I "fixed" the previous problem by putting the original capacitors back. The supply apparently didn't like the new low ESR capacitors.
I am however stuck at another problem. The CRT only turns on when the system has been turned off for a while (30min+, sometimes more) The CRT power supply schematic shown in the picture below. If I turn off the device and wait a couple of minutes and turn on again, the CRT does not turn on.
3 schematics are shown.
1. CRT power supply with switch mode supply
2. CRT driver with x-, y- deflection amplifiers etc.
3. HV transformer/multiplier
As I understand the functionality of this power supply (and feel free to correct me) the CRT power supply is a switch mode supply and connected to the primary winding of the HV transformer/multiplier (also schematic below, a bit blurry). 110V is generated on a secondary winding. This 110V is used as feedback for the CRT power supply. The 110V is also used to power some x-deflection amplifiers and more on the CRT driver board (see schematic below). 2.45kV are generated for the cathode supply and CRT heater as mentioned before. 9kV is also generated for the post accelerator.
Now if I disconnect the 3x 2.45kV that is generated in the HV transformer/multiplier from the CRT driver board and by extension the CRT heater and cathode, the 110V come up nicely and are stable. If I don't, then the switch mode supply tries endlessly to start but without luck. When "cold" the 110V come up, but after like 2+ seconds of the switch mode supply trying to come up and then finally are able to.
When I am successful in turning the CRT on, it looks quite nice, i.e. no focus problems nor intensity problems.
From what I understand when a HV transformer/multiplier fails, it fails totally and completely which is why I have kind of ruled that one out. Remaining are either the CRT itself, or the CRT driver.
Any advice on how to figure out which it is, would be most helpful.