BB Bold :: 9870 Gives Mutli Colors Lines?

My blackberyy has been working all fine for a year and tehn suddenly it gave me multi color lines and a white screen when clicking on the red button when its locked.then it turns back to normal when i click on the lock button twice :/
and when i leave the phone for a whille the screen normally sleeps when i want to light it by clicking the red button it gives a white screen,, then i have to click the lock button twice so that the phone works