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

Ah, I see. Don't worry about it, because if you don't have the box, then the number would only be visible if you remove the mounting cover on the back of the monitor. I was only asking because if your model were an older A or B one, then your experience might give those of us with the same models a ray of hope. And if it were the latest L model, then it would help confirm that the issue is not happening on these newer models that are the only ones (I think) Apple is now selling. But it's academic anyway, as the underlying cause of the issues most of us with LG and other brands of monitors are experiencing has to do with Apple/Catalina, and it is that cause which must be addressed by Apple. I was just clutching at straws...

all of a sudden, yesterday morning my LG ultrafine 4k monitor wakes up when my MBP 16" wakes up. its a miracle! I installed 10.15.4 a week or two ago and it didn't seem to do anything. I installed the update that came out I think last week ... didn't do anything. Now ... it works!

also, ive never had the super brightness problem or anything like that. Just the "won't wake up" problem.

I have had no issues at all ever since the first update that fixed this issue. No problems after the latest update either. And I'm wondering why. Maybe it is linked to the type of graphics card? I opted for the simpler one at purchase: AMD Radeon Pro 5300M 4 GB. In the past on this thread, it seemed like people with the more advanced one (AMD 5500) had more and stranger problems than I did. Just a thought.

I'm running 64gig MBPr 16, connected to LG 5k via their included cable right now. Laptop is open so both screens are on, high brightness, external keyboard and mouse connected to monitor, also running vmware fusion with a fair load. I've only had the monitor for a few days but it hasn't had any issues supplying enough power. I do have a 4k 24" LG monitor at a different location and its power supply isn't sufficient for the 16; the battery will slowly drain over the course of the day if I don't get the brick out.

I'm on Catalina 10.15.5 with my 15" MBP (2017) and the 5k display is consistently blacked out or it will intermittently display but lock up the laptop. When I connect the display to my Alienware R3, it seems a lot better, but frequently flickers in & out. I'm also using the black cable that was provided from LG.

(still scratches head)

16" MBP on 10.15.4 --- original LG Ultrafine 4k still doesnt wake unfortunately. Had to do the unplug and plug dance.

16: MBP on 10.15.4. Still no go on both my LG 5K monitors. One purchased 2 years ago, the other on purchased last September.

These monitors work fine with my Mac Pro.

K-NJ. That’s what happened to me as well. The patch created problems and now after a couple of unrelated reboots everything seems to be working

The last update fixed it most of the time but not all. It's a lot more rare now, perhaps once in every 10-20 times as opposed to consistently. Glad it's not just in my head!

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.

I had the same sleep/wake issues with my 10+ year old Apple Thunderbolt Display and the 16" MBP... I figured it was the Apple display and adapter which is why I purchased the LG (I also liked the higher resolution of the LG).

Incidentally, I'm running into issues running audio to my A/V home theatre processor that causes my UI to lag and lots of CPU to be used, although oddly enough nothing shows in activity monitor to indicate what may be causing the heat/power drain etc. Happens in both mirrored or spanned mode, but I usually mirror via HDMI to get audio (since there's no way to get audio-only out of HDMI in a Mac, which is frustrating). Been doing it this way since 2016, but only hit that issue on the 16". Perhaps it's a similar issue relating to drivers somewhere.

I sure do miss listening to music...

We are talking about a sleep/wake issue here; the issue you described sounds quite different. Your posts have made this discussion rather confusing: at first I thought you confirmed that a replacement 16" MBP would not solve this issue, but after reading through your comments I saw that you weren't even talking about the sleep/wake issue.

I'm sorry you're having the problem you're having, and I'm aware that there probably aren't many threads out there that touch upon anything closely related to it, but please don't muddy the waters --- have more consideration for others. You want to talk about your problem? Fine. But make it clear that that is what you're talking about, and not the sleep/wake issue that is literally the topic of this thread as stated in its title.

The evidence for your hypothesis that this this external display sleep/wake issue is just a special case of a more general issue is pretty weak. Can you produce a convincing argument for this? Problems aren't necessarily related to one another (obviously).

You didn't mention anything about the sleep/wake issue before you declared that "the problem [whatever that is] is exactly the same with the new MacBook." You were talking about screen flickering, which is not the same thing as the sleep/wake issue that is being discusses here. It is very unclear what you are talking about at this point. Are you saying your HP monitors have the same sleep/wake issue? Are you saying that you tried it with a new 27MD5KL-B, not just a newer 27MD5KA, and that the sleep/wake issue persisted? Another commenter (ivancucer) said that their 27MD5KL-B, which is designed to work with the 16" MBP, works “perfectly”.

I don't have external drives at hand with which I can do what you asked me to do. Needless to say, this may have nothing whatever to do with the sleep/wake issue.

I don't know why you think it's okay to insult and mock me. I think it was reasonable of me to be slightly miffed about the fact you were sowing confusion. When you first mentioned the flickering, you didn't say it happened because you plugged in an external USB drive. I have also noticed that it seems to be the case that it's more likely that the sleep/wake issue will present itself after the MPB has been doing something at least moderately intense, although I am not sure. This suggests that it may in fact have something to do with the power.

Then again, maybe not; see this Reddit thread on this same issue: https://www.reddit.com/r/MacOS/comments/eqyn5t/lg_ultrafine_5k_doesnt_wake_up/ A couple of presumably non-16" MBP users said they had this issue, and that a software update fixed it. This gives me hope. I suppose a software update is our only hope, unless someone very determined creates something all on their own independently of Apple and LG. It's something I wish I could do myself, but I don't know how these things work.