9810 question and offer

[dramsey]

Tony, I have the PCB out. There is a 5x4 array of transistors (with two more below) that I assume are the ones you're talking about.

Googling "How to test a transistor" show that it's pretty easy, as long as you know the pins (E,B,C) and whether the transistors are NPN or PNP. Of course I don't know either of these things...

Also, as I know from the 9100 restoration project a couple of years back, it may not be possible to find replacement transistors with the same electrical characteristics as the transistors HP used in the early 70s.

These transistors are apparently Motorola units, part number 2N2907A 212.