I have an old sony VAIO laptop which hasn't been used for a while. When I turned it on the 'VAIO' logo flashes on the screen and then the laptop switches itself off and the whole thing starts again in a continuous loop. The f8 or f10 keys do nothing but the f2 goes into the bios. I have also removed the hard drive and ram then put them back in but nothing has changed. I'm not very PC knowledgeable at all so any advice would be a great help. Thanks.