I've got an old Bravo Sempron PC which I was hoping to use for backup as I now have a Delta V3, I think it's called.
Old PC was working but I think the hard disk may have been on the way out.
All that happens now is that the fan attached to the motherboard comes on. That's it. The fan at the back of the casing doesn't work, there's no sign of the hard drive booting up, and I can't even switch off using the on/off button, I have to unplug.
I even tried to open the CD drive which seems to have its own power supply but nothing.
To be honest it could be any manner of problems, from a faulty PSU to ram to motherboard. So it depends on how much you want to get this old,you don't say how old, PC working. You could certainly try another PSU if you have one or can get one cheaply enough, that would at least rule power supply as the cause or not.