Call in and get a quote on repair. And try cleaning the vents and reloading the OS.
I have an HP g60 notebook, ans started having problems with my screen flickering and going black. It appeared to be a hardware problem, but after leaving it unplugged for over 1 week I tried it; using only the battery as a power source and it worked fine. I continued using it until the battery was at 26%. At that point I turned it off, plugged it in, and turned it back on. Once again it could not complete the process of booting up before going to a black screen. I have an HP G60 notebook with a Vista 64 system