Dead Vaxstation?

[Matt Dainty <matt%bodgit-n-scarper.com@localhost>]

I came to power on my Vaxstation 4000/90, S3 switch is up which I believe
is correct for using a serial terminal however I get nothing displayed.

The power LED lights up, I can hear the fans humming, the hard disk spins up
and the eight diagnostic LEDs are all lit but don't ever change, even when I
press the halt button. I know the serial terminal is good as it works on my
DEC 3000/600.

Anything I can try? I figure the Dallas DS1287 timekeeper chip probably has
a dead battery by now but that wouldn't stop the machine powering up
would it?

Matt