Macbook - problems to connect w external screen

I know the update to Sierra doesn't fix it, but I read somewhere that the next update for Sierra might fix it.

I haven't tried restarting the computer without resetting NVRAM. Will have to try that 🙂

Thanks!

UPDATE 4:

I can confirm that the latest public beta 10.12.1 Public Beta 2 does not fix the problem.

Here's where I'm at. Using the HooToo adapter (not apple's) I have much more reliable external monitor.

With the HooToo adapter, I don't get any static as with the apple adapter, but two things persist:

1. When the computer wakes up from a sleep state, I just get a blue screen. Unplugging the HDMI cable and replugging it in, gives me back my image.

2. Every 15-20 minutes I get a black screen on the monitor for about 3-5 seconds, then it comes back on as if nothing happened.

I took my computer, monitor, and cable to the genius bar the other day, they plugged in the apple adapter, and the screen was wigging out with all kinds of interference, so the problem was immediately evident for the mac genius. Again, not what I get with the HooToo.

The genius had never heard of the issue, and thinks it's the I/O cable, so he ordered one (3-4 days) for an install on my machine (another 3-4 days), while not listening to why I'm pretty sure the cable isn't the issue. I hope I'm wrong because I had no other options but to submit. Apparently no one else at this apple store could even field an issue like this, as evidenced by my waiting 45 minutes past my appointment time while 'geniuses' (including the one who ended up helping me) were walking around talking to each other and laughing.

I'll report back in a few days after the new cable is installed.

2016 MacBook m7 on Acer H277HU experience random blackouts as well, leaving me with a 2000$ computer I cannot use for work.

@jtreitz Have you tried restarting your MacBook while connect to the Acer monitor using the USB-C cable provided with the monitor? It seems to fix things for me, at least until I disconnect and reconnect.

yes that works for me too but having to re-open every window and terminal session is such a pain I rather not connect the display at all

I've been having the same issue since purchasing a 2016 Macbook a few weeks ago. When I'm connected to my Viewsonic monitor, the screen goes black for around 5-6 seconds (always seems to be the same amount of time) every half hour or so. It always seems to happen within the first minute of connecting to the monitor, and then intermittently after that. This is with the Apple brand dongle, using HDMI.

Like other commenters here, I've also noticed that the issue doesn't seem to happen if the computer is rebooted with the dongle and monitor connected. This would imply that it's a software issue, and not due to faulty hardware, right?

Yes, it is definitely a pain in the neck. Hope Apple fixes this soon.

RESOLVED (FOR ME)

I got my machine back from the Apple Store with a new I/O cable in it. I made sure to have them test it, and apparently passed tests in their environment. It DID NOT work in my environment with either the Apple adapter or my HooToo.

However, as I was speaking with the store manager I updated to the latest public beta released yesterday (10.12.1 Public Beta Vers. 3), and I no longer have any issues with any of my tests on multiple monitors and cables (didn't work on a monitor that's 10+ years old -- probably just not supported).

My suspicions that this was a power management problem seem to line up with what I'm seeing. Before the newest beta I could set my monitor resolution at 1440 or 4k, and when it worked, gave me a very smooth picture and core animations, etc. (60khz) not what I expected with this computer's documentation.

Now, WITH the beta, 1440 has a much lower framerate/less smooth animations & video, matching what the Apple documentation has always said: for anything above 1080p, you can only expect 30khz (lower framerate) out of these MacBooks. Apparently they hadn't properly told the display management to mitigate the framerate at higher resolutions, but have in the newest beta.

I'm very curious if anyone can update to the newest beta WITHOUT a new I/O cable, to see if it was just an oversight in the operating system.

Thanks all!

Hi , just installed most recent beta without changing cable - I still have a problem with external display detection. Off to buy new cable ....(but not massively hopeful)

Yes, that's my experience too. It was working with Public Beta Vers 3., but the Vers 4 release yesterday broke it again -- now I've got the black screen flashes. too often to do any work on the external monitor.

Also, after the data cable replacement the Apple Store did (that didn't work), I brought my machine home to find the battery was damaged. Two more trips to the Apple Store later, they determined there were a bunch of damaged internals on that machine, so they gave me a replacement machine just yesterday.

Perhaps the tech didn't reassemble the first machine correctly and shorted out power hardware. But I'm wondering if this external display issue and the improper power management by software and/or firmware might have been the culprit for my damaged internals. I sent in a feedback with the Feedback Assistant included with the beta program. It'd be great for any of you beta testers to do the same. Hopefully with the next release of Sierra it will be all ironed out.

UPDATE

After a number of restarts, I now have a reliable, non-flickering external monitor on Sierra Public Beta Vers 4. The only remaining problem for me is when booting or waking the computer I get a blue screen until I unplug the HDMI cable from the adapter and plug it back in.

I have the same flickering problems with my spring 2016 Macbook 12" 1,3 GHz Retina on an external Apple cinema display (the old version with the non-glossy screen). I use only Apple OEM adaptors/connectors. Every morning when I arrive at my desk and hook up the monitor the external screen keeps turning black for a split second, sometimes 3 or 4 times a minute, or turns black and stays like that and the indicator on the cinema display blinks three times. Then unplugging the connector helps until it starts all over again.

I found that a restart helps, and I have no flickering throughout the day until the next morning. Only exception: when the machine falls into deep sleep when the battery is completely empty. Then the problem reoccurs, here again a restart helps.

Apple helpline and genius bar couldn't help, they gave me the impression I am the only one with this problem and advised me to watch, check the cinema display with a different machine (worked fine with my old Macbook Pro), and check it with a different Macbook 12 Retina (haven't found one yet). But this thread shows me I'm not alone.

Do we already have hints wether this is a software problem (with the hope it will be fixed one day) or a hardware problem? Does Sierra 10.12 from September 20 help?

Still broken in 10.12.1 (public released version). Good news, though! Apple is about to ship brand new USB-C MacBooks, so this problem could be widespread on every Mac platform soon and maybe we'll get some attention towards a fix.

Just to add to the growing list here...I'm having the same issues as all of you. (Apple, are you listening?) Brand new Macbook 12 Retina Display, LG monitor, Apple brand dongle, monitor cuts in and out often. Usually for about 2-3 seconds and "HDMI" shows up in the top right of the monitor and then back to normal...for a little while. And then the process starts all over again.

I've updated to Sierra 10.12.1. I've also reset the SMC and NVRAM. Whatever the heck those are. And same issue...over and over. Very frustrating and really makes this computer not usable for professional use (e.g. presentations to clients).

If anyone has found the magic fix, please let me know! At this point, I'm starting to pick up my 9 year old Macbook more often. Lame!

Thanks,

Reid

This:

http://appleinsider.com/articles/16/10/20/owners-of-apples-2016-12-inch-macbook- report-usb-c-to-hdmi-adapter-flickering