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

I live in Denmark and I have the iMac running without ground. I have experienced flicker and blackouts a couple of times over 7-8 days or so. I have been thinking that running without ground might be the issue, but I don't have any power outlets with ground, so...I can't really test it. Is anyone running with ground at all?

I am also going to go out on a limb here, and suggest that wetting your finger and sticking it in your ear may solve the problem.

A more sure way though, to eliminate the screen distortion and flickering, is to close your eyes and pretend it has gone away.

Nice, so you've posted 4,990 times in a little over a year with this kind of advice?

No, actually 99% of it was good useful advice, unlike the butt of my joke.

Pray tell how the entirely irrelevant manipulation of your power supply is supposed to fix a problem clearly of Apple's making.

Unless the objective was purely to make users blame themselves.

I had a MAC specialist observe my computer for a week and apparently not a flicker. I brought it home and immediately saw the flicker problem. I then updated the software and no flickering problem for 2 nights. Someone had suggested in a prior post that the driver updates corrected their problem.

Good update rmp09, which updates did you apply?
Software update? 10.6.2 ?

my i7 came with 10.6.2 and i did the software update which only updated itunes and i think on of the ilife apps. tons of flickering once it started about an hour after the machine was turned on so 10.6.2 certainly did cure anything for me.

rmp09, please expand a little.

You had a problem with flicker at your location?
you moved the machine to another location with no flicker problem?
you returned the machine to the original location and the problem returned?
you updated some software (which) and the problem disappeared?

Thanks

Ok, so before calling Apple Care I decided I was going to try everything that anyone had mentioned in this thread to make this iMac flicker, shift and black out again. And for the life of me a can't, how ironic...we don't wan't these machines to flicker but now I do. I have a Genius appointment tomorrow so I thought I'd try and get some video of the flickering as proof.

A little background info for anyone reading my posts for the first time: Last night my machine flickered and blacked out for the first time so I did a little reading and the first thing I did was reset the PRAM (3 times in a row), the SMC and run the diagnostic tool and everything seemed to be operational without any flicker issues. Tonight I tried to recreate the scenario plus load 'suspect' programs as well as the airport to try and get this machine to flicker. I decided to load Call of Duty 2 along with every app in the dock and let it run for about an hour and a half while I ate dinner. I was thinking if this is a GPU overheating issue or some other GPU related issue running the game with max settings for an hour and half surely should create the problem again. No such luck, I'm stumped as to what caused the issue the imac is hot to the touch and no issues. I haven't changed the power source either. The only difference is I had a small desk lamp plugged into the power bar at the time...hmm maybe I'll plug that back in now and see. I'll let you guys know if I turn anything up.

One unrelated thing I just noticed is that if the display brightness is turned up max you can hear a very high pitched sound, around 3 steps down it seems to be gone...and actually as I'm typing this it seems to come and go now I'm not too savvy when is comes to how electronics are built but this could all be linked to a power/ground issue as mentioned above.

Interesting that you noticed the noise!

There is actually a thread going on regarding this as well, see discussion topic with title "21.5'' iMac - Screen Noise".

I was all for ordering an i7, but I'll wait for another month or so until the dust settles. From bits and pieces in this thread and other forums (e.g. macrumors.com), may be Apple is aware of the issue and is fixing it either at the assembly line or somewhere ...

Thanks for the input Trice... I would really like to hear the answers from rmp09 about his issues....

This thread is way to big so i'm going to start a new one for a diagnostic approach to this "flicker" issue.

In the new thread I don't want to hear from people that don't own or operate a 27" iMac (unless they are chip experts or electricians)
We all agree that there is an issue. We don't know what but rather than me too, me too, apple, apple, let's use a diagnostic approach to figuring this thing out. It helps apple and it helps us.

In the interest of full disclosure, I do not work for Apple, I've never been paid anything by Apple, I may or may not have ever tested anything for Apple - pre release (NDA)

Let's explore the things that cause some early machines to work and others that obviously have serious issues.

The new thread will be called "Flicker 27 - Diagnostic approach"

I'll start it but guys. it's almost midnight here and I won't join in until tomorrow.

Well I can't seem to get this computer to flicker again, this problem obviously happens randomly or somehow I solved it with one of PRAM, SMC resets I preformed. None the less from what I read from previous posters experience is that this almost always seems to come back even days later. So I guess I'm bringing my iMac back tomorrow morning and keeping my fingers crossed a new machine will be ok and hopefully not worse. I've waited months to buy this computer and now this...not impressed. My G4 Powerbook has been running for 4.5 years straight out of the box with now issues whatsoever. Anyways I'll be back tomorrow, maybe we'll see some progress.

To determine if it is a driver issue in Os-x, why doesn’t someone with the problem install Windows in bootcamp and see if the problem also exists there.
If yes, then it is likely a hardware or firmware issue. If no, then it is software problem in Os-x.

I have not yet received my i7 iMac, but till this is sorted out I consider cancelling my order.

Taking up the power angle, I thought it worthwhile to point out that I had flickering on one powerboard, and then when I packed it up to send back and then un-packed it again I managed to use a different power board. I have not had any flickering since. This was also the same time I did an OS re-install and upgraded to 10.6.2 however.

I am returning my machine since everyone who thinks the problem has gone away seems to report back later that it has returned. In the meantime I have switched back to the original power board to see if the flickering returns. If it does, there might be some credence to the power issue.

Even if it does, I think this would only reinforce that there is a hardware issue. If the graphics card is that susceptible to power quality I think that points to a problem with the hardware.

I am hoping my next one won't have the problem, but if it does I am going to keep returning them until I get one that is OK. Unlike some others, I am not blaming Apple for making a mistake since their support in resolving the problem and providing a replacement at no charge is great.

Oh, and the machine is beautiful.

The French apple care service seems to say it is a hardware issue (LCD Screen), they've had a lot of returns...