I have a g620 CPU with stock heatsink and fan which has been sitting happily in my homebuild pc running CPU intense games at around 60*C. Yesterday I turned my PC on and watched a movie and I was getting warnings of 90*C+ temperatures. The CPU was only being utilised 20% max whilst running the movie. I shut down my pc and left it for an hour or two then switched it back on to find it was giving me warnings at startup and even if I didn't run any programmes. I have checked the heatsink and fan which were in place and cant fathom how this has happened. Can anyone help?