Look at pin 6 on the convergence connector, to which it is also connected to, that is 300v ptp there, who knows what it could have done with that signal inverted.
What would be suggested is that you go over the entire horizontal circuit with a fine tooth comb and re-check every resistor and cap, and if they do not check within 10% replace.
Also, this can check caps for leakage to some degree,
https://www.amazon.com/ALMOCN-Transi...s%2C138&sr=8-6
but, out of circuit only
