If it starts to boot, the PRAM battery is unlikely to be your problem.
It looks like you have a faulty PSU or that something in your 475 is sucking up a lot of power on boot. Have you tried booting from floppy disk?
Edit: Isolate the problem. Fit a new PRAM battery.
It looks like you have a faulty PSU or that something in your 475 is sucking up a lot of power on boot. Have you tried booting from floppy disk?
Edit: Isolate the problem. Fit a new PRAM battery.