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

This has been driving me nuts since I got my Mini in late November.... I did do the 16GB upgrade from OWC, so... I guess we're stuck until Apple finds a fix.... Bummer!

Thanks for pushing them on this!

I am really happy I came across this thread. It's a true blessing. I was ready to purchase the 27" Thunderbolt Display for my Mac Mini (with Corsair 16GB), and now I know I still have to wait ...

I use the TB display with my mac Mini and it works great. No issues. The "fast" speed of the computer should have no impact on the display working or not. The flickering is caused by something else.

@tbirdvet

How much RAM do you have?

Started with 4GB (stock) and TB display and all worked great. Recently upgraded to 16GB for faster processing and all is still great. I have the I7 2.6Gz Mac Mini

@tbirdvet

I have 2.3 Gz Intel Core i5 with Corsair 16GB and a generic Samsung monitor, which I was going to replace with a 27 inch TB. After reading this thread I was going to wait till June, as Mac Rumors predicts something new to happen (http://www.macrumors.com/2013/01/14/apple-thunderbolt-display-supplies-begin-run ning-short-at-third-party-resellers/),... but now I am confused...

I'm sure the next TB display will be built on the new iMac chassis which will be thin and Apple will delete the FW800 port on the present TB display but if needed you could use a TB port to FW adapter. I got tired of waiting and I knew the present design was proven out so I bought the present TB display and I use the FW800 port for my External HD (Time Machine)

I bought a 27" TBD for work and liked it so much, I decided to get one for home. It flickers occassionally when I plug in to one TB port, but if I switch to the other one it seems to settle down. Note this doesn't happen at work, which makes me think the quality control on the monitors may not be good. If it keeps happening I'll have to take it back!

I'm using a mid 2012 MacBook Pro Retina, 16 gb ram

@orchetect: have you seen any improvments with the latest updates coming from Apple about the 16 GB two monitors issue? It seems you were saying that using one TB monitor with 16 GB has no flicker, can you confirm that?

Thanks!

My monitor has settled down. It's working consistently well now in either port. If it changes I'll update the thread!

C

To anyone who is still having this issue, try resetting the PRAM. The PRAM stores hardware data as well as video data in it, and if it's still using the PRAM data from older RAM cards then this can cause a minor incompatability, resulting in graphical errors such as the described flickering.

You can reset the PRAM by following these steps:

1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.
7. Repeat this restart process three times to fully clear the NVRAM / PRAM.

Thanks MrMusAddict, resetting PRAM did the trick for me with my MacBook Pro 13" connected to the Thunderbolt Display.

Martijn

Thank you sooooooooooo Much... this has been driving me nuts and put me through 2 cables trying to figure it out, but this seems like it may have worked!

Excuse me, for may be dumb question, but reset PRAM operation need to be done without connected thunderbolt display? Or I need connect it and then reset NVRAM / PRAM 3 times?

I reseted it one time, but it didn't make the trick ( Monitor is still flickering

Jeff,

I did it when it was connected. It seems to have cleared things up for now, but I have done this before. For me this has been doing it since I bought it and my laptop, which is a macbook pro w/retina w/16GB ram. Got them both when they were released. With my flicker, it ends up scrambling/snowing up then shutting off. It is annoying. It's not only with my laptop, I have a mac mini with 16GB ram and it does same thing.