Quote:
Originally Posted by timmy
the hv is a solid 5 kv weather the bright is up or down my other sets are at 4.5 kv and they are fine. .
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That is good to hear.
Then I'd check the B++ at the high side of the brightness control to ground against the other set, and substitute the video amplifier tube and compare voltages in the video amplifier circuit.
If you had a scope, you could measure the video signal on both sets starting with detection, through the video amplifier and to the CRT step-by-step and isolate the problem.
For the record:
I misspoke, in my previous post. I should have said the B++
mostly supplies the sweep, HV Osc and video output. It supplies other circuits as well, but the cathodes of those tubes connect to and supply the regular B+ . These types of circuits use less parts and saves money in manufacture, but can cause nightmares in servicing, since a voltage or current problem in a circuit that is performing fine, can cause an issue in an unrelated circuit.
These "stacked B+ circuits are easier to see in the Factory schematic than in the Sams. Both are on ETF website Technical section.
James