When starting up, try zapping the pRAM by holding down the following keys
Command + Option + P + R
Let it chime about 3 - 4 times, then let go and see if it boots.
What OS was on the machine before you started messing with 7.1?
I would go with OS 7.5.5, which is available at Apple's site
[This message has been edited by WillyB (edited 02-18-2001).]