Q: New iMac 27inch screen flickering/tearing/shutoff

My week 50 27" i5 iMac arrived on December 14 with 8GB RAM - and for the past 12 days it has been on 24/7 - running a slide show from Photoshop CS4.

I have never seen a flicker or a blackout. I did install the new firmware, even though I had no problems to fix.

I remain cautiously optimistic at this point - and I am glad that I have Apple Care for the iMac.

I wonder what percentage of new 27" iMacs have -like mine - zero problems?

Happy 2010 to everyone.

thanks for that!

basically apple still have no idea then??!

i wonder how they'd go about trying to resolve something as widespread as this? where would you even begin???

I would hate to see this thread turn into a complete rant and get locked. Keeping it specific can benefit us all. Let's face it, Macs are the best even when we hate them. My first Mac was a G5 dual 2 and froze at every turn. I loved the machine, but hated it too. After weeks and weeks of negotiations I got a new machine and it was totally flawless for five years then the motherboard went. Then I got my I7.

My 50 week build I7 which came with the update has been flawless except yesterday the banding started with two brief blackouts. Not a happy camper, but turned the machine off and unplugged everything, pushed the start button for twenty seconds, reconnected wires and turned back on. No more issues so far but time will tell.

Only the very slightest hint of yellow on the bottom of the screen. Not enough for me to worry about. My I7 is so amazing. It's super quiet except when the HD is reading, then a low level rumble can be heard but this is imho to be expected. You should have heard my G5

Good luck to everyone here.

I have a week 49 27" i7, 8g ram, 1TB HD, and have had minor flickering and black outs. Not enough to really concern me. After I down loaded the Firmware up date I had the banding appear once. That prompted me to call Apple and document this problem on my machine. Since I called last Tuesday I have had no issues. I called from work (iMac is at home) so all they did was make an appointment for me with the nearest Apple store, which happens tomorrow. They tech I talked to said the only thing he would have had me do was unplug everything and let it sit for 15-20 muntes any how.
Unless the Apple store can tell me what the cause of the problem is tomorrow, they will not be exchanging or sending my current iMac anywere. All I want is to have this issue on file with Apple incase it worstens or the next year I have coverage. I have no yellowing of the screen and I am over joyed with the quality of the picture. Editing photos and videos is amazing on this iMac. The detail you can see blows me away!

I just got a 27 inch quad core iMac with the aformentioned flickering and blackouts. I'm very certain it is a hardware issue. I have my macbook pro screen sharing with the iMac and none of the flickering or blackouts occur on the macbook pro. I have also tried getting a screen shot of the flickering or blackouts with no success. This leads me to believe that it is an issue with the lcd screen. If it were a software issue it would show up when screen sharing. If it were a graphics card issue I could have gotten a screen shot of the flickering or blackouts. Therefore the only thing left is the lcd screen. I'm not telling anyone to go out and buy a replacement screen. I'm just expressing my thoughts.

Thats pretty interesting.. in fact thats the most helpful thing ive seen posted (not saying everyone else isnt helpful) but it narrows this crap down a little better... they need to recall!!!!! I have yet to see the flicker since i did the update about a week ago but im waiting as soon as I see it im returning the beast and waiting till march to get another one... ***** because I blew my whole savings account on it and its the nicest computer ive ever had

chonody wrote:
I just got a 27 inch quad core iMac with the aformentioned flickering and blackouts. I'm very certain it is a hardware issue. I have my macbook pro screen sharing with the iMac and none of the flickering or blackouts occur on the macbook pro. I have also tried getting a screen shot of the flickering or blackouts with no success. This leads me to believe that it is an issue with the lcd screen. If it were a software issue it would show up when screen sharing. If it were a graphics card issue I could have gotten a screen shot of the flickering or blackouts. Therefore the only thing left is the lcd screen. I'm not telling anyone to go out and buy a replacement screen. I'm just expressing my thoughts.

To be honest I do not think that this proves it to be a non-GPU issue. It might be that Mac OS X generates screenshots by rendering it in the software and not by taking the buffer in the graphics card. This would explain for example why the window in the Grab.app does not show up in a screen shot. Maybe I am completely wrong though, who knows...

What you could try to do is also take a movie of the screen with the quicktime player and see if it shows up there. It might just be that you were a little late while taking the screen shot

I'll try that right now!

@suba and others

People of whom the hd rumbles, is it possible to make an audio recording of it? I would like to compare it with mine! But the noise of my hd also shows up whenever I am NOT doing anything. I wouldn't be lying if I told you that I hear it every 3-4 seconds.

I spoke with an employee of my local Apple Store today and he quietly admitted to the flickering problem on 2 out of the 3 display 27 inch iMacs (which they promptly moved off the showroom floor) and that his own, personal iMac suffers the malady without relief from the firmware update. The positive news gained from my conversation is that he remained relaxed that Apple would prove reputable in solving the problem and had no inclination to send his faulty unit back to the company. He stated his only hope was that the issue would be solved via update, and not via dragging the heavy computer back to the store.

He also stated, positively, that he has not witnessed one computer sold from the store returned for repair or replacement, adding that the 27 inch iMac has been a huge selling success. I'm hoping this implies that the problem, albeit widespread, remains a small percentage of the units sold. (mine will be delivered 12/29... gulp, gulp.)

chonody wrote:
I'm very certain it is a hardware issue. I have my macbook pro screen sharing with the iMac and none of the flickering or blackouts occur on the macbook pro. I have also tried getting a screen shot of the flickering or blackouts with no success. This leads me to believe that it is an issue with the lcd screen. If it were a software issue it would show up when screen sharing. If it were a graphics card issue I could have gotten a screen shot of the flickering or blackouts. Therefore the only thing left is the lcd screen.

This has become a massive thread so it would be unreasonable to expect you to read it from the beginning. But I have read this thread from the beginning, and can say you have not brought any new information that hasn't already been discussed many times over. You maybe on the right track, but I'm placing my bet on those who suggest that something is dodgy with the power supply or isolation of the power supply. On your next coffee break read the following thread about an issue with the 24 inch Cinema displays...

http://discussions.apple.com/thread.jspa?messageID=10786900#10786900

There are some interesting similarities.

Ed, mine sounds like a very faint sound that you would hear from an aquarium. Just a little burble even when I am doing nothing. The sound seems to be coming from just below the apple logo on the back but it's hard to tell. I think this must be normal, but here's a little story.

I originally ordered an i5, but discovered the noise and boy was it annoying. I called apple and after some time they told me to take it to my reseller. I took it in and explained the problem, but decided to order an I7. My i7 is very quiet. I can't believe some posters are saying they have no sound whatsoever coming from their macs. I'm in a very quiet room as well. btw, both the i5 and i7 were 1 TB Seagate. I have also not seen any more banding on my screen . The temp in my room was rather low, and I'm wondering if the banding might be caused by low temperature ( probably not but who knows ) It would be interesting to see what geographic area people who have this issue live. I live in northern Ohio. I remember that people were complaining with the old G5's because they would boot to a black screen in the morning, but it was discovered that many computers were in cold rooms at start up ( winter ) and keeping the temp up a little seemed to solve that issue if I remember right.

If you feel your computer is simply acting unusual, contact Apple and get it on record. If you are hearing a very faint burble even when doing nothing imho there is nothing wrong. btw, my reseller checked my i5 and said it was within specs and sold it to someone else. They said they could not detect anything abnormal, but my i7 is much quieter and glad I have it.

I just noticed my first blackout and flicker since the update. I have noted, all along (update did not seem to affect this) that while in screensaver with an iPhoto folder, I get stuttering and freezing on a single frame, and a kind of flashing as well. This is especially so if I am using the mosaic program.

So. I guess I'll be calling Apple support to at least register the problem and protect myself. I am not inclined to replace or repair the hardware until I feel confident that there is a real and known fix out there. The problem now does not interfere with my use much, and seems to be fixed temporarily with the rapid sleep/awake trick.

I just turned our new 27" i5 machine on yesterday (it was a Santa gift to the family) and just started seeing the flickering and vertical shift today. I've got the firmware update - actually installed it yesterday during initial S/W update check. I tried the sleep/wake cycle and it seems to have temporarily resolved the issue, but I expect it to return. Will log the issue with Apple Monday to get it on record. Can anyone tell me where I get the "Wxxx" number I see mentioned in these posts? Would like to know if I've got a unit that was in a corner somewhere - I THOUGHT I had it "custom built" to my order, but that may be the hype behind a week-long delivery delay.

In the meanwhile, I'm REALLY enjoying the beautiful display and blazing performance, when it ISN'T flickering!



Marsh

SwampD.........."Can anyone tell me where I get the "Wxxx" number I see mentioned in these posts"

Click on the Apple in the upper left corner of your screen

Select "About this Mac"

In the window that launches, click on "More info"

In the window that opens, look under "Hardware", and the next to the last entry will be your serial number. The third and fourth numeric entries will tell you the week your unit was built.

Or

You could turn the unit upside down, I believe they still put the serial # on the bottom of the base.