When you say you “checked the capacitors”, I assume you just visually inspected them? Also, when you say “flyback does not shoot”, do you mean it’s not arcing? This doesn’t look like a flyback issue to me. I would try playing with the high voltage adjustment pot (if you can find it - should be on the neck board). To me, this looks like an issue with the power delivery to the flyback or yoke, possibly due to bad power supply. Unless you’re skilled enough to start checking voltages, the other alternative is to start recapping, starting with the power supply. Might be expensive as I suspect this monitor has a massive number of caps.