roland d-5 - frozen menu screen. any reset ?

hi, my roland d-5's menu screen is frozen on start-up. i've looked
for a way
to reset factory settings but any online references say there is 'no
ROM reset'

is this perfectly good keyboard dead or does anyone have any idea of
how to
restore normal use. worked fine since 1980-something - perfect -
suddenly
is stuck in a Mode and no controls/switches and recycling power
restores it
to normal functionality. Greatly appreciate anyone's help,

Mike in Mich
.