Check pins 8 and 9 on the flyback, or more accurately, the low value resistors tied to these pins . One of them (I forget exactly which), supplies the voltage to the vertical circuitry. It's possible that whichever resistor it is may be open. I have the service manual for that set, (it covers several models) if you post your e-mail in your profile I'll fire it off to you. That's one of a few possibilities, the manual may be of some help...