I'm thinking of a faulty deflection yoke, there can be a short in the coil. Have you tested it or do you have a spare around from another Compact Mac ?

You wrote you had recapped the Analog board: did you replace the film capacitors too including the small red one's ( above the brightness knob ) and the 3.9uf Bi-polar one + the axials ? In short everything except for the Ceramic capacitors.

Try measuring the voltage of the +12v, +5 and expecially -12v line while you power it on and it behaves weird: what values do you get ?