Mac mini 2014 won't wake monitor via HDMI

Hi all,

Can't believe how long this thread has been going without any real solution. In my setup, I have a 2012 Mac Mini i7 connected to two monitors. The HDMI exhibits the same problems everyone has in this forum but the other monitor connected via Displayport wakes up everytime. So it has to be the HDMI issue.

I've also noticed that I can wake the HDMI monitor up ONLY if I wait for the Mac to truly fall asleep. Many times the Mac is sleeping but the white light on my Mac Mini stays solid white. I always need to check if the Mac is truly sleeping by monitoring this light. Here are the steps:

1. Check if white light is solid.
2. Wake up Mac by pressing anything.
3. Put Mac to sleep. (I use Alfred to force sleep. Other users can try a Sleep shortcut key combination. Think it's CMD+Opt+Delete)
4. Mac should have slow, pulsing, white light.
5. Tap any key and the HDMI monitor will wake up.

I've tried to determine what processes are preventing my Mac from fully sleeping but it's hard to understand as I'm not a computer engineer.

When I run this in terminal:

pmset -g assertions

Assertion status system-wide:
   BackgroundTask                 0
   ApplePushServiceTask           0
   UserIsActive                   1
   PreventUserIdleDisplaySleep    0
   PreventSystemSleep             0
   ExternalMedia                  0
   InternalPreventDisplaySleep    1
   PreventUserIdleSystemSleep     1
   NetworkClientActive            0
Listed by owning process:
   pid 67(powerd): [0x0002a3700010815d] 00:04:29 InternalPreventDisplaySleep named: "com.apple.powermanagement.delayDisplayOff" 
  Timeout will fire in 131 secs Action=TimeoutActionTurnOff
   pid 130(hidd): [0x00029fe90009a240] 00:19:32 UserIsActive named: "com.apple.iohideventsystem.queue.tickle.4294969003.3" 
  Timeout will fire in 1200 secs Action=TimeoutActionRelease
   pid 5084(Google Chrome): [0x0002a3950001a27a] 00:03:52 NoIdleSleepAssertion named: "Uploading data to gfpu.line.naver.jp" 
   pid 256(nfsd): [0x0000000600018049] 48:06:28 PreventUserIdleSystemSleep named: "com.apple.nfsd" 
Kernel Assertions: 0x4=USB
   id=504  level=255 0x4=USB mod=1969-12-31, 7:00 PM description=com.apple.usb.externaldevice.14600000 owner=IOUSBHostDevice
   id=506  level=255 0x4=USB mod=1969-12-31, 7:00 PM description=com.apple.usb.externaldevice.14200000 owner=IOUSBHostDevice
   id=508  level=255 0x4=USB mod=1969-12-31, 7:00 PM description=com.apple.usb.externaldevice.14500000 owner=USB3.0 Hub             
   id=511  level=255 0x4=USB mod=1969-12-31, 7:00 PM description=com.apple.usb.externaldevice.14100000 owner=USB2.0 Hub             
   id=515  level=255 0x4=USB mod=1969-12-31, 7:00 PM description=com.apple.usb.externaldevice.14140000 owner=USB2.0 Hub             
   id=517  level=255 0x4=USB mod=1969-12-31, 7:00 PM description=com.apple.usb.externaldevice.14540000 owner=USB3.0 Hub             
   id=518  level=255 0x4=USB mod=1969-12-31, 7:00 PM description=com.apple.usb.externaldevice.14143000 owner=USB Receiver
Idle sleep preventers: IODisplayWrangler

It's always the IODisplayWrangler in the end but I'm not sure what to do next. It's not a complete solution. I think if we determine what process is keeping the Mac awake we can make sure that it turns off the display properly.

I thought all HDMI cables were the same. Apparently not. My Mac mini connects to a Dell monitor using the HDMI out and at the monitor a HDMI to DVI adaptor. The cable is short but very thick. The MAcmini has been successfully putting the monitor to sleep and awaking it for months. One day, I needed to use a longer cable so I borrowed one from a spare on the TV. This was one of the really cheap ones I bought on Ebay and the cable is noticeably thinner than what I was using. When the Mac went to sleep the monitor went black. When I woke up the Mac (usually from hibernation) I noticed that I had to turn off the monitor & turn it on again before the screen would display. Today I replaced the HDMI cable to the previous short fat one and it is working OK. One forum site (forgot it) had a link to "How Stuff Works" where differences are explained. http://electronics.howstuffworks.com/hdmi2.htm

Although this may not be YOUR problem it certainly seems related. Hope this helps !!!

Specs: Mac mini (late 2014) running 10.12.4 (Sierra), ASUS VW246

Like many other people here, my monitor wakes from sleep, but the screen remains blank. I have to turn the monitor off and on to get the screen to appear again.

@Jimjtron I took your advice and went to Micro Center to get an Inland 24K Gold-Plated Premium HDMI cable with Ethernet (3-pack 3 ft. on sale $11.99), not because it has Ethernet but because it is more "legit" than the unbranded cables that I use.

Now, my screen appears about 26 seconds after waking from sleep... a little longer than I like but it's better than nothing. Thanks for the idea!

Got a Mac mini 2014. Plugged it into my Samsung monitor using an HDMi to VGA connector. Monitor refused to wake up. None of the fixes on this thread worked.

Have another monitor with a DVI input. Got a display port to DVI connector, worked first time.

Mac Mini, model 2014. Connected to Acer XB271HUA monitor. Tried HDMI ---> HDMI, Mini-DP ---> HDMI and Mini-DP ---> DP. Same issue here. My MAC wakes from sleep, but monitor stays off (sleeping). Only workaround for me is to turn monitor off and the on.

Hopefully this issue is solved by now. I had this exact same issue with two different HDTVs...the Mac mini seemed to be unable to wake up the screen from sleep and I would also get inversed colors or a green hue from time to time. After several attempts, including spending a few bucks on high-end HDMI cables, I nailed it about 6 months ago: in fact, you need to carefully select the HDMI port on your TV where you will hook up your Mac. Apparently HDMI ports are not all equal.

On my latest TV, which is a Samsung UHD set, I tried using HDMI port 4 (ARC) and have never experienced any of the above issues ever again. As soon as you touch the mouse or keyboard, the Mac comes to life. Try for yourself !

I'm having the exact same problem. New Mac Mini with 16 GB upgrade. Using the HDMI for the first time with my Acer monitor, but once it goes into sleep I can't get the monitor to wake up very easily. Sometimes turning it on and off a few times will solve it, but sometimes I need to crash the Mac and reboot (not an ideal solution!). I've re-set my energy settings to "never turn off display," but I hope that the Mac folks will take a look at this and fix it in an update.

Got the unit yesterday.

Yes same problem here, I use a Samsung p2350 monitor with Mac Mini 2.6GHz latest model.

I need to press the power button or shake my mouse a couple times or turn off my monitor to get the image on the display back.

This is really weird.

Other problem i've found is sometimes the pictures is all messed up (please see pic)

Anyone have this problem?

I Agree. Try a different HDMI cable. I have seen issues like your screen with sub par cables.

Although I was not having the distorted picture that "tumcubus" has, I also used two different HDMI cables to see if that had caused the problem with my display not waking up (the second was a new Apple cable I bought yesterday). However, the problem persists... .

You are correct that the problem lies with the mini and/or Yosemite; it might be a combination issue. If you do a search here, you'll see there are plenty of posts related to issues just like yours. I have seen no real fixes at this time. My suggestion is to contact AppleCare and/or bring your mini in to an Apple Store or AASP. Until Apple hears enough about this, there probably won't be a fix. I'd also recommend giving them feedback here: http://www.apple.com/feedback/

today I will test the same setup same cables but with my old macbook

to see if it's really the cable or the Mac mini that is causing the not awake problems

and also the messed up color.

Let's see how it goes.