On Saturday, July 13, 2019 at 4:48:23 AM UTC-7, wrote:
Hi Tim

So it is a power supply out of a Sun Microsystems SPARC Classic computer.
Good info; the date might be 2000 or earlier, so
there's a good chance old-line part-number xrefs will help

the PowerSupply is marked as follows on the outside
Sun P/N 300-1101-01 Rev A
Model: PEX643-30
Made by FDK Fuji Electrochemcical Co Ltd

Lots of Japanese transistors have different pinout from US types; for TO-92,
US normal is (facing flat, with wires DOWN, left to right) E-B-C
Japan normal is E-C-B
You can usually distinguish the two by a multimeter's diode-check function (assuming a working
transistor) without desoldering.


The circuit board is marked with the following
PCB1750 A06-119271D

Not easy or not marked as to the parts

the transistors in questions are TO-92 and are all on the low voltage side of the switcher.

If it helps, NTE crossreferences for (P4M) include NTE159, a general-purpose PNP
(see https://www.nteinc.com and use the crossreference search)

It is usual for one TO-92 item on the low voltage side to be a TL431 voltage reference...