yaboot question for mac ppc

[Barry]

Does yaboot depend on the pram settings of the machine -- if yaboot is
installed on the default startup disk?

I ask this because I have a useful Mac G4 with a failure in the pmu
circuitry. The only way the machine will begin the startup procedure
via the button on the box is to reset the pmu, which puts all the pram
settings back to the default. The machine would be on continually, and
restarted cold only rarely.

tia