2009 Early iMac Freezing 3.06GHz,24", ATI 4850

CNET and the like have not picked up on this possibly for the same reason the AppleInsider blog disappeared in talking about the immenent release of 10.5.7 and how it was available internally to employees already......Apple has long arms with big muscles.

Hi there,

I just found an interesting post in the forum of MacRumors.com...

"Ok to catch you up to date. I emailed Tim Cook, the acting CEO of Apple while Steve Jobs is taking some time off. I got a phone call from his team. They had a High Level Tech Support Specialist contact me today and they gave me a program to capture my logs to trace why my freezes have been happening. They are putting a High Priority on it and I should know something within 24-48 hours. I will relay the findings here.

+I did ask her a few questions regarding fan control, I see on this site that some of you are installing smc and other software and making your fans go faster to cool down the temperatures. She told me that it is not recommended that you do this, and that is because it will make your fan not last as long as it should for one thing.+ That alone is good enough for me. I did install istat to monitor some readings. She said that is ok, but they are not 100% accurate. But they will give you some idea of what is going on.

(...)

According to this Tech Support Specialist, the Apple Engineers do not have enough data yet and needs to collect as much as they can to figure out the program. So from that I think this will not be a quick fix. We are probably looking at least a month at the earliest to see a fix on this and maybe longer."

( http://forums.macrumors.com/showpost.php?p=7546265&postcount=410)

Partyschaum wrote:

I just found an interesting post in the forum of MacRumors.com...

(...)

+I did ask her a few questions regarding fan control, I see on this site that some of you are installing smc and other software and making your fans go faster to cool down the temperatures. She told me that it is not recommended that you do this, and that is because it will make your fan not last as long as it should for one thing.+ That alone is good enough for me. I did install istat to monitor some readings. She said that is ok, but they are not 100% accurate. But they will give you some idea of what is going on.

I know this is you quoting someone else quoting a tech rep, but I think this person is out to lunch. By kicking my fans up just a couple hundred RPM, I was able to drop the northbridge temp from ~80°C to ~60°C and the power supply temp from ~70° to ~50°. That's a huge improvement, and there's no noticeable noise from the small bump in fan speed.

In addition to fan life, dust is also a concern, but I say excessive heat trumps them both. I just wish this Intel iMac was as easy to crack open and blow the dust out of as my G5 iMac was. Now if you'll excuse me, I've gotta go buy suction cups and torx bits...

I recieved my replacement IMAC on Monday (for my previously freezing one the week before)and had about 2 hours use out of it prior to it freezing again. Usual suspects that cause a hang are Migration assistant, Streaming movies etc. I called Apple who were very good and didnt even try to mess around with basic PD admitting that they had been aware of these issues being logged for 2 weeks. They referred me immediately to technical support who sent me a diags prog to run and send them the output. Next day I took a call from tech support to tell me that its a known issue and the workaround is to disable wireless card whilst apple work on a fix but no eta at this point. I asked if they could guarentee to me in writing that this wasnt a hardware issue and that it would be fixed by firmware or driver and was told that they couldnt (apple confidential). As such ive sadly sent back my machine for a refund. Great machine if it had worked but im not prepared to lose warrenty period on a failing machine whilst Apple look for a resolution. I have to say I feel this should have been easily uncovered in product testing. Tech support were as open and honest as they could be which im appreciative for and they were very responsive. I was asked if I wanted the NVida model but Id rather wait to get the product I wanted in the first instance (Which may still be Apple in the future). Good luck all. Hope this info helps those in their 14 days to make a suitable decision.

I also received a faulty imac with the same freezing symptoms, I have noticed since I've connected via Ethernet the freezing has stopped. Whereas before I would have about 1 to 3 freezes per day. But the other day I thought I'd connect via Airport just to test if it was really causing the problems and too my suprize the iMac froze again when connected to Airport.

Anyways my replacement is on its way.

Apple does not have a great history of acknowledging thee issue or fixing them quickly but they do fix them. Hopefully there will be a fix in 10.5.7. I had an iMac with the last ATI card problem and it was really irritating until they finally fixed it.

It would be interesting to see if the latest models with the 4850 have this issue. That would be data worth collecting.

I had it on a fresh install of Vista (after Boot Camp drivers installed) until I ran windows update and got it completely up-to-date. I think it was cleared before I ever installed Sp2 too. But it's had no problems since being completely up-to-date. I haven't launched windows lately but OS X has definitely frozen a couple times in the past few days. Never anything really correlates with the feeze.

Another quick update. Replacement unit continues to freeze. The last freeze, I was handed the Black Screen. Looks like the sure signs of overheating to me.

Be patient, a fix is imminent. If you can use ethernet instead of WiFi, that is the current work around. This will be fixed very soon, no need to return your iMac.

Jim, I hope you're right. Being patient so far. Not using wifi seems to be working so far. It'll do but it's not going to be an acceptable fix, long term.

Do a software update - firmware available.

It's a done deal: firmware update. Just posted.

"This update fixes intermittent system freeze issues for iMac computers with ATI Radeon HD 4850 graphics and fixes wake-from-sleep issues in Boot Camp."

Do software update or go to http://support.apple.com/downloads/iMac_EFI_Firmware_Update_14

That really didn't take very long. Thank you Apple.

Coolness. Now i can finally buy one!

Hey Jim, how is that 8GB working out in your iMac? How much does it use during normal operations?