The unit is question is the display board. The other functions
(anunciator, key press, control) all work. Only the display is non-
functional (as far as I can tell).
The offending part was smoked. I pieced the parts back together to get
what i believe is the correct number. That's why I'm unable to tell if
it's a PQ40 or PO40 and the "4" is a guess as well. Most of the
body(SMD part) was held in place by silocone gell applied for other
reasons.
My next attempt will to be to try either an NPN or PNP (through hole
part) in it's place and see what happens. 3 pins, nine possible
combos, 2 types, should only take an hour or so.. That's assuming it's
not a vreg, vref, fet, or duel diode..... Sure mis sam's
photofacts )


Trace the circuit, there should be a resistor in line to the base, the
emitter will usually be grounded if NPN, or connected to V+ if PNP. A little
detective work is often all it takes.