with 10.11.2, Mac Pro 2013 will not wake up 4k displays after sleep like before.

I have the same problem with a Mac Pro 2013 and a Samsung U32D970 4k monitor after updating to OS X 10.11.2. I do not have any of the input devices mentioned by Ruoyu. However, I found that the monitor does correctly turn on when waking the system up by pressing the main power button of the Mac Pro. I have reproduced this three times.

Hello.

For me, unfortunately, helps none of your tips.

same issue here, bug report 23840183

One thing which wakes the display up, I have found with my Mac Mini, is doing screen sharing from another computer into that computer.

Obviously this *****, but it might ... be better than nothing until Apple fixes this nasty one.

Done. And I have referenced this discussion as well.

Unfortunately, that doesn't work for me 😟

Ruoyu wrote:

I have installed 10.11.2 today and found the Mac Pro will not wake up the 4k displays connected to thunderbolt ports. I tried many kinds of 4k displays including u28e590d, u24e590d, p2716q etc, but none of them would wake up after sleep. the only resolution is to unplug and replug the thunderbolt (display port) cable to a different thunderbolt port.

those displays all work perfectly with 10.11 and 10.11.1.

Steps to Reproduce:

1: have a Mac Pro 2013, any configurations and install 10.11.2

2: plug a 4k display like u28e590d to thunderbolt port using mini-displayport cable.

3: let the Mac Pro go sleep

4: when press a key or click the mouse, the Mac Pro will wake up but the 4k display will not wake up.

anyone is experiencing the same problem?

have you checked the logs for any error messages

Another option is to run http://www.etresoft.com/etrecheck

looking for error messages to see if for some strange reason the driver for your display was killed by memory management.

Same problem with a MacPro2013 and Samsung U32D970Q when updating to 10.11.2. Samsung tech support says it's a problem with the Apple update. I spent some time at the Apple store yesterday and confirmed the monitor works fine on machines that have not been updated.

I have some logs here:

Details Here

Same problem with Asus PB287Q.

I have had varying degrees of success with moving the DP plug on the Mac side, but it is really frustrating. I have disabled the energy saving options until it gets fixed.