Q: Mac mini 2014 won't wake monitor via HDMI

Have same problem, but WORSE.  Fails to send signal to monitor BOTH on new boot, AND on trying to wake from sleep (both situations about 75% of the time). MacMini Oct 2014 with OS X 10.2  From day of purchase, no signal to monitor using DisplayPort to DVI on HP Monitor.  Checked settings on monitor, no change.  Moved mouse around. No change. Clicked keys on keyboard, no change.  Held ON button of Mini to cause a shutdown and reboot.  After about 3 tries, finally got a signal to monitor and all operated well until I turned it off.  Purchased a new and expensive NEC Multisync EA244wmi monitor, no fix.  Tried changing to a HDMI cable, no fix.  Tried various energy saver settings, no fix. I have to deal with this 5 days out of 7. What I get when turning it on in the morning is hearing a ding dong, the HD running, but nothing more happens, no Apple logo on the monitor, which shows a no signal alert.  When trying to awaken from a sleep, it is a dead brick.  In both cases, I keep drying a shutdown and waiting 10 seconds to boot up again.  Sometimes it does, sometimes not.

The Apple site support references, about not awakening from sleep are mostly about laptops, are nearly useless.  And no helping points on the problem of unable to send signal to monitor when doing an original boot.  I have read strings of posts about these issues and tried various ideas and there has been zero improvement.  I am very, very disappointed in the MacMini, as I had a MacBook Pro prior which had only 1 problem in 4 years.  With my MacMini, right out of the box, that won't send a signal reliably to the monitor, there is nothing to see to do a diagnostic - it is a brick.  Rebooting 3 or 4 times, unplugging cables and replugging, when I took it out of the box, in frustration I came close to taking it back to Apple under warranty, a 50 mile trip which is why I have not yet done it.  After hassling with this for a few months, I am getting ready to return it under warranty, and to refuse a like replacement, based on what I  have read here - and then consider reverting to a MacBook Pro or an iMac.

I'm having the same problems with a brand new Mini running Yosemite.

The only difference is, that I'm using a VGA monitor driven from a

Thunderbolt port via an adapter to VGA. I occasionally see the messed

up colors on the display and the only way to clear it is to restart. This

occurs after a wake from sleep.

Same problem with new 2014 mini (OS 10.10.3) <> Asus MX. Called Apple support and this OS fix from Kieran worked.

From OS Library, trash

- /Library/Caches

- /Library/Launchagents

- /Library/Launchdaemons

From user library (hidden in Yosemite(!) - requiring you to select Go and hold cmd to reveal it in dropdown menu); trash

- ~/Library/Caches

- ~/Library/Launchagents

Restart with an SMC reset. Empty Trash. Voila.

Its worked for me with 2 test Sleeps from dropdown.

Not tried it overnight yet but its looking very hopeful...

unless I have to go through the process every day!

Looking forward to trying this today, just picked up my refurbished late 2014 Mac mini on Monday and my Sony VGA monitor has failed every time to wake up from sleep, I would have to disconnect the thunderbolt adapter from the Mac mini and plug it back in to wake up my monitor

When I first took the mini out of the box to set it up with my Sony monitor, it wouldn't load setup and kept restarting, I had to connect it to my smart TV through HDMI to get setup going, Apple must really not want us to use third party monitors

Next day report ...Went to wake it up from overnight sleep - it didn't work. The problem persists with an added issue - the monitor wakes up in greyscale. It returns to colour after a few secs. Pointer/cursor wakes up about 30 seconds later still. Very irritating.

Will call Apple Support again sometime soon ....

P.S. if you do try this Apple Support so-called fix, I must make clear that the Library files to Trash are HD>Library & HD>Go+alt>User Library and NOT System Library. Do not touch those.

PPS When I trashed the files, I then lost browser functionality ( cue 2 hours with Apple Support ! ). Bad luck for me. We finally figured out the issue. I had Glimmerblock (http proxy adblocker) installed and when I ditched the Launch files, Glimmer stopped me getting into websites - so if you have Glimmerblock installed, DO NOT trash these files!!!

It seems that I've solved my problem. (knock on wood) I'm sure exactly what did it, but I did the following

with my brand new Mini;

SMC reset.

Zapped the pram.

Replaced my wireless keyboard/mouse's receiver with a newer model. (Logitech S 530 wireless desktop)

Trashed the MacLoc me application after remembering that it didn't

play well with Lion for the short time I had it on my older model iMac. It was identified on this discussion board

as the culprit for several problems .

Reset the Energy system prefs to default .. disabled screensaver.

My Mini now wakes dependably and the video aberrations from wake I was seeing have not resurfaced.

Thanks to dumb luck, a little research, experience and The Force, I guess.

You could have a USB wireless connected to your wireless keyboard and when you press enter it would wake it up automatically. I do this all the time

I think I may have identified the cause of this problem, if not a cure for everybody.

Have 2 mac minis, one 2 years old, one 2 weeks old. Using one with a LG UDH TV screen with HDMI inputs (no Thunderbolt or DVI) and with a LG 34" UHD monitor with 2 Thunderbolt and 3 HDMI inputs.

The 2 week old (as at May 2015) mini's HDMI port does not have the sleeping monitor problem - that is the only one that will work with LG TV reliably.

The 2 year old mini's HDMI port does have the problem and no combination of cables using HDMI> to anything connecting the LG TV seems to fix it. The brand new port must have a different signal output as the LG TV never goes wrong with that.

My suspicion is the earlier mac minis HDMI ports do not conform to the requirements of some LED TV screens - I think all of the traffic in this forum on this topic may have had an effect on Apple changing the HDMI port settings.

Now if Apple would just bring back a quad core mini, that would be great !

Mini still not waking the monitor reliably (Thunderbolt to VGA via an adapter) I've found that unplugging the cable at the MIni's Thunderbolt port and plugging it back in wakes the monitor every time (so far)

Conclusions; it's not a problem isolated to HDMI driven monitors. It's also a VGA monitor issue. Updating to 10.10.2 or 10.10.3, which is what my Mini came with out of the box, is not necessarily a fix. Apple doesn't have a fix. Wish I'd bought another iMac.

I'm on a late 2014 Mac Mini (1.4ghz) using an HP w2207 monitor with an HDMI to a DVI adapter. I move my mouse and keyboard, the sleep light on the Mac stops blinking, but the monitor doesn't come on at all.

Yeah it is not monitor specific. I've had the issue both on a Benq monitor as well as with Apple's Thunderbolt Display.

About a week ago I changed my Energy Saver settings...checked the box "Prevent Computer from Sleeping automatically when the display is off" and haven't repro'ed the issue since. Fingers crossed. I don't think it's really going to be that simple though.

Anyone who hasn't already bugged Apple about this should do so. The more they hear about it the more likely they will try to fix it, one hopes.

I took Andvari's suggestion and turned off my "Prevent Computer From Sleeping Automatically When The Display Is Off" option

and it now seems to wake dependably. However, I still have the problem mentioned by only a couple of the others.

That is, when the monitor comes on, the colors are "weird". It almost looks like "invert colors" is selected in the accessibility panel.

They look very overdriven.

If I unplug the monitor at the computer, at the adapter or at the monitor, the problem clears when I plug it back in.

I've been snooping around the forum a lot in the last week, looking for answers, or direction or something, particularly

since I read (but can't confirm) that 10.10.3 release notes said that there was a fix included for the monitor not waking

problem. Somewhere in all that reading, I saw mention of a speaker system causing or affecting the color and the

not waking the monitor problem.

I tried unplugging my speakers before sleeping the computer, and what do ya know!? It wakes properly and with normal color.

I plug the speakers back in and go on my merry way. This only works if the speakers are unplugged from the headphone jack.

If I power them off or unplug the power supply, the computer still comes back with the wonky colors.

While thinking about the similarity between what I'm seeing onscreen and what the screen looks like with "Invert Colors"

activated, I decided to take a look at the accessibility panel while the colors were wonky. I clicked "invert Colors" and I'll

be darned if it didn't clear up the color issue. Curiouser and curiouser!

I haven't entirely ruled out a compatibility problem between the Mini and my Sharp monitor. It IS an older 17"

4X3, or whatever 9X16 isn't, LCD display.

However, it has worked just fine with several other computers. And given the variety of monitors that folks are using

with their Mini's and still having problems, I rather doubt that the Sharp is the real issue.

I guess I'm going to have to call Apple and at least try to get them to open a case. Maybe my findings will poke an

engineer in a brain cell and he or she will come up with a VOILA moment.

If this is a known problem with the Mac mini and the second level support staff and the Genius bar have no clue about it.  I bought a Mac Mini from Amazon and used an older Asus HDMI monitor.  It would take minutes to wake up so Apple Care convinced me to buy another monitor.  The new Samsung monitor was actually worse and after another call to Apple Care they had me reinstall the Operating System to no avail.  I returned the first Mini, got a new one and went to the Genius bar.  We tried everything and the only thing that worked was the Mac monitor at $1000.  I'm close to buying an iMac but I'm very dispirited in Apple.  If I didn't know better I'd swear I was dealing with Microsoft.

I have a workaround I tried that others may be interested in. The problem might be with the monitor's compatibility with an HDMI cord (and possibly with OS X).

I noticed that my monitor didn't have an HDMI input in the back (possibly because it came out in 2007). The make and model number of my monitor that was experiencing the problem was an HP W2207. I was using an HDMI cord out the back of the Mac Mini into a DVI converter and then into the monitor's DVI input.  I'd put my Mac Mini to sleep using that setup and the machine would stop blinking when woken up, indicating that the system is back from sleep, but my monitor didn't come on when I pressed the spacebar or wiggled the mouse.

I then bought a Mini Display Port to VGA input adapter for the Mac Mini. I hooked up my monitor using the adapter and a regular VGA cord into the machine and  now the monitor comes on when I wake the Mac Mini from sleep (and shows the welcome screen quickly). Problem solved for me! The screen cut off some of the top of the OS X desktop, but it auto adjusted just fine after a few seconds.

My guess: the monitor simply didn't support an HDMI converter or HDMI cord because the monitor was older and didn't have an HDMI port built into it. It could be a problem with DVI connection between the Mac and the HP monitor or something to do with the HDMI to DVI conversion between the two. I came to this guess because the Mac Mini woke up a recently new Vizio HDTV and displayed the login screen within a few seconds of waking the machine. However, The monitor I was having problems with in OS X woke with no problem when plugged into the HDMI port of an Asus laptop running the latest version of Windows 8.1. I might add that the fastest spacebar press/mouse wiggle to monitor waking up time of the 3 tried methods is with the Mac Mini using the Mini Display Port to VGA.

I hope this can help somebody!

This is my third post. After abortive trashing of selected User Library files as advised by Apple the other week and then another session with Apple helpdesk which was escalated to higher powers (no reply from them...) ...what has happened is that THE PROBLEM HAS GONE AWAY. I have done nothing new.

About a week or so ago, to my astonishment, my machine woke-up straight away from sleep and has been doing so very day since, so now I am confident enough to post this news. Doesn't help people still suffering - but my mac mini (late 2014) <HDMI> ASUS monitor is - for no apparent reason - now working fine. (?)