New 27" Thunderbolt Display Flickers when attached to new 27" iMac

iTech23, have you had a chance to install the Samsung chips? Any luck resolving this issue?

Hi,

I checked the Samsung memory and is the same memory that came originally with the machine so I was really happy because I thought it was going to work fine but unfortunately after using the machine for 10 minutes I got the first flickering on the thunderbolt display, the machine is at the Apple Store right now. I'm starting to think that this is an issue with te computer and not the memory but it happens with the combination of 16gb + the thunderbolt display, it's been over 6 months since I started having this issue so the machine is not leaving the Apple Store until I got a resolution on this issue.

At my company we have a number of early 2011 Macbook Pros. Those that were upgraded to 16G memory ALL show the flicker issues with Thunderbolt displays. The laptops not upgraded to 16G RAM do not have the flickering. Additionally we've found that the flickering is worse during memory-intensive work (e.g. Photoshop)

I bought a brand new i7 27" iMac with a 27" inch thunderbolt as a second display and notice the flicker immediately. The machine has 24Gb of RAM. I opened a ticket with Apple Warranty (319522140) and worked with them for several hours to resolve the issue. No luck.

The support person eventually told me that a thunderbold firmware update was required. We checked and found that my new display had come with the correct version (1.1 is my recollection).

The flicker comes and goes at times more persistent than others. Its hard to put a finger on what might actually cause it. The machine is fairly lightly used so I don't think computation resources are what cause the problem. There is a thunderbolt drive on the iMac as well (using the second TB port) but its used only for timemachine. The flicker happens often when there is 0 disk activity so I don't think that is the problem.

Anway... looking for a solution. Its irritating to have spent over $4K on a machine with gorgeous 27" displays to have it flicker.

look forward to a resolution to this issue.

--luis

Thanks for your post. I suspected as much but thought I would post anyway given that all my hardware is spanking new.

I did call OWC to ask if they knew of the issue and if they had any work arounds. The tech that I spoke to claims that no one has reported the problem. I had him search their knowledege base for the words "filker" and "thunderbolt" and he found no hits.

I know other users have had discussions with OWC (i purchased 24Gb of RAM from OWC) but it seems they have not taken notice. Here is what I got from OWC to no avail...

---

I recommend trying to clean the memory module. Take a clean pencil eraser and gently rub it along the metal contacts on the memory and follow that by using a microfiber towel along with rubbing alcohol to clean the metal contacts on the memory, this should insure that the memory is getting a solid contact with the computer

If that doesn't resolve the issue, I would try both and SMC and PRAM reset.

SMC reset: http://support.apple.com/kb/HT1411

And

PRAM Reset:

1) Start the machine while holding down the Option-Apple-P-R keys

2) Wait until you hear the 3rd startup chime, then let go of the keys and let the machine boot up.

Lastly if the issue is still unresolved, I recommend running an application called Rember. Rember is a free download at http://kelleycomputing.net:16080/rember/. Once you have it downloaded please run a 3 pass test. This application will let us know if any issues are present on the memory modules.

I look forward to your reply.

Sincerely,

OWC Ben

Technical Customer Service Representative

Other World Computing, Inc. (OWC)

OWC.net, Inc.

2650 Bridge Lane

Woodstock, IL 60098

www.macsales.com <http://www.macsales.com>

1.800.275.4576

---

I guess I will need to live with the flicker for the next 6 years (that is how long I had my mac pro) and then be a bit more carefull when I purchase my next system.

--luis

OK seriously? OWC needs to know about this. It's surprising they haven't already. I went through months of Apple Support calls with the engineering dept. at Apple regarding this issue and spent countless hours troubleshooting and found that it was indeed the RAM. But I'm pretty sure it's not specifically OWC's RAM, as this issue seems to be more about the amount of RAM being >8GB. It's just irritating that OWC has been advertising 16GB+ as being no problem for Mac Mini/iMac/MacBook Pro when that is now CLEARLY not the case.

This problem has been around for quite some time now.

Surprisingly, as far as I know, none of the big Mac websites out there like 9to5Mac or Macworld have taken up the issue and featured it on their websites. Nor has Apple or the RAM manufactorers have taken notice.

These flickers mostly occur on exceeding the suggested max RAM, however, there are some reports from people, who have excactly the same issue with a TBD and an Air or MBP for instance, running with factory built 8GB RAM or less.

I ran every test known to man (well to me) in order to figure out, where exactly the problem is - no avail.

First I thought, the problem only occurs on Macs with > 8Gb RAM, but I was proven wrong, since I also got these flickers on my Air. Then I figured, it could be due to the heavy load on the GPU (especially during playing flash content). However, I'm also having blackouts after booting up, when the computer is still idle with virtually no stress on the GPU.

As long as there is no permanent damage to either computer or display, I guess, I can live with it, however, these flickers REALLY annoy the crap out of me.

Below is a console screenshot, displaying flickers during watching flash content.

On my 27" iMac and Apple 20" Cinema Display (connected via an adaptor t the Thunderbolt port) I thought I had got rid of the flickering by setting the desktop to a plain blue color. It has certainly reduced the incidence of flickering when I drag a file out of a folder onto the desktop.

It hasn't completely got rid of it. In particular, dragging something to the trash can cause it. In ALL cases, I can reduce the flickering to zero if I

- unplug the ACD from the iMac

- move the file SLOWLY onto the desktop

The latter seems especially weird. It suggests a graphics card problem rather than CPU or RAM. (I have 16Gb but installed from the start so can't compare with base level RAM.)

Unfortunately this issue doesn't really point to bad RAM by any one manufacturer (OWC for example). Multiple brands exhibit this behavior. I've been watching this thread for months because I wanted to upgrade my 2011 MBP to 16GB RAM. But Apple says it doesn't support 16GB RAM...because it doesn't support it.

I feel sorry for those of you who are "living" with the flicker. That's unacceptable to me, but to each their own.

It officially got annoying!

Last night, when I ran Data Rescue on my friend's hard drive, Console presented me this in the morning:

Yes, confirmed. That event is posted in the log every time the flicker occurs. DP Link = DisplayPort Link

So... my 27" TB display bit the dust today. In the middle of the afternoon while not doing anything really (doing email) i got the "gray" screen of death on my mac. I had never seen that before. The mesg stated that my mac had died and that i needed to power cycle it. So I did. The TB display has not worked since. The screen blicks dramatically and the images on the screen are totally distorted. After a while the screen goes black. The same behaviour happens no matter what mac i connect the display to. So it seems that the display has sufferred from a hardware failure 2 months after it was purchased.

I have to wonder if the failure is cased by the intermittent flickering on the display since day one.

I now have a new all to apple care for the repair/replacement of this display.

So... the flickering is bad.... My question to the community is... does the flicker only happen with the thunderbold display? Will the flickering go away if I replace the thunderbold display with and older cinema display such as this one?

http://store.apple.com/us/product/MC007LL/A?fnode=53

or is the issue with thunderbolt interface itself where the mini-DVI would plug into?

i can live with slower perfomance on the second display but its hard to deal with the flicker.

any advice is greatly appreciated.

The flicker is gone!

so as stated a few posts ago I had a catastrophic failure on the display so I called apple and scheduled a on site service repair. The repair guy showed up here on Monday morning, took the display appart, and replaced everything inside. He replaced all the boards and also the LED screen. He reasembled it and I had it back on my desk by late morning on monday. The fantastic thing is that I have not had a single flicker, not one, since I powered it up. It is now midnight on Tuesday so its been about 36 hours since I powered it on.

Summing up with the new revamped thunderbolt display I am not getting flicker on my i7 27" iMac with 24Byte of RAM.

So... it seems that apples new hardware resolves this issue.

Lets hope it stays that way.

--luis