blank screen on sony vaio and not able to connect to seperate monitor...help

Does it actually turn on? Fans spin, lights, drive noises, etc...?

Even if that is true, if you can't get any video even on an external monitor, the motherboard is probably bad.

That system is about 7 years old by now, unless you know how to change the motherboard and can get one for under $100, you would be better off just getting another laptop.