Why has my printer died?

[HCART%VAX.OXFORD.AC.UK at cunyvm.cuny.edu]

    I have a malibu printer on an IRIS 3130. The printer has been working
OK for some time, but now refuses to print. lpstat -t gives the
error message

    disabled by scheduler: can't open /dev/ttyd3

    As far as I can see, all the permissions are as they always were
and resetting them to their old values does not trigger the
scheduler. Stopping and starting the print queue has no effect.

    Could this be a hardware problem? When the scheduler complains
that it cannot open ttyd3 can it only be referring to the file /dev/ttyd3,
or could it be referring to the physical line? Would I get a different
message from lpstat if it couldn't activate the printer? Any help
much appreciated.

Hugh Cartwright, Oxford University.