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

Hello Warren,

I've figured out that the 4850 in the iMacs is the mobile one, because the normal just wouldn't fit in the case. I know you didn't ask about my video specifically, but I really forgot that the one I have is not the same as the one in the iMacs.
You can get a better picture now, and imagine if the default 4850 gets hot that much, what's left for the mobile one, which has a lower clocking, but still hot as we can see.
I totally agree that the nVidia GPUs are way much better than ATIs, and not only for gaming tasks. Overall I think nVidia have the better graphic cards, for everything and they're the leader.
As you've mentioned in one of your newer posts, that a familiy member of yours has bought a 24 inch iMac, I'm really thinking of doing so, incase there's no expected solution soon.

I hope your unit arrives in a good condition and doesn't have any problems in the future !

OK Guys - my new (48) is here!

Initial findings:

Casing - perfect
Glass - perfect
Screen - perfect

I decided to reinstall the OS rather than rely on the factory before migrating over my existing clone. Once the OS was installed I booted up from my clone to run various diagnostics and a screen pixel check. Ran DiskWarrior and repaired the main HD (including 1 critical volume issue that was found. Seems like they all come like this as the previous one had it too). No flickering (doesn't mean much at the moment though). Just finishing the migration after which I'll repair the HD directory one more time, repair permissions and then give it a good testing. I'll report back later.

Thank Warren Been through that years ago too but with servers and Plasma screens that just pop and died. Most do not see what happen to line voltage when compressors and fusers activate. Just though I would throw it out there.

Simon (UK) wrote:
Ran DiskWarrior and repaired the main HD (including 1 critical volume issue that was found. Seems like they all come like this as the previous one had it too). No flickering (doesn't mean much at the moment though). Just finishing the migration after which I'll repair the HD directory one more time, repair permissions and then give it a good testing. I'll report back later.

Hello Simon,

Thanks for the update. It's helpful.

A few questions...

It sounds like you are saying that you did a clean install of Snow Leopard on your new machine, and then you ran DiskWarrior on your new machine after the clean installation had completed.

You then state that there was one critical volume issue, and that you think that all of the new iMacs may come with it, being as the previous defective iMac had it as well.

I'm a bit confused here. If you did a clean install, how do you not know that the volume issue was a result of the re-install? Or are you saying that you ran DiskWarrior before you did the clean install?

Also, what was the precise volume error that was repeated on both machines? It might be helpful for us to know what it was, so that we too can keep an eye out for it.

I also have a migration question for you.

While I have been thinking of also migrating from my current G4 once my iMac arrives, I do have some reservations about doing so. This is because I have read here on the Apple site that Apple does not recommend that these new iMacs running Snow Leopard should be booted from a machine, or external drive, that is running an old version of the OS.

In my case, while I would not be booting my new iMac from an older OS, my G4 is currently running on Tiger 10.4.11. I am concerned -- based on what Apple has stated -- that migrating my Home folder from my Tiger machine to my Snow Leopard machine might not be such a smart idea. These new machines are having enough problems on their own without me creating a new one.

Also, if I do use the Migration Assistant to migrate from my G4 Tiger machine to the new iMac, it will simply ignore the older Tiger versions of the default Apple programs, and just copy over my personal programs, correct?

Anyway, what do you -- and everyone here -- think about this?

Having to re-install all of my personal programs will take the better part of an afternoon, and I'd really like to avoid that; but if a Tiger to Snow Leopard migration is not advisable, then I won't do it.

Thanks folks!

GSears wrote:
You can also do a test by just making your desktop white or light gray. The bars seems to just make it more obvious and helpful. If you don't see the yellow on your screen - maybe you don't try the gray bar test... as it might make it more obvious to you. It's sort of the whole "ignorance is bliss" kind of deal. Up to you.

Hello again GSears,

If anything, using that gray bar test -- or setting the desktop to white -- confirms the stability and durability of these older CRT monitors.

As you can tell from my signature block below, until my new i7 iMac arrives, I am stuck with using a 733 MHz G4 Mini-Tower with a 17" Apple Studio Display. This is the display that is powered directly from the CPU. It was built circa 1999 I believe, and was one of the earliest G4's. I bought two of these G4's in early 2000.

Well, actually, the display is from circa 1999, but the G4 I am now using is actually from 2000 or 2001. My original 500 MHz DP G4 from late 1999 just kicked the bucket recently, so I am now using its Studio Display with the 733 MHz G4. The 733 MHz G4 has a ATY,Rage128Pro graphics card. Oh, and did I mention that it only has 16 MB of VRAM?

Other than being a little too slow to watch most movies and such, this old machine pretty much still meets my basic needs -- writing, web design, web surfing, email, etc.

I did both forms of the yellow tinge test, and this 17" CRT Studio Display is a uniform white from top to bottom, and there is no flicker, and only one dead pixel after all of these years.

It sure would be nice if these newer, snazzier LCD monitors were just as durable and reliable as these older CRT's. As I've said before, the idea that my new iMac may only last 5 years is something which I still find hard to swallow.

Message was edited by: Warren Beasley

Warren Beasley wrote:

I'm a bit confused here. If you did a clean install, how do you not know that the volume issue was a result of the re-install? Or are you saying that you ran DiskWarrior before you did the clean install?

I ran DW after the installation. It seems it may be an issue regarding the installation of SL itself.

Also, what was the precise volume error that was repeated on both machines? It might be helpful for us to know what it was, so that we too can keep an eye out for it.

Sorry no other info - it was just a critical issue.

While I have been thinking of also migrating from my current G4 once my iMac arrives, I do have some reservations about doing so. This is because I have read here on the Apple site that Apple does not recommend that these new iMacs running Snow Leopard should be booted from a machine, or external drive, that is running an old version of the OS.

In my case, while I would not be booting my new iMac from an older OS, my G4 is currently running on Tiger 10.4.11. I am concerned -- based on what Apple has stated -- that migrating my Home folder from my Tiger machine to my Snow Leopard machine might not be such a smart idea. These new machines are having enough problems on their own without me creating a new one.

It's not a problem. You won't be affecting the system when you migrate. This is specifically designed to do just what you're wanting it to do. So don't worry.

Also, if I do use the Migration Assistant to migrate from my G4 Tiger machine to the new iMac, it will simply ignore the older Tiger versions of the default Apple programs, and just copy over my personal programs, correct?

Correct.

Hi Simon,

Glad to hear you received your new week 48 i7. I am also eagerly awaiting my replacement to be shipped. I initiated my return on 11/21 and I'm still stuck on "not yet shipped". I was curious when you initiated your return and how long it took for it to come in.

Hello,

I am planning to buy this iMac too. After I read this topic though I'll be waiting for the problems to be fixed.

I was wondering though, could the flicker be caused by a cell phone which is near the imac? Because of the frequent data sending by the phone may interfere with some of the hardware in the mac. And almost everyone has a cell phone. (hence the frequent reports)

Maybe someone can test by using 3G near the imac or something?
Just a thought.

Message was edited by: Wiley-vs-Acme

So some of the machines don't act up once they are sitting in front of an Apple tech, and running Apple's very own diagnostic tool reveals absolutely nothing.

Makes me think of mains power quality.

I wonder about power supply. Pretty good here and for now I am NOT running i7 on ups. My older Intel has not released ups yet! My i7 is impressive so far. Reading these threads makes me nervous.

While I have been thinking of also migrating from my current G4 once my iMac arrives, I do have some reservations about doing so.

I would have more than reservations. I would NOT do that. I cannot recall details but more than two years ago I ran Migration Assistant from a G5 iMac to the 24" Intel iMac still here. A mess resulted. As far as I can see, MA has improved and after some thought whilst my i7 was in transit, I opted to use MA from the 24" to the i7. It worked fairly well with a few wrinkles. I now suspect that wrinkles might have come from the source. Only today I got around to finding issues via Disk Warrior - which I had not run since Snow Leopard release - on the 24" Intel. Running DW on the i7 found similar things. Hence my suspicion that I transferred unclean things.

I repeat, I would not use MA from G4.

Edit: I see I am at odds with Simon here. Now it could be that MA in SL is much better today at rejecting unsuitable things but I would not chance it.

Message was edited by: ScotMij

Hello Scot,

Well, the more I think about it, and the more I read the messages in these forums, the more I am leaning towards re-initializing and partitioning the 2 TB hard drive -- in order to separate the OS -- and doing a clean install of SL when the i7 iMac finally arrives.

After that, I will run Software Update until there is nothing left to download, followed by repairing permissions and running a disk utility to defrag and optimize the boot partition.

After that, I will do virgin installs of all of my personal programs -- which will mean re-registering everything again. It will take a lot longer, but given all of these reported problems, I think that I feel safer about taking the long route, instead of using Migration Assistant this time around.

Besides, there may be files in my Home folder that I no longer want or need. In fact, I know that there are a few Classic programs I currently run under Tiger on this G4 which won't be able to run under SL anyway -- like the Public Address BBS software, the Hermes BBS software, and a few other oldies I still use.

BTW, it's been 18 days since I finalized my original order; so to those of you who are grumbling about waiting so long for your replacement units, think of us poor folks who are still waiting for our original orders, and don't have a clue regarding how they are going to arrive.

Is it just me or has Bluebermuda went away?

He never did answer my points that I made...........

starocker wrote:
Mine is W8948, now flickering...

I've been following this thread pretty closely... I think you may be the first "48" to report this problem. Sorry to hear about your flicker. How long have you had it?

blue did go away (from this thread). Now why would you invite him back like that!! You should delete your post!!