Graphical issues with 2011 iMac and Lion

Andrew...

Regarding your computer hangs at grey screen, do you have any external USB devices or drives plugged in? If so, disconnect and see if that fixes the boot problem.

Happened AGAIN. For some reason it has been happening more frequently recently.

iMac 27", 4GB RAM, 1TB + 256GB SSD, AMD Radeon 6970 2GB, 3.4Ghz i7

It shows up on the external monitor, which is an I-Inc iF281D if it matters, as well as the menu bar and Dashboard on the built-in iMac display. I really want this problem fixed; it's getting very very annoying. I switched away from Windows to avoid problems like this.

http://imgur.com/NLjmT

Has this fixed the issue for anyone?

http://9to5mac.com/2011/09/29/apple-quietly-issues-firmware-fix-for-thunderbolt- flickering-issues-on-27-inch-led-cinema-displays/?utm_source=feedburner&utm_medi um=feed&utm_campaign=Feed%3A+9To5Mac-MacAllDay+%289+to+5+Mac+-+Apple+Intelligenc e%29

this thread is about the iMac not the cinema display...

I have an iMac 27 and the cinema display and have the problem on both!!

Well, I have thought that when I updated the iMac to 10.7.1 I wouldn't have to worry anymore about that issue... wrong! When doing video editing, I still have these ugly pixelated icons and videos playing horizontal green lines with this annoying flickering effect! ****! How can you run your business like that! And not a single response from Apple on this issue. Need a coffee, what else?

I was able to recreate a glitch and I was watching the temperatures closely using temperature monitor. And at about 174 degrees Fahrenheit, It started… I have a short video of it up on youtube. http://www.youtube.com/watch?v=5YMrU0xF_8c&feature=youtube_gdata_player

Kind of psychedelic, I know, but these are the icons I see when using cmd-tab to switch applications. They almost appear iridescent. I also have unreadable, pixelated rectangles that take the place of the text on the menu bar when I click on them (File, Edit, View, etc.).

27-inch iMac (mid 2011), 3.4 GHz Intel Core i7, AMD Radeon HD6970M 2048 MB, OS 10.7.1 (11826)

I'm having the same problem. Up until now, I wasn't sure whether the problem was due to Lion or hardware related but after reading through this community, I'm relatively certain that it's LION related. When I purchased the computer, it had Snow Leopard installed but I immediately installed Lion so I had no history with the system with the prior OS. What further complicates the matter is that this system was restored from my previous systems Time Machine backup so it wasn't a clean install.

I hope Apple gets this matter resolved quickly.

Lastly but unrelated....

Rest in peace Mr. Jobs....

These are 2 screen shots from my iMac.

I have recently noticed that by changing resolutions and then changing back, it gets rid of the artifacts for a couple of days. Basically the same as a restart does but much faster way to get rid of the problem temporarily.

Hello here,

the phenomenom just happened to my computer (iMac i7 last revision). The menus are blured, as are the icons on the command-tab screen, the dashboard or the icons in exposé (not the windows content, just the application icon on top of them). The rest is perfect (photos, videos, background etc.). I tried changing resolutions as proposed by escobar929, but it did not fix the issue. Hope that tomorrow's MacOs update will fix that

I have an iMac that I bought in August

My info: iMac 3.4 Intel Core 7, 16GB Ram, AMD Radeon HD 6970M 2048 MB

I have also an SSD drive, so the computer doesn't have to make some noise, but I can definitly hear the fan of the videocard.

Sometime, everything works fine for while, and after I'm starting to have some screens problems like the one attached or blury icons or the image get stuck.

The problem seems to be there from the first time that I got the iMac, but It became anoying so I started to look on the net, and seen that I was not the only one with the problem.

My next step is to call Apple Support.

So did 10.7.2 update fix this for anyone?

It doesn't happen very often to me (like 3 times in past couple months) so I cannot say for sure.

Hey, I think the 10.7.2 update fixed the problem. 🙂