Okay, on with the repair of the cute li'l Trinitron CRT I got for cheap. Last episode, I saw that the HOT just stopped switching a few milliseconds after bootup (and resumed switching while the power rails were going down on poweroff). I still saw the circuit pulsing the base, so my conclusion was that the HOT must have some sort of thermal failure causing it to stop working if the internals get even moderately warm.
I bought a set of 2SC5149 units from Taobao, and this is how they arrived: they're clearly pulls, but somehow with long legs, and one has different lasering than the others. I gave all of them a quick check, and the odd one out was missing the integrated 50 ohm resistor from B to E that this transistor is supposed to have, so I discarded it.
Took one of the others, replaced my existing HOT with it and... exactly the same symptom. Huh?
