I have a model G7 and suddenly it suddenly froze, monitor went black. I tried to turn it off but did not react for power button even if I pushed it for 30 sec. Later it turned itself off.

When I press the power button, de caps lock starts to react but nothing else, a small noise can be heard from the vents then it turns off.

A few minutes later the keyboard lights came back but no other reaction, only the caps lock if I press power. Sometimes the vents come back on like it wants to boot itself up (I don’t touch it, does it on its own) but then it goes off. Keyboard light is still on but does not react to anything. Tries disconnecting it but doesnt change anything. 

Can you please help me out?