display checker pattern

Question

Level 1

82 points

display checker pattern

I have a G-5 PowerMac (PPC) with 23" cinema display both circa fall 2003. The display just began overlaying a checkered/plaid looking pattern to the entire screen. The checker blocks are turquoise on a white background and red on a black background. The computer otherwise functions normally. I have tried changing display color settings and changing resolutions - the pattern stays, enlarging or shrinking with the resolution changes.

Anyone know how to fix this?

Thanks in advance.

Posted on Jun 14, 2011 6:47 PM

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Answer 1

BDAqua

Level 10

250,259 points

Jun 14, 2011 7:18 PM in response to Ira Perman

Hi Ira,

Sounds like a Video Card problem or Heat issue, two things to try...

Get Temperature Monitor to see if it's heat related...

http://www.macupdate.com/info.php/id/12381/temperature-monitor

And/or iStat Pro...

http://www.islayer.com/apps/istatpro/

If you have any temps in the 70°C/160°F range, that's likely it, especially the Graphic Proccessor.

One way to test is to Safe Boot from the HD, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, is the screen still messed up in Safe Mode...

PS. Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive

Reboot, test again.

If it only does it in Regular Boot, then it could be some hardware problem like Video card, (Quartz is turned off in Safe Mode).

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Answer 2

japamac

Level 7

24,400 points

Jun 15, 2011 2:53 AM in response to Ira Perman

Open the tower and look at the graphics card.

If it has a fan on it, is the fan clean and spinning properly?

If not, you have found the root of your heat issue.

If the card does not have a fan, the card and heat sink still need to be clean.

Most any AGP graphics machine like yours has a card that is begging for refreshment.

Most all AGP graphics G4 and G5 graphics cards need to be cleaned and have thermal compound replaced.

http://www.jcsenterprises.com/Japamacs_Page/Blog/16196A0F-952B-47ED-A9F9-91F7B0E CA431.html

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Answer 3

Ira Perman Author

Level 1

82 points

Jun 15, 2011 10:44 AM in response to japamac

Hello Japamac -

I looked at the graphics card. It was dusty but the fan was spinning. I blew out the dust with compressed air. After a night of sleep mode, the computer has gone back to normal - no visual checkering. That may change once it has been running. But for now it looks like a clean, cool running card helps.

Thanks!

Ira

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Answer 4

Ira Perman Author

Level 1

82 points

Jun 15, 2011 10:51 AM in response to BDAqua

Hello BDAqua -

Thanks for the suggestion. I ran the Apple Hardware Test - Quick Test. There was a message that indicated the problem is in the VRAM (error code: 2ATI/1/4:113-A35801-109)

I am glad the problem seems to be in the graphic card. The logic card passed the test.

I also cleaned the card and after a night of sleep mode, the checkering has disappeared. I hope it stays away.

Thanks again.

Ira

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Answer 5

BDAqua

Level 10

250,259 points

Jun 15, 2011 11:04 AM in response to Ira Perman

Great to hear, I'd keep an eye on the temps with one of those apps. 🙂

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