My macbook crashed and fans don't speed up.

Couple of days ago my Mac crashed. The display was cut in half and showing some weird green/white lines, apps not responding but mouse cursor working still. It was quite hot but not hotter than regular. I restarted it and situation happened again. Than I realised my fans don't speed up like they usually do when I use flash, watch movie or google maps etc. Fans are constantly at 2000rpm no matter the temperature. A while after restart happens again. I took a photo too.

Any idea what's wrong?