I got parts in today and made several changes. Maybe not the best way to troubleshoot as it's hard to tell what change affected what, but see below for the changes made since the initial noted hissing, redplating on the horizontal output tube, and tripping the breaker:
- Replaced the horizontal output tube as I am not sure of it's state now
- Replaced the HV rectifier as it was glowing blue, i.e. a gassy tube
- Replaced C166, C167, C114
- Replaced R204
- Replaced R212, R214, R213 with HV resistors and centered the HV adjust pot
- Hooked up meters for testing
I installed the chassis and tried again but unfortunately tripped out the breaker. here are my notes:
- At no time did the horizontal output tube glow red
- I had the lights off several times while running and as the HV cage area started to hiss but I could not see any arcing
- The horizontal output tube current first measured at 235ma so I turned down the horizontal efficiency to bring it just under 225ma
- On the second try I remembered to hook up my DMM to measure the horizontal output grid voltage on pin 2 & 6, it measured at -56v while the schematic specs only -46v
- On the second try the horizontal output tube current measured at about 125ma, I didn't make any adjustments this time so I am not sure why it was lower
- HV measured at 24k volts on the first try and 23K volts on the second try
- I let the set cool for 30 min and tried a third test, this time the horizontal output tube current measured approx 50ma but had -68v on the grid, adjusting the horizontal efficiency didn't affect anything so I turned the set off and am at a stopping point
- I just now seen Tom's edit about checking the 1000V and 800V boost supplies so I will have to go back later and check these.
As for the picture after some fiddling with vertical control I could get a steady readable picture, it is still only B/W and blurry. I will have to look into why the horizontal output grid voltage is running 10+ volts too negative. Would this cause something to heat up, cause the high voltage hissing noise, and trip the breaker or would the symptoms point to a second issue to fix, I am open to your thoughts.