Mac Mini (2012) HDMI losing sync (blank screen/snow)

PS: This may be relevant in pursuing the cause of the black screen/snowstorm/video problem — or may be a rather banal discovery; I don't know which. But I went to the Jacquie Lawson website, found the relevant greeting card, searched for its name on my computer and discovered that in [my computer's name]/Library/Screen Savers there were two screensavers dated 2007 that i must have downloaded from the Lawson website onto my old computer years ago and transferred to my new Mac mini earlier this year along with a lot of my other stuff.

Strangely, they have different names and identifying numbers, but both when double-clicked play the same video (based on one of the Lawson greeting cards). (It is also odd that they must be PPC-compatible screensavers, yet play on the present Intel machine.) Whether this means that a copy of one of them is still embedded somewhere but was not uncovered when i searched remains to be seen.

In any case I am about to write to Apple to request information and a promise of some kind of update, soft or hard, for purchasers of the 2012 Mac mini, and it would be good if all the subscribers to this string of posts would do the same in order to pile on the pressure.

I have a late 2012 Mac Mini, I7, upgraded to 16GB ram and 2 250GB SSD's, this unit has been running flawlessly with 1 Thunderbolt Display for 6 months, absolutly supurb computer, I just lashed out yesterday and purchased a second Thunderbolt display after checking apples support site, it clearly states it will run 2.

First issue: the moment I connected the display, it fired up and worked...awesome I thought, then it starts to refresh, it blanks out for second then back on again, off again and so on, then all of a sudden my original one starts, this is followed by odd graphical glitches and constant flashing, I think ok maybe she needs a restart, so I reset the SMC and the PRAM, reboot the system and...

Second Issue: the main screen starts then goes blank and only the second screen works, im like whattha? so I unplug them, then plug back in and bam they work, then you guessed it, flicker, black, on, off, constantly.

Ok so I decide to test both displays on there own, and yes they function perfectly, so I swap them around, still the problems persist, so I then pull out my Macbook air, plug them both into that and they function perfectly, even with the Macbook display running as well, so its not a "performance" issue as the Mac Mini has far more powerful CPU/iGPU.

So I stumbled upon this MRC stuff from a post in the intel forum and I decide to try removing one of my ram chips, and to my supprise it worked, I tested it a few times and everytime I leave 2 chips in there, I have all these issues with my displays, take one out and the machine functions perfectly.

This makes me quite ****** off, there is no mention of this issue on the support website, the Mac Mini is quite slow at encoding video now with only one ram chip in there, this is an obvious flaw that would have been apparent during testing.

I could have saved my money and waited if I had known about this issue first 😟

Here is copy of my boot rom version

Boot ROM Version: MM61.0106.B03

SMC Version (system): 2.8f0

Have the same set up as yours, although, my second monitor is a Dell. My TB Display would flicker and at times go completely to black screen.

My problem was the 16GB OWC ram I installed. When I removed the OWC ram and installed Kingston ram the problem went away.

I came to this conclusion by following this thread; https://discussions.apple.com/thread/3340067?start=0&tstart=0

I hope it can be of some help.

Ugh, Kung Foo, that's brutally annoying. I REALLY should just bring mine back for a refund and wait until the new ones come out. But I spent two days straight getting this sucker set up and I love it otherwise.

Hmm, very good info, Rcarmic, thank you for that. I just ordered Crucial RAM for mine. Is Crucial on par with Kingston as far as quality? I hope so...

rcarmic wrote:

Have the same set up as yours, although, my second monitor is a Dell. My TB Display would flicker and at times go completely to black screen.

My problem was the 16GB OWC ram I installed. When I removed the OWC ram and installed Kingston ram the problem went away.

I came to this conclusion by following this thread; https://discussions.apple.com/thread/3340067?start=0&tstart=0

I hope it can be of some help.

Same problem -- OWC RAM -- same solution -- replaced with Kingston HyperX Plug n Play 16GB (2x8GB) Kit of 2 1600MHz PC3-12800 DDR3 Non-ECC CL9 SODIMM Notebook Memory KHX16S9P1K2/16.

Thanks Michael and Rcarmic. I'm sending back my Crucial and exchanging for Kingston, just to be safe.

Last night I removed the 16GB of Strotium branded ram and put the genuine ELPIDA 2 x 2GB back in and everything functions perfectly, so I can really blame the R&D guys at apple as everything does work beautifully, I do remember the brand of ram I purchased had "Apple Certified Ram" but was a little more expensive and wasn't actually in stock so I just purchased normal SODIMMS at the right spec, Im about to pick up some of the apple certified stuff today, I'm not sure if its the fact that I have 16GB or if its not compliant, I might see if there is of that Kingston stuff floating around in AU.

Its certainly a strange one, I have built many PC's and owned and upgraded many Macs and usually ram either works or it doesn't, when we talk about OC'ing and performance one understands different ram works better than others but in this case its just stock use, really strange, its like when you switch to dual monitors it uses some area of the ram for screen buffering that it never used before with only 1 monitor and starts to act up, a large percentage of users only have one screen so using any old ram will just work fine, but it takes poor suckers like us to realize "apples" aren't always "apples" pardon the pun

Im glad that we have made some headway on the issue ourselves, after I have purchase different and have tested it I will post here and let everyone know how I went and what type I have used, hopefully our dramas will help others out.

Hay rcarmic

Whats the model number of the Kinston ram you used, I have KVR16S1158/4 or KVR16S1158/8 available, no one is elling the Hyper X in SODIMM around here, there some other brands like Geil and ADATA but I dont want to just by more ram randomly as its hard to return if one has opened it, there snakey about taking it back, I also dont want to lug 2 thunderbolt displays and a mac mini around town testing ram lol

Kinston also have Certified ram but there is non locally, it appears to be same spec as the Strontium certified stuff, CL11

Kingston makes ram specifically for Apple products and it is the "KTA" brand. In my case I purchased 2 X KTA-MB1600/8G.

Cheers for that rcarmic, there doesnt seem to be any available here, at least I know that the 8GB Certified Ram Dimms work, I will just get myself some 4GB ones today and order the 8GB ones over the web, my rig really suffers now with onlly 8GB single channel ram, I usually have multible video encoding threads running will editing other video and its now taking twice as long as normal, Im thinking its more to do with dual channel rather than amount but I do an awful lot of multi tasking on my little power house, cant wait for the new Mac Pro, hopefully my Thunderbolt displays work with no issues on one of them 🙂

I'll throw into the mix here that the 16 GB RAM I bought was from Crucial, which calls itself the "consumer" division of Micron. I called Crucial before getting the RAM and the rep I spoke to said that Micron makes the memory for Apple. Sure enough, when I removed the 4 GB RAM that came installed in my mini, there was the Micron logo, same as the logo on the Crucial memory. Anyway, I continue to have no problems at all, although there is a certain level of discomfort in thinking that I am merely lucky. I am new to Apple, and am a bit surprised that no one from Apple ever seems to jump into these discussions, the way Adobe reps will dive into discussions there. I love my Mac mini, have loved the service at my local Apple store, but am a bit mystified by the corporate aloofness.

The Strotium brand ram I have has Micron chips on it, this ram does not work properly, the ram my mac was shipped with is ELPIDA, ELPIDA is owned by Micron, but the chips are not Micron, there ELPIDA and they work fine, it's a mixed bag of results, post the model number of the ram from Crucial as we now know these chips work as well, maybe someone should start a thread with part numbers that do and do not work, this might save some people some major troubles.

I have been using Crucial memory exclusively in my Macs for a number of years and have never had any issues. I have removed original 'Apple' memory manufactured in Korea (Hynix) and China (Samsung). Companies as large as Apple have their PCB's manufactured to their specs so looking at brand names is probably not the best way to determine compatibility. Crucial does guarantee compatibility with Mac and I've recommended it to others who also have had no complaint.

But getting back to the original thread topic of HDMI losing sync (blank screen/snow), this is NOT a RAM issue; it is the Intel HD-4000 integrated video chip that is the problem with the 2012 Mini. In all likelihood the only fix for this would be replacing the HD-4000 (certainly no software or firmware fix Apple has released has fixed the problem in the better part of a year), which of course would require replacing the entire logic PCB. Intel has been aware of this problem for almost a year based on threads on the Intel site and no doubt the new HD-5000 addresses this issue. I returned my 2012 Mini and recommend others do the same if you really want to get Apples's attention.

I am sorry to come back into this discussion once more, but in the light of recent posts I really need some advice.

It seems to me that putting together the posts that tell of improvements as a result of inserting different makes of RAM and posts that state that the fault lies with the Intel graphics card (and that Intel knows about it), there must be an interaction between the two and the ultimate cure cannot be a simple one of replacing one or the other.

I am anyway not technically competent enough to go in for upgrading my mini, and I do not know at the moment whether I am still within the return period. But I have had the mini since April, have loaded into it a great deal of sometimes very expensive software (Photoshop, Finale, etc.) and by now have a great deal of my own work — writings, correspondence, accounts, musical scores, recordings — stored on it. The problem with the screen (and I only use one monitor) only now occurs once every few days, apparently quite at random. In fact the last time was shortly after I had changed from using the HDMI/DVI cable and started using the DisplayPort one — but with the HDMI cable still in place, plugged into the Dell monitor and lying alongside the DisplayPort one, though, of course,not plugged into the computer, which may be relevant because of the poor screening of the DisplayPort cable that has been reported.

I have now removed the HDMI cable altogether and, as reported above, have deleted the two old screen-savers that appeared when the screen went black for a moment before. So far, after about 24 hours, I have had no more trouble, but in view of the random occurrence of the phenomenon that may not mean much.

If I return the mini (assuming I still can) I shall lose a tremendous amount of stuff — too much, I guess, to back up in the Cloud first. What do you experts recommend me to do?