Q: Thunderbolt Display turns off randomly

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I've been following this post but haven't been really active since my early reports. My late 2012 Mini suffered the original symptom of the black screen and the required reboot. As a refresher, it worked fine with the 4GB Apple memory it shipped with. I upgraded to 16GB OWC and started having the problem. Dropped it to 8GB of OWC and the problem vanished. Swapped in 16GB of Apple memory and had no problems. Replaced that with a second set of OWC 16GB and the problem returned. Replaced that with 16GB of Crucial and haven't had a problem since.

While I am not willing to send my Mini in for testing since it is the main machine here at the house I'd be willing to try the OWC memory as part of a test if that would help move this discussion along. I have had nothing but the highest regard for the folks at OWC. They were understanding and helpful back in January and February when I was first chasing this issue. I continue to do business with them for that very reason. If the updates since the first of the year have solved the problem and exonerate the OWC upgrades I'd be willing to report results back here.

Received 16GB of RAM today for testing from OWC and have it installed as of 11:00am PST.

My configuration is:

Late 2012 Mac Mini 2.6 GHz Intel Core i7

2 x Kingston HyperX 240 GB SSD

OWC 16GB DDR3L PC12800 1600MHz RAM

1 x Apple 27” Thunderbolt Display (2560 x 1440)

1 x Dell 24” 2408WFP Display (1920 x 1200)

So far there are no issues to report.

This is good news - while we'd like to get our hands on a unit exhibiting issue, even better is that the issue is simply no longer an issue under any circumstances. Thank you for your assistance and fast reporting.

OWC memory test update - It is now 24 hours since the installation of the memory and I can report no issues so far. It would be premature at this time to sign off this test as being successful as there were periods with the original OWC memory where I would go a day or so without failure.

I will report back in a week, or earlier, if this issue presents itself.

OWC memory test update - I am pleased to report that after a solid week of testing there were no issues, not even a flicker.

I can only conclude, in my case, that perhaps, there were a batch of chip sets in the first memory I installed in December 2012 that was not quite to spec. I also suspect a design flaw in the HD4000 chip set contributed to this fault as we still have the HDMI sync issue still unresolved.

I have previously posted here with the flickering issue with my early 2011 macbook pro. I had assumed this couldn't be a memory issue as, despite installing new crucial memory, I was sure I had the problem before the memory upgrade. I must apologise as I today reinstalled my original ram back to 4gb and no flickering so I have ordered more memory from the apple store instead.

Sorry that my earlier post may have been misleading and I hope this update helps.

I have the same issue though I only noticed it when I hooked up an external display. Can go hours without an issue then random black flickers.

I don't remember where i got the memory from, may have to try the Crcual brand.

VERY frustrating.

I see that people have had success with teh Crucial brand but for me it appeared to be that causing the issue - at least it resolved when I installed the samsung ram that came with the macbook pro.

FWIW - we can effectively guarantee our memory compatibility and full Apple spec there for. I apprecite the recent testing done by a couple customers who had experienced past issue where our Memory was in the mix, but have been able to confirm no issue in the present day with current product provided. The Mac mini has it's own challenges likely related to the HD4000 video - even where we don't see similar issues with other HD4000 video equipped 2012 MacBook Pro 13" models.

I will add though that there are a lot of moving pieces. I use currently use a Retina unit that is fully factory (memory factory soldered) and while I've had no issues with my single display and dual display setups at two locations - a location I travel to and use an iMac in display slave mode, just last week this setup had a black/flicker on-off about once every 1-2 hours. I didn't have to restart, the display came back on as quick as it shut off... This was with a 2 Meter Apple Thunderbolt cable and in this case I wonder if just a signal issue?

In the case of the Mac mini, and we're still working to have a unit today (note Apple has continued pushing updates that do impact this issue for all the TB Mac models) where we can get the original reported issue to surface around a memory set. In that case, the report was consistently here with two displays and when the display went black, only a restart would bring it back. FWIW - in 2012, I did see the same kind of issues and lots of general frustration with my Retina as well - although usually the main issues were at initial hot-plug in. Today, things pretty stable.

If your issue is a periodic on/off flicker - I'd look first to the cabling. In the case of mini-Display port adapters especially, we have seen issues corrected by replacing a cheapie with one of our NewerTech or Apple adapters fixing that and other video issues.

The wierd thin is it's ONLY the Thunderbolt display that flickers, NEVER the second display. What could cause that? And its conencted with the builtin Thunderbolt cable

Just to update. I today received 8GB ram from the apple store to replace the crucial memory 8GB and no flickering as of yet. Previously I had flickering every 2-3 minutes or so, so it seems my case of flickering is also down to a memory issue.

(Macbook pro early 2011 2.3GHz i5)

Just out of curiosity... which BRAND is your Apple RAM?

I've always had good luck with Crucial and have experienced no problem with my TB Display and LATE 2011 MBP.

Clinton

It was adding Crucial to my late 2012 Mini that CURED the probem. Not a hint of blackout since that change.

I am not sure what brand it is (it was branded an apple sticker on the ram on the box says 1 Infinite Loop Cupertine).

I realise Crucial is a great brand of ram and it could have simply been the ram I received that was faulty.

I hope that helps.