the following:

1. Straight after installing the beta I experienced a lot of visual glitches and artefacts on the LG monitor, which seemed to be caused by moving windows around the screen. Some artefacts were static (like black lines or patches of pixels) but others were flashing and strobing, which was very distracting
2. After a few minutes of this I decided to open System Preferences and see if changing resolution improved things. As soon as I selected a new resolution both screens went black, there was a kernel panic, and I saw the black "Your computer restarted because of a problem" screen
3. Since this episode (approx 36 hours ago) everything has been working well, and the LG monitor seems to display an image much more quickly after connecting the USB-C cable
4. When I came into my office this morning and pressed a key on my MacBook the LG monitor immediately beeped and turned on. Previously I would get a black/unresponsive monitor each morning and would need to restart the MacBook and disconnect/reconnect the power supply of the monitor before I could start work.

I have sent the crash report for the kernel panic to Apple via Feedback Assistant, so hopefully they are aware of it.

Fingers crossed the stable performance continues under this beta and this issue may be resolved once and for all!

I've been following this thread for a while, as I've had the same issue since I purchased a 2016 MacBook in October. I've seen flickering (each dropout lasting about four seconds) with two different external displays, connected via HDMI and the Apple multi-port adapter. The problem seemed to disappear every time the machine was restarted, but the flickering began anew after a couple days' normal use. An Apple representative had me reset the NVRAM, which did work temporarily, likely only because the process involved a reboot. Not only did the issue cause external displays to flicker while in use, but when the computer was asleep, the monitors would turn on intermittently. This, too, was very annoying.

This was not the only problem: I noticed on my first day with the machine that my bluetooth mouse was responding slowly and erratically when my computer was connected to my home wifi network. I worked around this issue by replacing my wifi router with a dual-band router, and by connecting my computer to the 5 GHz band. I do wonder if interference is the root of all of these problems.

Regardless, updating Sierra to the third beta release, and then to the fourth, seems to have almost completely resolved the monitor issue. There is still a little bit of weirdness, with the external monitor turning on without any discernible reason while the computer is asleep, so using an external monitor with the 2016 MacBook is not quite the same as it was with my 2010 MacBook Pro...but at least we know they're working on it, and I'm no longer inclined to trade my new machine for a 2015 Air.

I can confirm as well that installing the beta 4 helps and cures the problem for me.