65 maggie

[timmy]

12gn7 pins- 1 6.15 v 2 4.30 v 7 255 v 8 122 v 9 0 v

[DaveWM]

Does the contrast control work?

[DaveWM]

deleted I was wrong about a pin

[DaveWM]

those all look pretty good, if anything its driving too hard.

[timmy]

the contrast one way with the dark pic is one thing but the other way its so dark not worth trying to see.

[DaveWM]

power off, pin 1 to ground video out resistance reading? leave it connected for a min to stablize.

[timmy]

196.1 ohms pin 1 to ground after a moment connected.

[timmy]

zero ohms with tube out.

[DaveWM]

try a new blanker, and check the pin 7 (grid) of one of the diff amps (6Gu7) voltage. blank raster. check voltage with max and min CRT bias

[timmy]

dont know if this is of any help but when this set was always first turned on it was missing a color until about 30 seconds of being on so i thought it may have been one of the diff tubes taking longer to heat or conduct.

[DaveWM]

Originally Posted by timmy

zero ohms with tube out.

should have no effect.

[timmy]

6gu7 pin 7 bias down 1.325v bias up -3.53v no diff bright up or down.

[DaveWM]

if new video out and blanker tubes do not help. I would focus on the crt bias circuit.

the only thing I can see in there is a pot that goes to a .22 uf cap (chroma board up front on right viewed from back) and a 220ohm resistor.

outside of that I am stumped.

[timmy]

ok the 220ohm checks 194ohms so thats good and the .22 i checked with my mfd dvom checker and it came in lower then the cap i have that is good. i dont know if the little difference in capacitance will make a difference but i can change it.

[timmy]

i thought if you pull the blanker tube out the screen is supposed to black out. well it dont its all green and bright