as the CMD + Ctrl + P + R does not do as you describe.
This is the key combination to reset PRAM and does not go to a Disk Editing Screen (Whatever that is)
I suspect you have an overheating problem, which you should take care of immediately.
When was the last time you cleaned out the ventilation slots on that machine?
Get yourself a can of air and blow them out.
If the machine has any warranty left on it, get it back to Apple for them to check out the video card, which may, or may not, be soldered to the logic board.
Hi, my screen has been doing this awful things where I'll be working on it, have a couple windows up, and all of a sudden the entire screen goes stripey and green-ish, freezes and flashes a little, and will not respond at all.
I talked to a Mac specialist in my area the other day, and he suggested just turning it off, leaving it to cool down for a few hours, and to restart it. Here's the instructions he gave me:
1. As soon as you press the Power putton, hold down CMMD+Ctrl+P+R. The laptop should start, and go to a disk editing screen.
2. From there, you can choose in your "start" options to Restart the computer.
3. it should start up normally the first, second, or third time.
This is a temporary fix I've had to use multiple times in the middle of big college projects after using my macbook a bit too rigorously.
If anyone would has a suggestion as to what else this might be (the specialist said a faulty video card), please post back. I'm pretty sure if it was a video card, then the restart wouldn't work.