Hoping the experts here can point me to something obvious I might be missing. After a recap, the TV was working but there were some issues with the horizontal circuit resulting in a distorted picture. I went through the 5% resistors in and around the horizontal circuit and replaced about 4-5 that were out of spec. The next powerup, the original 0.25 amp 250V fuse in the schematic below blew open. I replaced it with a new slow blow fuse of the same value. Next powerup, the horizontal output cathode 68ohm (R90) resistor to ground physically blew apart. The voltage on the cathode pin 8 is supposed to be 5V DC. It was over 200V when I checked it. I went through the circuits from top to bottom and I can't find a thing wrong with how the circuit is wired, the resistors I replaced and the wiring of the replaced electrolytic caps. This is the very start of the B+ circuitry and I'm thinking I'm missing something obvious. The speaker voice coil is good, the 5U4 is hooked up correctly, the focus coil and the focus control are fine, the power transformer ohms out as stated etc. Are there some things in the flyback I should be concerned with? Anyway, excessive voltage on the horizontal output cathode I guess is the issue. Any thoughts?
05-12-2025, 10:45 AM
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