I’ve actually recapped a few consumer CRT now. I’ve never really posted anything up about them, even though I originally intended to, as those sets have been passed on and were more about practice for me.
Re-capping in my experience has done very little along the lines of improving geometry in any meaningful way (though it can help but OSD settings tend to be the best place to start).
However, screen brightness generally has improved and capacitor whine reduces but appears to increase again over time which is likely why you often see blotches of some form of bonding material holding groups of capacitors together to help stop their vibrations.
For dim/dark set you might also be better adjusting the Screen pot as that controls the G1/G2 circuits inside the tube itself. This is usually found either on or close to the flyback on consumer sets as the flyback generally produces the voltages for them as a cheap method of doing so. On a broadcast monitor this is often not the case and can sometimes be found on the neck board instead.
I’d say inspect the capacitors if you see any blown out or leaking replace them and the ones around them.
Soft image is easily fixed by adjusting the focus pot on the flyback. I had to adjust this on my JVC DTV which has an insane amount of hours on it to get it sharp again.
Convergence is better tackled on the convergence rings IF OSD settings cant fix them. They are safe to touch and move by bare hand while the set is on but caution should be taken as the rear of the CRT will give you a nasty shock if you slip.
You will likely have to use a craft knife in between the rings to free them from the white epoxy that binds them together. My advice here is to absolutely NOT move the ring closest to the front of the CRT as this controls purity. If you have coloured blotches on screen then go ahead but moving this will mess up all geometry settings and they will have to be redone from scratch.
I also have to say that for convergence the test patterns in the 240p Suite are absolutely shit (you will end up having to rely on eye and some guesswork using it). You will really want to have some form of pattern generator that is outputting in 480i that can turn each of the RGB colours on and off as you adjust convergence. I still need to find and buy one myself. Just don’t expect to get everything spot on.
Concentrate on getting the center of the screen as close as possible and possibly use convergence strips around the edges to pull things in line.
Also keep an eye out for burnt IC’s and transistors as that is a sure fire way of telling if they are failing and need to be replaced.
Hope this helps?
I’m still learning new stuff all the time, but haven’t worked on a CRT in a while as want to concentrate on learning more and getting through my back logs of mods/repairs for other things first.
Edit:
Seems some of my image links are busted in some of my original posts in here, that i was hosting. Will have to try to sort them out sometime.