Over heating, Purple Grey Display, Not booting

Macbook pro 15" gets really hot real quickly even though fans are spinning. Display shows grey and purple lines that look like squares with some sort of pattern going vertically, and the mac try's to boot but goes halfway into booting process then comes up with a screen asking you to power down and power on again. Was wondering if changing the logic board will fix all of this? And if the display is messed up or just the video on the logic board.

HELP!! URGENTLY