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Old 07-21-2024, 12:04 PM
Rudy18d Rudy18d is offline
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Join Date: Jul 2024
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Sentinel 400 No High Voltage

Greetings,

Hoping to find individuals that have worked on the Sentinel 400 before to help with this issue.

I recently acquired a rough, but untouched original, Sentinel 400. First time I have worked on this deflection type TV. Long story short, I have replaced all capacitors and checked all resistors for tolerance, (including HV side). Verified all tubes and after slowly bringing up on an isolation transformer and variac, I have good filament voltages to all tubes on both chassis, expected AC/DC voltages on tuner chassis, but no B+ or HV on the picture chassis. The schematic shows basically a voltage doubling setup with two selenium rectifiers in the video chassis with the center tap of the two rectifiers is where the 115 VAC is injected via a 100 uf electrolytic capacitor. The 115 VAC shows coming from connection 12 of the chassis connector. Am I reading all of that correctly?? I just can't find where I am losing the AC coming from the tuner chassis to the video chassis. Seems like it should be easy to find but I can't and without it I obviously will have no B+. I do get 115 coming from the secondary of the transformer meant for supplying AC to the Video Chassis but once it enters the Video Chassis, I lose it. What am I missing?

Ideas or suggestions on where to look?

Thanks in advance,
Rudy
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File Type: jpg 400 1.jpg (47.2 KB, 27 views)
File Type: jpg 400 2.jpg (34.4 KB, 22 views)
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