Very Grainy Display

My old iMac running OSX 10.4.1 has suddenly decided to make the display very "grainy" and I am wondering if this is a problem with the OS or the hardware.

I tried altering the brightness and contrast but no good.

When I boot up the pc it looks fine until the wallpaper appears when it is ok for a second or two and then jumps to the grainy display.

Anyone any ideas.

Thanks.

Update your OS to a later version as the early ones were suspect. Get the latest Combo updater and try that first.

Sounds like a bad driver as a first guess. What kind of plug is the monitor using - DVI or other? Maybe the video card is going away (overheating?) and defaulting to a lower res. Also go into the Preferences>Displays and make sure what you have for a monitor is correctly identified by the system and it should allow a choice of resolutions in the pull down.

Check out your display preferences - make sure it's set to millions of colors instead of thousands, as this will make the picture appear "grainy"

kahlil88 said:

Check out your display preferences - make sure it's set to millions of colors instead of thousands, as this will make the picture appear "grainy"

Click to expand...

Excellent suggestion! I bet this is the problem. The OP's computer is probably set on 256 colors...instead of thousands or millions.

- Nick