Depending on the age of the iBook, you may be able to use Target Disk Mode. While I don't recommend installing any software that way, it would at least be able to tell you if there is anything on the machine worth saving without having to do any open heart surgery.
There is a chance, the computer may be able to work OK or for a time, with reset, depending on where the problem really is:
•About NVRAM and PRAM:
•Resetting PoweBook and iBook Power Management Unit (PMU
Power Management Unit (PMU) http://support.apple.com/kb/HT1431
And there's that Target Disk Mode via FireWire cable as noted above.
If iBook is a white G3 or G4 (or second generation G3 colors) it should
have a FireWire400 port. The cable would vary depending on what a
newer Mac on the other end has for Firewire (ie: FW800 or FW400.)
There was an original VGA adapter for use with external display.
Hopefully this may be of help.
Good luck & happy computing!