here is a guid : http://www.laptoprepair101.com/laptop/2010/04/06/fixing...
that can help u fix the problem by urslef, else try to conatact HP and ask for there extended warranty. Problem is in the video chip 10000%. So its gonna be realy expensive to repaire with new MB oO.
PS: I have same laptop with same problem 2morrow i will try bake my MB and see whats gonna happen
Hope i helped.