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

O.K. I have had my 27 i7 for 30 hours, have had it on the entire time W4950... all is well.

{quote:title=Sonics99 wrote:}Mine has done it while actively using it and not just when it is attempting to sleep which is why I say it is not conclusive. {quote}

Mine too. The Apple guys kept asking me if my system was going to sleep, whether I was sure I hadn't let it sit for a while, etc., and I had to emphasize that no, I was actively typing and in the middle of a sentence the last time it happened, so if it was going to sleep, something would have to be wrong with it that would cause this.

That's great - many thanks Sooners.

I'll report back with what Apple UK say on the phone (and any email reply they give me).

Paul S. wrote:
The 27" 3.06 shows 2 weeks but with the extended keyboard it shows ships in 24 hours. It doesn't look like they have stopped all 27" shipments.

I bet those are already built units. Only way it would ship within 24 hours.

Has anyone tried safe mode, it might isolate some of the possible combination of software conflicts. Unfortunately it wouldn't rule out buggy firmware if that was the cause. Also booting from the install dvd would produce the same effect.

I present the information below, not that I expect any of you to tear apart your machines like I have and attempt these steps, but simply to give us an understanding of things we can test that if we can solidify might help us narrow the problem down. Less relevant to those of us that just want to play the exchange game, but for me I am really interested in finding out what is going on and if Apple won't tell us then I suppose I have to figure it out on my own.

Starting Up in Safe Mode
A Safe Boot is a special way to start Mac OS X when troubleshooting. To start up in Safe Mode:
Make sure computer is shut down.
1. Press power button.
2. Immediately after you hear the startup tone, press and hold Shift key.
3. Note: The Shift key should be held as soon as possible after startup tone but not before.
4. Release Shift key when you see the screen with the gray Apple and progress indicator (looks like a spinning gear). During startup, ”Safe Boot” appears on the Mac OS X startup screen.
5. To leave Safe Mode, restart computer normally, without holding down any keys during startup.


Here is the information given for suggested steps with regards to flickering issues:

Apple suggests in their support documents-
1. Verify if it occurs with an external display too. If it does (see separate chart)
2. Check all four cables for being damaged, pinched, etc...
3. If it still occurs shine bright (low heat) flashlight into front of LCD. Verify if an image is being displayed when flickering issue is occurring.
If so, replace vertical sync cable (between LCD panel and upper end of LED backlight board) and retest.
If issue persists, replace LED backlight board.

If not, replace internal DisplayPort cable (between logic board and LCD panel), and retest.

For horizontal lines it says:
1. boot from dvd and see if it still does it, if not, it is a software issue
2. if it does still do it, check external display, if it does it there it is not the lcd, but could be the video card.
3. If video card is replaced and reseated and it still happens
4. Check ram by using only one module and testing with another available module.
5. If it still happens replace logic board.

That is about it with those two issues.

I have the diagnostic LED codes and trickle voltage readings and pinouts as well, so depending on how much time I get tomorrow I am going to see how all of those match up too.

I've been watching this thread for almost as long as its been running. I have been waiting eagerly for any news of a fix before I purchase my new i7. I just wanted to finally add my two cents. My hope is simply to contribute to the size of the discussion so that hopefully Apple will give some sort of communication to boost consumer confidence in this product. I find it hard to believe that after all this time they haven't isolated the problem. They should let people know whats going on, even if its through back channels. I'm sure that there are many others like me who are waiting to purchase systems as soon as this problem has been resolved.

I too have read and followed every post on this thread. At the time that it was started I was still saving up for a fully loaded i7, and was reading all that I could find in anticipation of finally being able to order it. However, since that time, well over a month, I've been able to save up just about $3k, so I could order one any day, HOWEVER, there's no way I will order one now until Apple announces they have found and fixed the problem.

I've had my new iMac for a week now and so far I haven't had ANY issues. **knock on wood** So far everything is working perfectly.

my flickering is happening more often after a startup than a wakeup but after a wakeup it takes 10-14 seconds to recognise the ethernet cable and connect, in which time i can have a beachball. not sure whats going on in that time or if its related but talk of sleep/power issues made it sound familiar.

I have mine allmost a month (3rd replacement) and it has no problems. it is week 47. Strange thing was... when i called apple for the 3rd time and complained about this problem they've said "this one will be ok, 100% sure"...and it is indeed ok.

Strange

Gille_Belgium wrote:

I have mine allmost a month (3rd replacement) and it has no problems. it is week 47. Strange thing was... when i called apple for the 3rd time and complained about this problem they've said "this one will be ok, 100% sure"...and it is indeed ok. Strange.

Strange indeed. Although, considering some people have later built models that show symptoms, I'm thinking that was merely 'Customer Service speak' to make you feel good after having had 2 failures. Remember, not every single iMac sold has these issues. For me, I'm almost at the 2 week mark with my replacement 48 week unit and no issues to report.

Here I sit on day 24 of my new iMac 27" and so far (knock on lots of wood) my week 41 computer is not showing any of the issues the others seem to be having. I just feel that I am sitting on a time bomb and where I had my iMac G4 for seven years without issues I am not so sure that this computer will last that long.

Just wanted to report where I am or where I think I am going. Thanks for taking the time to read this.

Message was edited by: old john

Simon, reading this forum and when i look at my own experience, i had the feeling that 80% of all imacs went bad It's not an isolated case , but i think that probably 15%-20% are faulty. This is my personal guess.

Same here!, waiting to hear a clear resolution to buy. I've been using PCs and Macs for more than 15 years. During the last years I've been using PC with windows XP and to be honest it has worked perfectly. However, I can't stand windows and it's about time I changed it for a Mac again. Good luck to everyone and thanks for keeping people like me informed about this issues.

Geez, they're so polite at Apple Support it is hard to be mad with them(!)

I rang them and got transferred through to their support department. I was told the replacement would not be shipped until after Xmas. I pointed out that I did not want to return my flickering iMac until the new one had arrived and the guy said this would not be a problem.

I have been told to expect an email confirming all this in the next 48 hours.