10.12.4 display sleep bug

I have this same bug with dell 4k monitor and LG 39'' monitor! and even with HP 24'' but on my MacBook Pro 2016 ( with touch bar ).

And I have very strange behavior with desktops while using external monitor:

When I run some program on fullscreen (let's say on my MacBook's monitor) then my external monitor become black. When trying to move desktop (by touch pad) it's moves on both monitors.

P.S. yea, I am always here to help apple if they need me

I've found a cure, for me at least.

I've been experiencing this issue since installing MacOs10.12.4 as noted in an earlier post under this topic.

I removed all apps that loaded on startup that also directly affected the display including the Caffeine.app. I did this under System Preferences > Users & Groups > Login Items. Then, I shut down my iMac completely, and let it sit for a few seconds. Then I turned it back on. (Restart may have been enough. I don't know.) I tested it over the course of the day after it slept for at least an hour and overnight. This fixed the problem.

Just to be sure that was what was causing it, I reinstalled Caffeine and set it to load at startup and restarted the Mac. The problem returned. Removed it and deleted it from my hard drive. The issue is gone and everything is working fine.

Some time back, I noticed that the caffeine.app had been removed from the app store. I wonder if this was why. Too bad. This was a great little app until it caused this issue.

Note: I can't edit my previous post, so I'm amending my post.

Problem continues. Occasionally, both external monitors won't display anything in the same manner as the iMac, but the iMac continues to run. Rebooting is still the only fix for getting all displays working at once.

I'm not running caffeine or any other display/sleep altering applications (that I know of).

This is happening with my new MacBook just received 2 weeks back. I've upgraded it to 10.12.4 and I don't even connect external monitors. Have submitted the diagnosis logs to apple support. Only solution is. reboot once it enters this black screen mode. Really nasty bug as I need to reboot every day.

I also have the same issue however mine is a late 2012 iMac without any external screen. I am however using an external SSD drive. The problem started after one of the recent Sierra updates. I had no problems before the update with the same configuration.

I'm so frustrated with the issue that I'm considering switching to the new Microsoft Surface desktop but am hoping Apple issues a fix soon.

Same issue again, MacBook Pro Early 2015 even without any attached monitor. About half the time, opening the lid won't turn on the display. Usually to close the lid and retry a few times, and more than once a reboot has been needed. Again it seems a new issue (or very much worse) since 10.12.4, but I wouldn't assume the type of monitor is a huge factor. My other Mac, a Mini with two displays attached, is very noticeably much more sluggish at starting the HDMI display compared to the mini port one. Feels like a timing issue to me, but I am glad Apple's on the case. This is frustrating to say the least.

I have just installed 10.12.5 beta (16F71b) and so far it seems to have fixed the problem ... will report back if the home set-up is not fixed by the beta or if the problem recurs. (2x identical setups (5k i7 iMac + Dell P2715Q))

I updated to 10.12.5 Beta (16F71b) as well, but the issue remains for me. The iMac display and external monitors appear to try to wake up on key press, but all immediately turn off after. Continuing to press keys and so forth sounds like the OS is still functioning. I really hope this is addressed on 10.12.5 as this absolutely annoying.

Sorry to say even with the beta update to 10.12.5 (16F71b) the problem is still present but intermittently on at least one of my two set-ups (they should be identical!?).

Really annoyed! If it is not fixed in 10.12.5 then I am considering returning my computers.

10.12.5 (16F71b) is beta 5, so that's the most current version not fixing the problem. Disappointing.

10.12.4 introduced Night Shift, the mechanism for increasing the warmth of the screen in late hours. Given that this is a display subsystem change, it's possible the new display bug is related. Is there any chance that we all have that enabled? I've disabled it on mine and will see if the black screen problem returns. It's in the display system preferences in its own tab.

Adding another data point: I just got my own iMac 2014 Retina back from repair for an unrelated overheating issue. I believe the logic board was swapped out because the MAC address has changed. This problem persists with that brand new part. Previously I verified that this issue persisted with a fresh OS X install. An external 4k display and USB and Thunderbolt storage devices were the only non-standard additions.

For those joining the thread late: Earlier in the thread, somebody mentioned that they were having luck as long as they remember to power off their external Dell display before letting the iMac go to sleep. A few others reported success, with one other still having the problem.

You might also take a moment to get a VNC app for your iPhone or iPad. RealVNC is one that's free. I see a good many other choices. Enable desktop sharing on your Mac and get that working now. Then you can at least log in with your phone and see your desktop when the display won't wake. I do this so I can cleanly exit programs and shut down. Basically I'm using my iPhone as an additional mirroring monitor temporarily. It's laggy as all get out, but it's better than hard power offs.

Well, I had this problem when I updated to 10.12.4 on 03/29 and I just did the 10.12.5 update and the problem is still there. A little recap of the original:

"when I come out of power saver (display off but computer running) the iMac screen stays dark. Well, almost. The screen comes on for a split second and then stays off. I have 2 4K monitors hooked up and they both come on like normal. "

I had been contacted by an AppeCare customer rep (Todd Seydel) who had me send in some files to the engineers at Apple to help them duplicate the problem. I had high hopes but to no avail. The problem still exists, and it in fact worse now than before. Instead of just the iMac monitor staying off and the 2 external monitors coming on only 1 monitor comes out of power save and the others stay off. Just thought I'd get this posted right away to let Apple know it's still not fixed. Hopefully this will be remedied with 10.13?

I also had this issue when updating from 10.12.4 on my 5k iMac. I updated yesterday to the official release of 10.12.5 and the problem still persists. I currently have a 28" Samsung 4k monitor that always turns on, but another LG 27" 4k will only turn on sometimes when waking monitors from sleep. When the LG doesn't turn on, the primary display on the iMac lowers it's resolution and switches sides with the Samsung monitor. The only solution I have found so far is to unplug the display port cable on the LG monitor and then plugging it back in to get it to work again. Occasionally the problem presents itself differently and both the Samsung and the LG monitors turn on at full resolution, but the iMac screen stays black and the only way to solve this is to restart the iMac.

Never had any issues previous to 10.12.4 related to the monitors not turning on after sleep or functioning properly. This has been a serious frustration ever since. It happens about every 5-10 times I put my screens to sleep, and I have to do that regularly with my job.

We need to open a new Thread as this has become a 10.12.5 bug and in my case is now more serious.

I had just updated to 10.12.5 16F73 and with 24 hours my system froze when I tried to wake it up while it was in screensaver mode.

The screensaver images froze on the two external monitors while the iMac monitor went black.

The system was unresponsive and I had to power cycle it.

I am looking forward to discussing this problem with Apple engineers at WWDC in a couple of weeks.

Also plan to put in another call to Apple support on this.

iMac (Retina 5K, 27-inch, Late 2015) + Acer B326HUL DisplayPort + Acer K272HUL DisplayPort

Cheers, Joe

Unfortunately this does affect Mac Minis. I have a Late 2012 2.6ghz Mini with 16gb ram attached to 2 Dell 24" displays - U2410 & U2413. I've literally done a bare bones reinstall of Sierra this morning and still get the black screen of death. This first started for me on 10.12.3 and still persists in 10.12.5

Things I've personally observed:

1. Mini boots to the U2410 (HDMI) but switches to U2413 (Thunderbolt to DisplayPort) in OS start up - this has always been the case regardless of version of Mac OS, but worth mentioning

2. Regardless of whatever else is plugged in to the other ports (USB, FW) after sleep for a prolonged period of time the U2413 display won't wake.

3. It seems to be a combination (in my case of which is the HDMI display - mine is U2410) if I swap the cables around U2413 works as expected

4. While disabling energy saving fixes the issue (as the displays never turn off) this is not a solution temporary or otherwise :(

5. Turning off the monitor and putting it to sleep does fix the issue (sometimes and only temporarily)

6. NVRAM & SMC resets appear to have no effect

7. My mini also does the primary display "flash" before falling in to a coma never to return

On a side not I have noticed that the primary display displays services starting up before the OS has fully booted (Dropbox etc) - so I can see the desktop briefly as a flash then it disappears again, while the actual log in sequence finalises.