iMac Video Card issues methinks ?

[haikuman]

My video card on my late 2009 iMac/ 3.06GHz Core 2 Duo/12GB Memory/ 10.6.8/Safari 5.1.10
has been acting strange for about 2 weeks now.

I am only guessing this is a video card issue . . .

After several hours of using the computer I have to do a hard shutdown
because the mosaic patterns on the screen do not allow me to do anything else
by the usual commands.

This is an example but not from my computer. On my computer the mosaic patterns cover the entire screen.



I am back at looking at Apple refurbs again. I have a friend in Maui heading this way
in mid May. It may be time to pull the trigger.

Rudie *(:>*

[Fred_Also]

Mine is a 27" mid-2010 iMac. Been doing this a few months. Started out as random pink squares about 1/8" squares.

I ended up taking it to the local Mac dealer. They are still looking at it. It was a refurb from the Apple store and after 1 extra year of AppleCare, that expired Dec. 2013.




Fred

[bruceko]

My 2011 17" Macbook pro is doing the same kinds of things but in 1" squares.
Known problem with the Macbook Pros but Apple won't acknowledge the problem. They just keep replacing mother boards that fail again.

[comphernation]

Your screenshots don't look quite like the ones I experienced, but I wonder if it's similar to a problem I had …

I was given 2006 an iMac 20" Core 2 Duo that has issues with its graphics card overheating. Things go wonky, sometimes to the point of hard freezes. Searching Google for '2006 imac 20" core 2 duo graphic heating issue' showed that it was quite a common problem for that series, and likely an eventual death sentence in the long term.

There seems little to be done short of replacing the motherboard, but I managed with software to crank up the fan speeds, keeping it cool enough under most circumstances.

smcFanControl: https://www.macupdate.com/app/mac/23049/smcfancontrol
Macs Fan Control: https://www.macupdate.com/app/mac/47386/...an-control

Either of those might be worth a try, and they're free. At least it might help to determine if overheating is the issue.

iStat Menus -- https://www.macupdate.com/app/mac/25230/istat-menus -- isn't free, but it will show you the current temperatures of your various fans, so may be worth running the demo for that info.

I hope your problems are more easily fixed, but either way, I hope this is of some help.

[WHiiP]

I have a problem with my late 2009 iMac where the screen is split horizontally about two inches from the top. The Menu Bar drops down two inches and the dock comes up to the top. Very weird.

I go to the apple menu and put it to Sleep and then wake it up and all is well.

[Speedy]

bruceko wrote:
My 2011 17" Macbook pro is doing the same kinds of things but in 1" squares.
Known problem with the Macbook Pros but Apple won't acknowledge the problem. They just keep replacing mother boards that fail again.

Which OS are you running? I suspect in Mavericks Apple cranked down the processor performance to cut back on heat issues in the MBP. I have two early 2011 MBPs, one a 15", the other a 17". I use both for Folding@home which will peg the processors. The 15" runs Mountain Lion, the 17" runs Mavericks. The 15" runs very hot, the 17" runs much cooler (both to the touch at the top center above the keyboard.)

[bruceko]

Speedy wrote:
[quote=bruceko]
My 2011 17" Macbook pro is doing the same kinds of things but in 1" squares.
Known problem with the Macbook Pros but Apple won't acknowledge the problem. They just keep replacing mother boards that fail again.

Which OS are you running? I suspect in Mavericks Apple cranked down the processor performance to cut back on heat issues in the MBP. I have two early 2011 MBPs, one a 15", the other a 17". I use both for Folding@home which will peg the processors. The 15" runs Mountain Lion, the 17" runs Mavericks. The 15" runs very hot, the 17" runs much cooler (both to the touch at the top center above the keyboard.)
10.8.5 No Mavericks for me. Sticking with the Cats. When it freezes it gives a loud 3 beeps repeated. Normally means a memory probably.Top temps for the processor are about 160
Do a search for 2011MacBook Pro freeze. On the Apple community there is a 150 page thread for the 17" alone
Here is a 295 page discussion on the 2011 discrete video card2011 Macbook Pro and discrete graphics card

[haikuman]

Here are my current values all comments regarding these values would be appreciated.

[comphernation]

haikuman,

I watch my temps in Fahrenheit, as I can more easily relate mentally. It's just what I'm accustomed to. Using your readings:

HD: 56C = 132.8F
CPU: 46C = 114.8F
Ambient: 32C = 89.6F
Optical Drive: 49C = 120.2F

At those temps, my 20-inch iMac would be freaking out. When my GPU die reaches high 90s (F) things begin to go flaky, usually just video glitches at first. When temps reach 110F and up, hard freezes can occur.

I'm attaching screenshots in Celsius and Fahrenheit, taken when my my 20" iMac is idling. At these temps the machine behaves properly. The best way I've found to keep the machine functional is to keep all fans going full-tilt all the time. It's annoying, but the computer cost me nothing and saved my bacon when I needed it. Over time, I imagine it will get worse, so I recently found a newer iMac to replace it.)

One other thing: I found the air vents beneath of the 20-incher to be pretty clogged with dust bunnies, so I vacuumed that out. Inside is undoubtedly packed with more. At some point I'll try open her up and clean what I can inside. I'm not eager to bust this thing open, but if I mess it up, at least I now it's not my main machine. ;-)

I have no idea what temperatures your particular machine finds acceptable, but I'd imagine a Google search similar to mine will lead you to that kind of info, as will perhaps bruceko's link, too. Meanwhile, if you can stand the noise, you might try maxing all your fans just to see if the problem goes away.

20" iMac temps at idle - Celsius


20" iMac temps at idle - Fahrenheit

[haikuman]

There may be a way I can vacuum externally I will try that first.
I really appreciate your help and advice comphernation *(:>*