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

Did a complete shutdown of iMac and Thunderbolt display...this time with no USB devices attached...

Starting up iTunes plays music for maybe one minute over the Thunderbolt display loudspeakers and then stops...

Interestingly the kernel log shows following then:

Oct 28 15:09:46 imac27 kernel[0]: USBF: 241.174 The USB EHCI driver found a controller at the wrong PCI Power State (0xffff) - fixing that issue.

Oct 28 15:09:46 imac27 kernel[0]: USBF: 241.288 AppleUSBEHCI[0xffffff8025be8000]::UIMInitialize - could not get chip to come out of reset within 100 ms

Oct 28 15:09:46 imac27 kernel[0]: USBF: 241.288 AppleUSBEHCI[0xffffff8025be8000]::UIMInitialize - Error occurred (0xe00002c9)

Oct 28 15:10:21 imac27 kernel[0]: USBF: 275.527 The USB EHCI driver found a controller at the wrong PCI Power State (0xffff) - fixing that issue.

Oct 28 15:10:21 imac27 kernel[0]: USBF: 275.641 AppleUSBEHCI[0xffffff802a538000]::UIMInitialize - could not get chip to come out of reset within 100 ms

Oct 28 15:10:21 imac27 kernel[0]: USBF: 275.641 AppleUSBEHCI[0xffffff802a538000]::UIMInitialize - Error occurred (0xe00002c9)

Oct 28 15:10:46 imac27 kernel[0]: USBF: 301.293 The USB EHCI driver found a controller at the wrong PCI Power State (0xffff) - fixing that issue.

Oct 28 15:10:46 imac27 kernel[0]: USBF: 301.407 AppleUSBEHCI[0xffffff8025a82000]::UIMInitialize - could not get chip to come out of reset within 100 ms

Oct 28 15:10:46 imac27 kernel[0]: USBF: 301.407 AppleUSBEHCI[0xffffff8025a82000]::UIMInitialize - Error occurred (0xe00002c9)

Oct 28 15:11:04 imac27 kernel[0]: USBF: 318.586 AppleUSBEHCI[0xffffff8025a82000]::UIMInitialize - could not get chip to halt within 100 ms

Oct 28 15:11:04 imac27 kernel[0]: USBF: 318.586 AppleUSBEHCI[0xffffff8025a82000]::UIMInitialize - Error occurred (0xe00002c9)

Oct 28 15:11:04 imac27 kernel[0]: USBF: 318.702 AppleUSBEHCI[0xffffff8025a82000]::UIMFinalize - could not get chip to halt within 100 ms

Then no further USB entries in the logs...

Hmm...

Display still flickers after this weeks update...

Opened up a ticket with Apple but no reply so far...

Getting worse now...display gets dark for several seconds now...

and during that time the mouse is less responsive!

Message was edited by: davorin

I'm still having the same problem here, I applied all the updates and got a new thunderbolt display as a replacement.

I also have connected a regular 27" Apple display and is working perfectly fine.

I'm still having the same problem even after installing the update that was supposed to fix this issue, anyone else still having the black screen/flickering issue?

Apple already replaced my Thunderbolt display and now they want me to take my 2 months old iMac to an Apple store so they can test it but I don't feel confortable doing that specially since it's a new machine.

The EFI and firmware update seemed to take care of it for me. I've not had any flickers since.

Thanks for your reply, unfortunately I also applied both updates but I'm still having the same issue.

Thanks.

This may only be circumstantial evidence, but...

I've had my Thunderbolt display since the day they were released for sale. Never had a single flicker or blackout.

Until two days ago. It now flickers every few minutes, totally at random.

The difference? I installed a new RAM upgrade in my 2011 Mac Mini. Coincidence?

I know Mac Minis (and some MacBook Pros) use system RAM for video RAM. Perhaps not all RAM chips are fully compatible and may cause irregularities in video performance via Thunderbolt?

Or perhaps it's just a coincidence.

I suppose I could swap the RAM back to the factory set of chips to test this theory. But I'd have to watch it very closely for several days to be (reasonably) certain.

This theory may help explain why everyone who has their display replaced still has flickering problems. It's not the display, it's the computer? Although this could be determined by connecting a "faulty" Thunderbolt display to several completely different Thunderbolt Macs and see if the problem persists.

(All software updates are installed. I've unplugged and re-plugged the Thunderbolt connection a few times. There are no peripherals connected to the display itself.)

Same here, when I got my new iMac I upgraded the RAM to 16GB.

I ordered mine from the factory with 16 GB (did not upgrade it myself) and had the flickering problem from day one.

Very interesting.

It was 16GB that I upgraded to, and that's when the flickering started.

Here's the kicker: Just before that, I had 8GB in for several weeks, and NO flickering.

Am I sensing a trend here?

Just FYI, I have a 2011 MacBook Pro which has been maxed out at 8GB RAM and I've never experienced the flicker on my Thunderbolt Display.

Interesting findings here!

What happens when you take the RAM upgrades out?

I'm not about to put the old RAM in just to test this. I got the upgrade because I needed the memory - the machine could barely run on the stock 4GB with the apps I use.

I've gotten into the habit of firing up Console.app to check system logs immediately after I notice flickering.

One thing I've seen to be consistent, is this line showing up in the system log every time:

kernel: Restoring DP Link

Google doesn't help regarding the flickering, but informs that "DP Link" is the method in which video signals are sent over Thunderbolt cables. I think it means DisplayPort Link, from Googling 'DP Link fail' and other related searches - and it seems other brands of monitors and PCs/graphics cards have had similar issues. So I'm guessing that something is causing the DP Link to fail sporadically. Could be software (ie, the OS).. or could be hardware.

Also, for anyone who is curious (Hello: Apple tech support!) as to what the flickering looks like, this video sums it up:

http://vimeo.com/21173450

(not my video.. just found it)

Well, my display had been fine since that original firmware update. I ran software updates today however and there was another firmware update. I told it to go ahead and install. It ran but then said the update failed.....and now the **** flicker is back! And of course, when I check for updates now, it says there are none.