[miniman82]

You're barking up the wrong tree, troubleshooting wise.

Actual beam current is an irrelevant figure as far the the CRT is concerned, but it does matter for the regulator. You don't need to know what beam current is to figure this out. If for example you cannot get a full brightness (and not bloomed) image with the regulator out of the picture and the CRT tests good on a reliable checker, you have an issue on either side of the horizontal output transformer or the transformer itself is cooked. In short, you're not making enough HV to drive the CRT hard enough to work correctly. The giveaway is the blooming- if it's happening before you get normal screen brightness, you don't have enough HV or the supply isn't 'stiff' enough. Aka, it lacks current and you should investigate the oscillator, tubes and flyback. If that's not it the HV rectifier may be weak, the flyback may be past its prime, or you have some serious leakage to deal with somewhere. If it's a smoker set, remove and clean everything with HV on it. Believe me when I say, you will throw up at what comes off...

If on the other hand you can't get full brightness without blooming and you know the horizontal section is good, the CRT is probably gassey enough to cause excess current drain but elude detection on a CRT tester- ask me how I know this is possible...


My guess? You probably have a bad picture tube (gassey), and you need to sub another one to confirm. Appearance of shiney getters is not a reliable indication the tube hasn't gone gassey- again, ask me how I know. You need to be methodical about eliminating one thing at a time, or you'll never find the problem. I'll give you a hint- you only need just over 1ma to get a decent picture with north of 20kv on the CRT.