Checked for ripple on the power rails and in all honestly it looks A-OK.
The repair manual says to isolate the 110v supply (for the CRT Circuit) unsolder 1 end of R1445, R1476 and CR1476.
R1445 happens to be a variable resistor for astig settings. The only way I can see to unsolder this is to get to the bottom of the interface board. Which would require disassembling the complete unit.
I don't think it's as easy as cutting a trace, but I'm hoping someone might be able to prove otherwise?? I really don't want to tear it down to isolate that one resistor...
Thank you