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Ok Timmy I got a funky project for ya-
I need you to find ground points on the PC boards where both of these tubes are, and
do 2 things.... With the tv turned on, measure voltage from the PC board ground to the
metal chassis ground, and see if the grounds on the PC boards where these two tubes
are have and voltage on them..... Second, that AGC pot, 2.6K is not the 6K my schematic
says it should be.... You may need to see what's going on there.....
For the 6KA8, cathode ground should be directly through the AGC pot...
For the 12BY7A, C750 - one side goes to ground... Now you have to use a part,
not the metal lugs that the circuit board is attached to, these are clearly grounded,
but just in case there is a trace broken, and it's a long loop far away from the
circuit board connections to the metal chassis.....
It's really strange for so many voltages to be off and the set still works - kind-of.
So we gotta look for some sneaky thing.... And high voltages like that,
especially on items that should be going low, kinda make me thing bad ground.....
.
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Yes you can call me "Squirrel boy"
Last edited by Username1; 01-24-2015 at 12:26 PM.
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