Imac display issues following Yosemite upgrade

Thanks for the tip. I did the same and looks like the issue is gone. I will report later if the issue comes back but for now after 24h my iMac is working totally fine for the first time after Yosemite upgrade.

Hi guys,

In my case transparency is the trigger. As soon I turn ON transparency in my mid 2011 27" iMac the display issue is back. It takes no more than 2 min to get the display issue after turning transparency ON. Then if I turn it OFF the issue is gone. This is a definitely a Yosemite software glitch!!!

To turn Transparency OFF go to: System Preferences / Accessibility / Display / Reduce Transparency

I firmly believe it's cold solder joints. Since I fixed a drafty window and maintained room temperature in my office the graphical issue has been gone for over 2 weeks now. It's funny cause I always thought computers worked better cold from my overclocking days. I don't think this is the case anymore with lead-free electronics.

Give it a shot. Just make sure your computer is in a warm place. OS X updates come out in the fall when it dips down to zero temperatures at night in some climates. Updating heats up your GPU specially with all the new graphical enhancements. I think during the update combined with the cold weather the solder expanded and shrank. I had this same issue last fall and had Apple changed my components twice. It happening again definitely confirmed it's an environmental problem.

Cold solder joints on lead-free solder. Remember these things are designed and tested in Cali.

I just sent a note about this issue to the team at AppleInsider (http://appleinsider.com/submit_story/) and encourage others to do the same. Maybe some press attention to this issue will earn a response of some kind from Apple. Otherwise we'll all be cooking our graphics cards alongside our Thanksgiving turkeys.

spantspants - I sent a note to AppleInsider, we can only hope that if enough people do, someone will notice.

Billy,

I iam not sure if it's cold solder joins. I think one person mentioned it worked fine after restart, or it started again after the computer restarts.

If it's cold solder joins it will keep happening, well usually..

I have the same issue as jwjwj mentioned on 19, 2014 8:19 AM as shown in the picture. But currently it's not shown. Let's see how it is progressing.

Like I mentioned before my iMac has been free of display issues for the last 48H after turning OFF transparency. In my case transparency is the trigger. As soon I turn transparency ON the display issue comes back.

I wish I could say it was a magic bullet, enricoclaudio. Turning off the transparency has definitely helped, but I'm still continuing to have graphic issues (odd colored menus, buttons, type, etc.). It is more pronounced when it's cold, and when the machine has been asleep for a period of time or over night. Once the machine warms up and during use, it goes away.

jay,

same here. I got the issue when my computer came back from sleep, right after I attached my iPad.

After restart I haven't seen the issue.

Jay;

I, too, had increasing problems of late as ambient office temps decline, but haven't had a return of the "dancing pixies" since applying the change to the transparency factor... in concert with my earlier "success" of turning off all energy saving settings.

Ultimately, I've resigned myself to the inevitable necessity of baking my board, but I'm loathe to dismantle my entire machine until there's literally no alternative...

Enricoclaudio, your solution worked fine for me. Thanks

Yosemite 10.10.1 update to address Wi-Fi ... and hopefully our pixel storms issues!

Quick update:

My 'quick fix' if it start's happening is to enable Airport Display and enable Apple TV and then disable it, make sure you enable 'Mirror iMac' so your display changes resolution. May be just changing resolutions would also work, I didn't try that... I only happens every couple of hours (since today).

I think the net effect is that the OS will (re)initialise the GPU and thus whatever stopped working correctly also get's re-initialised.

This basically also ensures that the issue is not a hardware fault, but a driver issue.

Been getting this issue on Macbook Air since Yosemite upgrade. Just happened again and instead of restart went into Sys Pref then Displays, clicked on Color option (didn't even change any settings) and problem disappeared...might have just been odd fluke.

Maybe someone else can try it when the prob occurs...

Def a bug would be my guess in that case, not a 'solder' issue

For my system, the transparency setting is the key for the display glitch. it is reproducable and by that, no hint for a hardware failure. I can live fine without having the glorious transparency effect.

Transparency and energy saver settings have been my salvation to far, but this morning I awoke to a frozen screen that mandated a manual restart... aftter which my system returned the "video problem" report.... but so far, NO PIXILATIONS!

Mebbe Apple will respond, if they receive enough of these error messages?