I have some kind of brand 5110 Voltage Calibrator I am trying to repair. I don't know what it is, maybe Digi-something. I got it many years ago.
The outside of it has 4x transistors, some of which are 2n26422.
Anyway, they are mounted with a cable harness that goes into a molex thing (like a motherboard power connector).
Two of the transistors (on each heat sink block) seem to have blue corrosion from the heat shrink under the transistor lead to the plastic connector body.
The capacitors are not leaked, and they are on the other corner of the PCB (its like a 9x11 size unit).
I am having trouble understanding why randomly 2 wires in a cable harness might have corrosion. This thing does not have batteries, the caps are far away and they don't looked like they leaked. It would be hard for corrosive material to even get into the transistor heatsink module on the back. I don't think it could wick up the square pin into the wire, its not helium 3. It would be hard for the corrosion to reach the transistor unless you dipped the unit into a pool of something standing on the back side, if anything dripped on it, it would likely not get into the well heat shrinked lead. I had to cut it off with a exacto. The board looks very good, the silk screen is in tact.
Has anyone seen wires just spontaneously corrode like that? Something with the insulation maybe? like the pigment? It looks like the orange and yellow wires have it.