Macbook Pro 16" with UltraFine 5K display not waking from sleep

Just an update, that 10.15.14 has resolved the LG5k monitor not waking up or no image problem. Glad to see this resolved for several folks.

Best Regards -B.

I too have this problem with my MacBook Pro 16" and the LG Ultrafine 5K display. The external display would not turn back on after the laptop went to sleep.

I noticed that one user mentioned that manually forcing the laptop to sleep (using the menu option after I woke it) and then waking it again would wake the external monitor. This solution worked for me too. I ended automating the solution by using the app sleepwatcher.

Pretty easy to install and run if you use brew.

brew install sleepwatcher
brew services start sleepwatcher

Edit the file

/user/local/etc/sleepwatcher.rc.sleep

and add the command

pmset sleepnow

I did a reboot and now when my laptop sleeps the app sleepwatcher puts it into a true sleep from which the laptop can be woken with the external monitor turning on.

Ideally Apple will fix this issue, but this is my solution for now.

Can confirm that 10.15.4 has resolved my problem. They have also resolved the issue I had with running HDMI mirroring to my AV receiver (1080i/1080p) where the OS GUI would be locked to half the frame rate - it's all silky smooth now just like my 15" 2019 model was

I am, however, seeing high CPU/high fans whenever I plug an HDMI display in, though. This hasn't been solved.

I can confirm that I don't have any issues with external drives when mbp16 wakes up. The only issues I had was 27MD5KA-B.

27MD5KA-B:

• Wake up = does NOT work
• Auto-Brightness = does NOT work

27MD5KL-B:

• Wake up = works!
• Auto-Brightness = works!

Hi there, I’ve also been following this thread and several others, because I have the issue of my LG 5K monitor not waking up from sleep (connected to my Macbook Pro 16 inch with an AMD 5300 graphics card, which seems less faulty than the 5500–I have none of the other issues you and others are reporting). I have a case number with Apple, and with LG. It looks like this is an issue on the Apple side of things, since it is happening with different brands of monitor, including Apple monitors as you experienced yourself. That being said, I’ve also seen reports of the issue not occurring with the very latest version of the LG Ultrafine 5K monitor. My model number is 27MD5KB-B, manufactured in April 2019, whereas the model now being sold by Apple is 27MD5KL-B. I was interested to see if one of your LGs was this new model number. Here is a link to one thread where “cooperivan” says the issue disappeared when he replaced his B model with the new L model. I’m currently trying to do this with LG as I bought my monitor just over a month ago. I’d be interested to know if others with the new model are having this issue. But chances are that all of us have model numbers 27MD5KA or 27MD5KB.

https://www.reddit.com/r/MacOS/comments/eqyn5t/lg_ultrafine_5k_doesnt_wake_up/

Ok, its been a full day including an evening of sleep and the MacBook woke up today with no crashing. I've spoken with a senior advisor at Apple support and let them know. Hoping this is a good short-medium term fix until they can get Catalina updated with a proper fix.

For the record... turn off PowerNap and the issue of crashing during sleep will resolve. Hope this works for you.

I am experiencing the same problem with my new MBP 16" with AMD Radeon Pro 5500M with 8GB of GDDR6 memory. The Mac will not wake up the LG Ultrafine 5K monitor, when resuming from sleep mode. Does not matter if sleep mode is automatic or manual. After sleep mode, the LG monitor will not wake but Mac still thinks it has two active monitors. My old 15"MBP does not have this problem with this monitor.

Have spent many hours with Apple support and gone through the following 'repairs': SMC, PRAM, Safe Mode, Reinstall OS. Then played musical chairs with all the thunderbolt slots, to check if one of them was not working. Today I went to the Apple Store and had a Genius run all the diagnosis software to check the hardware. All Hardware turns out to be okay. Workarounds are: Restart Computer or pull out cable from monitor to Mac and replug it in. And yes, while testing no external devices plugged in and had the Mac's own power chord charging the Mac, so as not to rely on the LG monitors power supply.

The Apple Genius is pretty confident that the problem is a software glitch that will be fixed in the next OS update.

MacBook replacement did not help... The problem is exactly the same with the new MacBook. This is clearly a software/driver issue. I have tested with two different brand new 16" MacBooks (max everything except storage). I have tested with two different LG 5K displays. I have tested with two HP Z24 4K workstation monitors. Different locations. Different chargers. Different thunderbolt cables... So it's not the MacBook hardware (unless it's all of them). It's not the LG Monitor because I have the problem with 4K HP monitors as well, and it's not power or cables. Also, the 2016 15" MBP I replaced worked flawlessly with all of these monitors... One detail is the problem was worse on the LG monitors than the HP monitors. I can get the HP's to work some of the time. I can't get it to work with the LG's hardly at all. Also, just to make sure the Mac was clean, I tried this as soon as I received the replacement with only having installed MS Office. This pretty much has to be Apple.

I bet the old version has a problem with power delivery and Apple will not fix it because this problem should be solved directly by LG that will not do it 112%. I had a conversation with LG and they mentioned that they don't have any plans to do that... end.

PS I got a new version 27MD5KL-B which works perfectly.

Um no. I do have the sleep wake issue. I had it with my first 16” MBP. Apple support agreed it sounded like hardware so they let me return it and get a new one. I have the same issues with the new one. If you’d have read all the posts on this thread, you’d see that it is not just a sleep/wake issue, but likely a hardware issue that affects everything you plug into any of your thunderbolt ports, displays included. It isn’t only related to the LG5K’s as I have tested both an older and newer LG5K and I have also tested with two HP Z24 4K monitors. All have the same problem, albeit, the LG’s are worse. What I’m pointing out is that the problem isn’t just sleep/wake, and it isn’t just displays. These new 16” MBP’s have a serious driver, firmware, or hardware problem that is affecting IO on the thunderbolt ports. Try plugging in an LG5K (after restart, so it actually works), then try plugging in a couple USB-C external drives to the other side, and watch both your screens flicker and flash on and off and the MBP eventually crash/reboot. I’ve been thoroughly testing and suffering through this issue for almost 2 months now and I’ve tried just about everything. I’m posting everything I learn from tests to try and help others, but if you don’t want it, I’ll stop posting.

I've noticed this with my 2018 Mini. Early days to be convinced this is the cure but I've turned off Power Nap in System Preferences>Energy Saver and so far it wakes within a very few seconds of clicking mouse or tapping space bar.

You could try Cmd-F2 which 'detects displays'. Another way of doing this is in Displays in System Preferences: hold down Alt, and a detect display button should appear in the bottom right of the window.

Haven't tried 10.15.4 yet but wanted to chime in (as a few others already have) that the powering-up issue is happening to my old Apple Thunderbolt display (connected to my Macbook Pro 16, Dec 2019, 2.3Ghz, Radeon 550M 8GB via Apple's own thunderbolt to USB-C adapter).

Reason I wanted to speak up is that, while I don't have a fix, I do have a small tip which makes it slightly less painful (caveat - haven't been able to test if this works on the LG UltraFine - or any 4/5K display). If you wake to a dead screen - switch Mirror Displays (under Displays > Arrangement) ON and then OFF again sorts it out. Pressing Command + Dim Brightness does the same thing (assuming you have the full controls showing on your control strip).

Didn't see it mentioned here, sorry if it's old news.

Success for me so far on 10.15.4. I have one of the original LG 5k ultrafine's, and had the non-wake issue every morning, as well as the max brightness issue. This morning, my display woke up just fine with the correct brightness.

https://forums.macrumors.com/threads/issues-with-peripherals-waking-mbp16-from-sleep-in-clamshell-mode.2220830/ Does what is described in the third paragraph here sound like the issue you had?