1967 Color Sylvania video died (Mod. CF16W)

[Electronic M]

If it still has sound then it probably has B+ (if not check the B+ supply circuits).
Without the HV rectifier (3CU3) installed, and with the room dark does the Horizontal output tube plate (different from the heater which is supposed to glow) start to glow (red/orange)? If the plate stays dark that is good, but if the plate glows do NOT let it run for more than 1 minute (or damage to that expensive tube may result). If the tube plate glows (commonly called red plating), measure the grid bias. If the grid bias is somewhere around -50 to -75 volts DC then you have proper grid drive (if not the H oscillator needs work). look for shorts on the secondary side of the flyback.

Do you have the schematic for this set? If not look for the Sam's photofact for it. Schematics are essential for troubleshooting/finding your way around in a color TV.