My Presario F500 keeps rebooting upon start up with no light or anything coming from the screen. I have recently sent it to 2 professionals who worked on it but didn't fix it. I dont want to waste anymore money. I do realize that there is a recall on my battery. So i run the presario without the battery using the charger only. It still does not work so the professional told me it wasnt the battery. I did however research the issue. Post were suggesting many things could go wrong. Hardware issues,Power problems, Motherboard porblems and more. As for what the particular problem is im not sure. A lot of post suggest that I press f8 rapidly upon start up but that seems not to be working. It simply restarts at its intervals. What is most fustrating is there is nothing coming from the screen so it really makes me want to give up. If you have any solutions please bring them to my attention before I unfortunatley and reluctantly buy a new laptop. If i could get the presario f500 working long enough to follow some sort of instructions that we be much appreciated.