If it has an internal HD, I had some sucess getting one going by doing something that may seem pretty scary to some.
I opened the SE and disconnected the drive from the system. That includes power and data. I then powered up the machine, waited for it to try to boot, then plugged in the power. The drive started spinning. I then turned it off, reconnected everything and closed the shell.
It has worked great since then (several months). However, let others comment on the safety of trying this before you do. I had nothing to lose, and gave it a shot.
Kelly