iMac 24" Early 2009 Freeze

[Skorpion24]

Hi guys, from yesterday my iMac started to have an annoying problem, If I put him in Stop•Sleep, when I push a button to wake him up, he won't start, the fan starts but the screen is black and its like blocked.

Same thing if I turn off the screen, but he's running, after some time if I push a button or move the mouse to turn on the screen, he's freezed, blocked, the fun are running but the screen remain black.

Then today, he block himself during while I was posting on a forum, so when he was on.

I checked the HD and other stuff with Onyx and everything looks fine.

One month ago I updated to 8GB of ram from Crucial, don't know if this could be the problem, but until yesterday I had no problem and no Kernel Panic at all.

Now I tried to remove the kit and put the default base 4GB kit.

 

[Skorpion24]

Anyone?

 

[Spike88]

Suggest pulling out the added memory. Bring it down to factory memory (4 Megs ???). Then, try it for a few days. If NO more freezing events, you found the problem. re: Defective "extra" memory simms.

Also... R U running SL or Lion? Sometimes, Lion creates strange behavior as well...

 

[SaSaSushi]

In addition, you might try reinstalling the new RAM and running Rember to see what results you get.

 

[Skorpion24]

Ok guys now I'm using the "old" 4GB kit, and looks ok, no freezes or problem at all, the mac wake up always from sleep and works like always did.

Now we can assume that the problem is the Crucial 8GB Kit, but the strange thing is that if it was faulty I should have this problems immediately not after a month, am I wrong?

BTW I'm under Lion, clean installed, not upgraded.

 

[rkaufmann87]

Ok guys now I'm using the "old" 4GB kit, and looks ok, no freezes or problem at all, the mac wake up always from sleep and works like always did.

Now we can assume that the problem is the Crucial 8GB Kit, but the strange thing is that if it was faulty I should have this problems immediately not after a month, am I wrong?

BTW I'm under Lion, clean installed, not upgraded.

Nope, RAM like anything else can fail at any time. You can't assume that because it was fine one day it will be fine the next.

 

[Skorpion24]

I see, as soon as I do the tests I'll post the results with 4GB default kit and 8GB Crucial one

 

[Skorpion24]

Ok now I'm confused, here's the thing.

Did a test with the 4GB base kit and everything was ok.

Then I decided to run the test after a reboot, and here the results

Then I installed the 8GB Crucial kit and after like 1h 30m here's the results

 

[Spike88]

Remove the Apple "factory" memory and replace with your 3rd party memory. Reboot and run test again.

If clean, you know the problem is with Apple memory. re: The memory you removed for this test.

And yes, memory can be "unstable". Meaning it works sometimes and when the internals get hot, it stops working properly. Broken memory doesn't always mean an on or off "broken" condition.

.

 

[Skorpion24]

Just to be clear, when I got the freeze problems I had the 8GB kit.

After that, I used the base 4GB kit for some days to see and I had no problems, today I tested it during a normal session and the test was ok, then I rebooted and he failed.

Then I installed the 8GB kit and did the test with positive results.

I think I'll keep the Crucial kit and see if the problem come back, what you say?

 

[Spike88]

Just to be clear, when I got the freeze problems I had the 8GB kit.

After that, I used the base 4GB kit for some days to see and I had no problems, today I tested it during a normal session and the test was ok, then I rebooted and he failed.

Then I installed the 8GB kit and did the test with positive results.

I think I'll keep the Crucial kit and see if the problem come back, what you say?

Chasing down a memory or other circuit problem is a pain at times. Pass one test but soon after, the exact same test fails. It's like a ghost floating around and around the system. No clear reason...

As another check, download iStats Nano (which is a free widget program) and monitor its internal HEAT temps as well. Wonder if "the ghost" appears with CPU is above xx temp number? Wonder if "the ghost" appears with HDD is above xx temp number? Might be an internal heat pattern thing as well.

.

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Lion + Freezing..... MMMM.....

Related to: https://forums.macrumors.com/threads/1238402/

Could be same problem as your iMac (????).

.

 

[Skorpion24]

Thanks Spike I appreciate your help.

I do not use iLife suite so I don't think that's my case.

About temps, yeah I've istat installed of course, and this summer I opened a thread on this because I was worried about the high temps, but I think that was because of the very high temperature and humidity we've got in Italy.

Anyway these are my actual temps