display problems

i have an imac i bought in 2007 and up till about a month ago a bunch pixel lines of color starting showing up then about a week ago a large bar of white blocks the middle of the screen other then this the computer runs fine. i was thinking of just going out and buying a mac mini if i cant find a solution.

Do you have Apple care? Sounds like the GPU might be acting up, which if it is would require a logic board replacement to repair.

Take a screenshot of your desktop. If the symptoms show up on the screenshot, the graphics adapter (GPU) is probably at fault. If the screenshot is clean, then it's more than likely the display that's at fault.

Regards.

the screen shot is clean. so can the display be fixed or is it just a total loss?

Sorry to hear it's the display which appears at fault. You can't really repair a display other than to replace it. If your iMac is not covered by Apple care, a new display for the machine can be quite costly depending on the screen size. If you think you can repair it yourself, (replace the display) go the ifixit web site and price out a replacement display for your machine. At the same time, take a look at the step by step instructions for replacing it. Display replacement for an iMac is a moderately difficult repair.

iFixit: The free repair manual

Even if you were to buy a new Mini to replace the iMac, you would still need a monitor.

Regards.