Orijinal gönderinin sahibi: originalmachead ,
== Try zapping the PRAM and a NVRAM reset == '''Hold (command-Option-P-R) at restart through three chimes.''' Followed by a (command-O-F) restart ''hold the keys down until text appears on the screen'' type '''"reset-nvram'''" (no quotes) hit return type '''"reset-all" '''(no quotes) hit return see what happens. If neither of those work then it could be the video card is going, OR''' that the thermal paste needs replacement.''' causing video problems and freezing due to overheating. Good Luck, N.