Repair a 12" CRT from a Commodore CBM 8032..?

[giobbi]

Hi all,

I have an 8032-sk with a working board (some minor issues, though) and a CRT that suddenly stopped to work.

I'm sure the problem isn't the board or the connector or the power, because I swapped the monitor with another 8032-sk I have and it works.

Clues:
- It worked fine until some days ago;
- the two thin filaments in the tube become hot (red);
- When you switch the computer on while the tube is cold, after few seconds you can see an almost imperceptible green flash on the monitor
- some days ago I connected for a while a mainboard of a 3032 (40 cols., no CRTC); it worked without problem (of course, messy image). I can't say if I used it again after this, so I don't know if it stopped to work after this test;
- I checked the connectors with my multimeter and they seems to be ok;

I just have a multimeter (no scope, unfortunately) so I can't do any check in this way.

What could I check with a multimeter?

-- Giovi