Bogy

Hello! I have a vaio VPCEG16FM, i5 with intel HD witch crashes when under load, either in games or when watching movies, but if i use it only for browsing, or downloading torrents it works ok. The screen goes black, i have to hold the power button to shut it of. I checked the temeprature with core temp, it goes up to max 70 80 C, so it's not a temperature issue, i even upgraded from a hdd to ssd, its still crashing. I tried changing video drivers, reinstalling windows, no effect. Can anyone help me please