My Mac II/IIx/IIfx used to work fine but now it won boot. Why not?
You probably have one or more dead batteries. The full-size Mac II series machines used two PRAM-style batteries – one for the PRAM and the second, in series with the first, to kick-start the power supply. One or both may be dead, which will prevent the Mac from booting. See the logic board section for places to get the batteries.
