19k4900 blowing fuse then smoking.

[mikenes75513]

Need fresh ideas, not that I had many to begin with.

Recapped,
I've tried to test most of the big resistors, diodes, and chiclet (polysomething) caps,
Changed the hot and the regulator.

Blew fuse again.

Disconnected deguass,
Replaced flyback (I know the k4900 flyback is supposed never fail, but I did notice that the bolt going down into it holding the top cover was broke and was rusty in the middle where it broke so I though maybe something corroded).

Fuse held. No neck glow (I dont even know if the tube is good, maybe I should test it). R601 is smoking (still measures good, I shut it down quick). That's the 3.3 10W one between the rectifier/filter cap and the regulator.

Thoughts?
Thanks

 

[mikenes75513]

No fresh ideas from the weekday crowd?

 

[mikenes75513]

Removed a jumper for the 130v supply so it's disconnected from everything. Got 153v of the regulator. Is that a regulator failure? Bad connection?

 

[mecha]

flowchart out of the Big Blue Book says the unregulated B+ voltage should be 145V, that may have been with older AC service though. so it's 153V on the unregulated side, what is it on the side closest to the fuse holder at R503? if you have the same voltage coming out both ends of that resistor, the voltage regulator is shorted and needs to be replaced. normally it looks like it should be 130V.

 

[jjhudgins]

Mine was
Doing the same. I wouldn't come on and was popping fuses. Found a diode that had failed. Replaced it and now this. TPG is on but still no image.