For now wait for the Rejuv until you mess with anything else. If it is the tube you'll now right away the voltage reading in the red and green guns will be low or non-existant.
well the red and green show nothing no matter what i do and the blue isn't doing well...... CRAP o well... it was free guess im going to have to spend a few bucks...
It may take several rejuv. attempts to get the readings up. But as Mackie stated, the tube could be unfixable. I have one here that the blue gun will not read good after several rejuv's.
I'm headed up to McKinney, TX on Saturday. Let me see what I've got in the way of working monitors. Google maps makes it look like your area would not be too far out of the way.