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

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.

Our setups are very similar - only difference is that I have the 8GB graphic card, see my setup below:

Purchased in December... 16" MacBook Pro

• 2.3GHz 8‑core 9th‑generation Intel Core i9 processor, Turbo Boost up to 4.8GHz
• AMD Radeon Pro 5500M with 8GB of GDDR6 memory

I ran a 2017 15 inch MBP with the LG Ultra fine 5K display without any problems.

Besides the cannot wake from sleep problem the 16 inch also has problems with scrolling menus. They tend to blank out while scrolling.

So far - no solutions but I think Apple should stop advertising that this computer is built to run multi 5K monitors!

Checking in with my specs. I'm experiencing the same waking problem and 100% brightness with my 16" MBP and LG Ultrafine 5k.

Specs are maxed out. Not sure if anyone else has the same on here, but I'm leaning towards this being a software issue.

• 2.4 GHz 8-Core Intel Core i9
• 64 GB 2667 MHz DDR4
• AMD Radeon Pro 5500M 8 GB
• Intel UHD Graphics 630 1536 MB

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!

I'm of course here with exactly the same problem. There was some suggestion in the thread that it's an MBPr issue, or the UltraFine 5k being the issue, but I think it's a combination of the two that is the problem, perhaps video card specific but who knows. I just know that Catalina has been a complete garbage release from a quality perspective; just one thing after another. Here's my setup:

• 2019 iMac (non-Pro) 27 with retina 5k and Radeon Pro 580X 8GB card with this exact same UltraFine 5k monitor (27MD5KLB) - zero issues at all with the monitor waking from screen power off (I never sleep that computer). I tested letting it sleep though, not deliberately putting it to sleep, and the monitor woke up fine.
• My MBPr 16 has the Radeon Pro 5500M 4 GB setup, and at a different location I have two LG UltraFine 4k's (model 24MD4KL). Those displays never have this issue.
• I just received an additional UltraFine 5k yesterday to use with my laptop at a different location, and have been running into this problem more often than not when the screens are supposed to wake. The laptop is remaining on and open, I just have the displays turn off after five minutes.

So, same monitor, non-laptop Apple computer, same OS; no issues. MBPr 16, same brand of monitor; no issues. MBPr 16 and the 5k, issues.

Pretty frustrating, as is the case with most Catalina BS that never seemed to occur in previous releases.

Please forgive my ignorance mick80234, but I'm not sure I've followed your instructions correctly, as my Macbook is not going into a true sleep when my LG 5K sleeps following my edits to the file. Here is what the file now looks like (might you be able to confirm if I've inserted the command "pmset sleep now" correctly?):

Thanks!

Thanks for placing your solution. I forgot to mention it. Yes, sometimes it does work to just select sleep and then waking up the Mac. For me it is sporadic (out of 5 tests it worked twice) but I would highly recommend trying it, as it is a lot easier than pulling out cables.

Having the same issues as well. Fresh install, reset SMC, zap PRAM, all with no change in symptoms. If I manually put it to sleep it will wake up *almost* all the time. If I let is sleep on it's own it's always a black screen on the LG.

Also I use the MacBook closed when attached to the display with a Magic Keyboard and Magic Mouse. Lights (like caps lock) work indicating the laptop did wake up. Also if I open the Macbook the screen immediately works while the display is still black.

Oh how I wish Apple didn't get out of the consumer display business. This LG Ultrafine 5k has been junk and bug ridden since I got it years ago.

You are pointing the problem to the LG Ultrafine 5k as being problem and you may be correct. Maybe the firmware for the LG monitor needs to be updated? In doing my tests I find that when I link the 15 inch to the LG monitor, everything works perfectly, I am only experiencing these issues when I connect the 16 inch to the LG that I am experiencing the following problems:

1) LG monitor will not wake up after sleep

2) LG monitor turns on at 100% brightness

3) 16 inch will not shut down if connected to LG Monitor, it hangs in black space where you only can see the arrow and then you have to do a force shutdown.

I did download the LG Monitor app from the App Store and ran the firmware test on the LG monitor. When I get home tonight I will look to see what they say the latest firmware version is. My monitor is apparently up to date.

This is interesting Nick. I just updated my MBP 15 to Catalina to test the LG this weekend. I will run more tests this evening to see if I can replicate the issue. I don't know how to escalate an issue except that when I recall Apple Support, I give them the original case number to look at. Then the support staff contact engineers to see if they can get a solution. I assume this is recorded? Also when I went to the Apple Store, all the notes from phone calls were recorded and the genius was referring to them. I also suspect Apple Bots are trawling these pages. As Apple sells the 16 inch as a power graphic machine that can run multi monitors I suspect they would want to fix the issue?

So far in this discussion we are pointing at one of three things that could contribute to the problem.

1) Catalina

2) Graphic card driver

3) LG monitor firmware

If anyone can think of anything else, please continue to the list.

Having the same issue with an external display (LG UltraFine 5K Display) where sometimes the MacBook Pro doesn't recognize that it has the display connected to it. This is usually when it wakes from an extended sleep. I have to restart the MacBook Pro, disconnecting and reconnecting the cable doesn't seem to help. It is connected via the Thunderbolt 3 cable that came with the display (uses one cable to charge and feed video). I have the display set as my primary display with menu and the MacBook Pro is the secondary display. Prior to this display I had the original Apple Thunderbolt Display that I connected with an adapter. Same thing was happening, so I thought it was the display and adapter, which is why I purchased the new display. I have swapped the supplied LG Thunderbolt 3 cable with the Apple Thunderbolt 3 cable. Same thing happens.

Hi Tom,

Which MacBook Pro and graphic card are you using?

Thanks for mentioning that you tried changing the Thunderbolt 3 cable, which did not solve the problem, you have just saved money for a lot of folks out there.

*may be able to rule out Catalina*

I just did a TimeMachine restore of my 2018 15" Macbook pro (already running Catalina 10.15.2) to the new 2019 16" Macbook Pro. The 15" had zero issues waking back up the monitor from sleep. The 16" has this issues immediately after restore (as it did from a fresh Catalina 10.15.2 install)

I've got the Radeon Pro 5500M 8GB version

Full specs:

64GB RAm

2.4GHz 8-Core i9

2TB SSD

5500M (8GB)