LG UltraFine 4K Display issues macbook pro Sleep

I’ve tried in once, and without the power-brick plugged in — only the LG 4K monitor — my 2016 15” tricked-out MacBook Pro awakened properly with the 4K monitor on. Clearly a software issue, and kudos to webdeck for discovering it.

This is actually a good solution until Apple fixes it. The only issue is that when I’m not using the LG and it has been turned off (via a power strip because there’s no power button 😠), I have to remember to plug the power-brick back in.

So it did fix my problems but I was never using the power brick.

Its just failed again after a reboot, but this time both monitors blank.

So, I went into System Preferences, Energy Saver and unchecked Automatic Graphics Switching and both monitors came to life !

I can't believe this: I called Apple Support and mentioned to them that, in addition to this LG display problem, my shiny new MBP with Touch Bar was crashing when using TimeMachine. The (very nice) person at the other end, who obviously had no clue, asked me what I was trying to do with TimeMachine. I then asked for her supervisor, who was not that much wiser and knowledgeable. I mentioned the well known (and apparently widespread) problem that shows up after the LG crash/freeze and after a TimeMachine problem, the dreaded "CATERR detected! No MCA data found."

I have a Macbook 2015 12" and purchased a LG Ultrafine K4 2 days ago. Since that time I've unplugged the power cord from the MacBook 2 times to watch TV in another room. Both times the screen was black when I opened the book and the book was unresponsive to poking. Attempts to restart with the power button failed -- the screen hung half way on the startup white horizontal line. I booted into safe mode, ran disk utility repairs (nothing showed bad), then restarted the machine. One time it restarted normally, one time with video glitches - another restart fixed that one.

All I have plugged into the Ultrafine is the power cord.

I called Apple -- they suggested SMC reboot, which I've done. I'm about 20 feet from the router and have power nap currently off.

I'll update if I figure anything out.

Same problem: Latest Macbook Pro, max configuration of memory and CPU ($4k machine) + The LG 5k display. Random crashes upon plug / unplug, loosing the sound sometimes altogether. It renders the setup completely useless! Apple, we your fix here very soon - those are your top end customers who pay extra $$ for latest and greatest only to find out it prevents them from working...

I have been having these issues consistently until I quit the LG app. I have had no issues what so ever for 3 days now. The only issue is not being able to use the split screen feature\ but I can do with out that.

I have the exact same model as you, I have the LG 5K as well, I did experience a lot of crashes related to sleep and wake from sleep with the MBP with Mac OS X 10.12.2 installed, since installing/updating to 10.12.3 about 3 weeks ago I have had only 1 single crash.

I have to say that I use the touch bar very lightly, most of the time the MBP is in clamshell mode with the 5K monitor connected. My current system uptime since my last reboot (not crash) is almost 9 days. I've never used the LG app, what is the benefit of using it?

I have 2 LG ultrafine 4K screens and I am facing the "one screen is black" issue when I wake up my laptop.

I have to unplug/replug this specific screen in order to get it back. If you do that AFTER waking up the laptop it's very slow (computer undetect/redetect screen so it take a few seconds...).

A workaround (until it's fixed by Apple - still having issue with macOS 10.12.4 (16E195)) is to unplug/replug BEFORE waking up the computer. With this "trick" you "don't have any slowness when waking up the laptop.

I am still having this same issue. Its very strange because it can go as long as a week without happening. I have noticed it is always the same monitor that doesn't wake, even if I switch the cables around. This really is rather enjoying and I wonder how much time I have wanted with this issue. Theater bad point is even if it is hardware related apple is telling me they will not replace the hardware but I will have to send in for prepare. I find this disgusting after spending $3500 on a MBP and close to $1000 on the 4k monitors and they have never worked correctly since I bought it in November.

The only solution I have found (someone else did the finding) is NOT to have two sources of power present when using the LG 4K monitor. If the LG's and the MGP’s power supply are both connected, the monitor will not wake from sleep. If only the LG’s power supply is connected, no problem - well there are other problems, but not this one. So, my guess is that those of us who use two LG 4K monitors simultaneously are currently out of luck, because two power supplies are connected.

I get a kernel panic on my MBP 13" Touch Bar about 10 min after I plug in the LG UltraFine 4K at work. The machine crashes and I need to boot it again. I do not use the power adapter, so it is the only USB-C device connected.

The machine never panics at home (where I never plug it into a monitor).

Very annoying.

This may sounds strange, but I was able to fix this issue by plugging in both monitors AND the power-adapter for a while. After that I could disconnect the power-adapter and both monitors wake up after sleep.

PROBLEM FIXED!!!

LG issued a firmware update yesterday that fixes the problem. However, you must have only one of your monitors plugged in at a time for the firmware update to run. If you have two monitors plugged in, only the LG Screen Manager software is updated, not the firmware. So, update the monitors one at a time, reboot, and no more having to unplug one of the monitors upon restart or after sleep ;-)

Since you just got this, I would contact Apple support, they might give you a better answer:

https://getsupport.apple.com/