Help identifying a Motorola transistor (in HP 7908 PSU)

[Brent Hilpert]

David Comley wrote:
> 
> I have been trying on and off for a while to map out
> the schematic for the PSU of an HP7908 disc/tape unit.
> There's a transistor I can't identify on the board and
> I am wondering whether anyone can ID this thing for
> me. The markings show "239" and then the batwings, and
> then below that it says "4-456". Same problem for a
> number of the diodes that are labeled "GE010673".

Partial help:

"4-456" is probably a short version of the HP house number, 
the more complete number is likely "1854-0456".

If there's no manual for the 7908 on bitsavers, a (tedious)
route is find an HP manual for similar equipment (from the 
same period and which has a chance of using the same part)
and scan the parts lists for the partial number.

Real-world example: While working on the power supply for an HP 2116,
I came across a transistor stamped "3-063". The schematic and parts
lists in the HP manual showed it to correlate to HP house number
"1853-0063". The parts list then cross-ref'd this to Motorola MJ2268.

If I recall, on the occasions when I've run across this in HP equipment
from the late-60s/early-70s, the unstated prefix has been "185x".
I don't know for sure whether it could be another prefix or not.