Also, none of the chips get any voltage on their VCC pins when the TV is not displaying.

Why did this thread abruptly stop? Is there something irreparably wrong with the CRT?

About the terms, for not confusing... The "HOT" you cite here, is the one with heatsink? Normally the one we call "HOT" is the horizontal output, and this is the directly connected to flayback, and will not show the behaviour you described (then will be the regulator transistor). And in most little TV's the HOT don't have heatsink.

It seems to really have some PSU regulator bad behaviour. Also, Indeed, the main transistor regulator can be open (the transistor you shorted the B-E), or some near it. You can remove the transistors for testing with DMM in the diode scale, to be absolutely sure.

Is good to find the schematic for the TV, or, in the absence of, you can dowload every IC datasheet to study them and plan some tests (to be sure none contribute to the regulator or control it).

For example, in my case... Too busy last times... is easy to miss to respond to some topic/thread, and then this vanishes from the list, unless the ones can respond to it manually subscribe to it, or maintain the thread windown open (I noted that the Videokarma don't automatically subscribe to the thread when one post something). So this ends lost, until the therad owner quests about/bump it.

If you have a full raster when you short the PSU transistor, the CRT have to be good, in principle... unless it have a yoke problem, but then it will distorts a lot the image or shrinks it.

I've tested many components connected to the HOT and power supply transistor, as well as the transistors themselves. All components tested are in good working order. At this point, I think the driver/generator chip might be bad, so I'll order a replacement and see if it works. Before I do that, though, I think I'll test all the other transistors on the board, in case one's bad.

All transistors are good.

Alright, coming back to this and now having an oscilloscope, most of the signals from the signal processor are within spec. However, some signals, specifically the ones present at pins 14 and 12, are dissimilar to those shown in the datasheet schematics. Linked are the datasheet and several images of the aforementioned signals. I have also removed a 6.2V zener diode next to the heat-sinked regulator transistor, and in doing so have allowed it to run without an object shorting the transistor.

Images: https://imgur.com/a/l68wpSl
Datasheet: https://pl-1.org/getproductfile.axd?...e=uPC1379C.pdf