screen turns black, and jumps blue,grey,magenta,

carlos, the best way of determining of what is going on, would be to attach an external monitor. If that monitor stays normal, you know it is definitely hardware. You could try to reinstall the video drivers and see if that makes a difference. If not, I would start by looking at the LCD ribbon cable to make sure it is not broken or shortening out. you also need to check you GPU to make sure that there is no micro solder crack etc. To work on your computer, follow these guides. Hope this helps, good luck.