Mac mini 2014 won't wake monitor via HDMI

I also have the same problem. It is intermittent. I thought I solved it by selecting the Bluetooth preference: "Allow Bluetooth devices to wake this computer" - but the problem still randomly occurs. I've tried every solution I've stumbled across.

This is apparently an unresolved bug. Maybe in the next update? The one sure-fire way to avoid this for me is to turn the monitor off when I leave the computer for a while. When I turn it back on manually everything's fine. A bit inconvenient, but it works.

I spoke with AppleCare today. Spoke to a pretty knowledgeable guy who understood things like HDMI pin signals. He says that the MacMini Late 2014 is using the HDMI 1.4a standard, and that the Acer H233H monitor that I have is probably using an old HDMI standard. He says he found other people having problems with the Acer monitors when they are using Windows or Linux. Two possible fixes are to turn off Energy Saver (not recommended), or just get an HDMI->DVI cable and that will fix the problem.

My next test is to try hooking up a TV that I have with an HDMI connector to see if the same thing happens or not.

I have an H236HL but it is probably using the same old connector. I did try an HDMI-DVI cable but had some weird color issues - but I'll try it again. I did originally have it hooked up to a Samsung HDTV and had no problems.

Mine is a new Acer monitor, S277HK and it was behaving fine with my new MacMini Late 2014 before the El Capitan update. TBH I don't have too much of a problem with it - just that it takes ages for the display to come up once I've clicked the space bar to wake the monitor. However, I'll try the HDMI cable that came with the monitor in case that's more compatible with the standard than the one I bought (as info didn't mention I would be getting a cable with the monitor package).

Apparently it has HDMI 2.0 rather than 1.4a!

OK - tried the HDMI-DVI cable again (Amazon Basics) and the first time it came out of sleep, the colors were way off. I made sure the connection on the monitor was secure and locked it down - and have not had the color problem again - and have had no problems waking from sleep since. Have probably tested about 6-7 times, including overnight.

I also seemed to have fixed the WiFi not connecting after sleep issue, but I guess that is for another thread.

I'm now convinced that my problem is with the Acer monitor. I tried the MacMini Late 2014 with a Pansonic TV, and it wakes up fine from sleep. I then hooked up my Acer monitor to a Windows laptop with HDMI, and the Acer monitor does NOT wake up from sleep with the Windows laptop.

So it seems there isn't much I can do except get an HDMI->DVI cable to use with the monitor, or just get used to power cycling the monitor each time I wake the Mac up from sleep. 😟

Just got the latest El Capitan update. Didn't fix the problem.

Did you try using an HDMI to DVI cable?

I have the HDMI to DVI cable now with my Mac Mini and ACER monitor. Some times when I wake the Mac Mini up, I get the screen with the login prompts. Other times, I get a black screen, but I can type my password and log in. I'm not sure why it works some times and doesn't work other times.

The only other thing I can think to share is - under "Energy Save" - the only box I have checked is "Put hard disks to sleep when possible."

We were having the same problem - Samsung monitor would not wake up from sleep with a brand new Mac Mini connected by an HDMI and DVI adapter.

We tightened up the connection and it worked 2/3 times (it hadn't been working at all before). We set it to not "fall asleep". We will see what happens.

Thank you all for keeping up with this post so we could benefit from all the troubleshooting you've done!

Garbage. We were having the same issue over a year ago and I hoped they had fixed it by now. Our new Mac Mini has this same HDMI issue as the previous one, and after it intermittently working and being able to wake from sleep it is today not waking at all.

Hello,

same problem here. Mac Mini (latest 2014, El Capitan 10.11.2) randomly doesn't wake up external HDMI monitor (BENQ). Besides, when it happens, my monitor power button doesn't even work, so I have to power cycle my monitor for it to work.

It's annoying and Apple Support should be release some kind of patch to fix it. (I really hope).

BR,

This issue was resolved for me with the model I bought on January 31, 2015. I was having the same problems as mentioned here, so I returned it, and re-purchased the computer once the next OS X update was released. I have not had any problems since.

I will reiterate that this may be model specific. However, there was an OS X update released YESTERDAY, which may have resolved this problem, for those still experiencing it. I'll be interested to hear if it does.

Best of luck!