Psychedelic screen

Question

Psychedelic screen

I've recently started having some intermittent problems with my iMac. More specifically it is (appearing to) affecting the screen. I've a 2010 iMac running OSX10.6.8 and with a 2.93Ghz Intel Core 2 Duo. 8gb of RAM.

Basically, the screen just goes from working fine to: either as if it has taken some psychadelic concoction, or it just goes a grey shade. Sometimes, if I press the on/off switch quickly I can get the screen back. But other times I have to start from scratch and switch off completely. It seems mainly to occur while viwing the internet and last night really didn't like an airline flights webpage. It became a real pain in the end - especially as I was trying to book the flights I wanted. I'll try and attach a photo.

Hope someone can help and that the 'fix' isn't too expensive . . .

Thanks

John

Mac OS X (10.6.8)

Posted on Apr 24, 2015 11:53 AM

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Answer 1

May 13, 2015 9:18 AM in response to John Morgan02

No suggestions/ideas?

John

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Answer 2

dominic23

Level 10

83,904 points

May 13, 2015 10:14 AM in response to John Morgan02

Try Reset PRAM.

Some of the display settings are stored in PRAM.

Reset PRAM: http://support.apple.com/kb/PH14222

If this does not help, contact Apple.

Genius Bar reservation

http://www.apple.com/retail/geniusbar/

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Answer 3

May 14, 2015 12:04 PM in response to John Morgan02

Wow looks like the lcd is bad might be the graphics card. Does it look like that at startup - does the gray startup screen also look like that.

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Answer 4

Drew Reece

Level 6

10,660 points

May 14, 2015 12:27 PM in response to John Morgan02

Do you have any way to reproduce this? If so try the same action in safe boot. If not run safe mode for a few hours to see if you have the same thing appears.

Try safe mode if your Mac doesn't finish starting up - Apple Support

Note: many features will be disabled by a safe boot - test as much as possible, poor graphics performance is normal in a safe boot too…

Limited graphics performance in OS X recovery or safe mode - Apple Support

Reboot to go back into a 'normal boot'.

Try a SMC reset…

Resetting the System Management Controller (SMC) on your Mac - Apple Support

If you have the original grey install discs use Apple hardware test to check the system (one disc will have the instructions printed on it - normally hold D at startup), it may not detect all errors, but it could give you somewhere else to look.

Using Apple Hardware Test - Apple Support

Run several extended & normal mode tests & record any error messages, also try 'loop mode' (hit cmd+L to enable that mode). Also let us know if the screen goes colourful in these different modes.

An Apple Store should be able to give you a diagnosis if you can take it along, but it may help for you to do some tests first.

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