Hmm..this sounds like the problems that were described to me. Screen flicker and buzzing sound. Good thing I have an analog board here with a good transformer attached. i'll just swap the whole thing out and worry about the actual transformer later.
I have one that fizzes Nicola Tesla stylee (big blue arcs of HV) the sparks come from the triper (next to where the red HT cable is attached) to the scan coil cables, looks great in the dark. Kaput
excessive shorted turns in the primary of the flyback will cause the flyback, and the horizontal output transistor to run excessively hot. Keep this in mind as well.... loose cores will cause very high frequency noises.