My junk box surprises even me sometimes. I didn't have any 680K resistors in any of the little sorted bins (it's not that common a value), but I did some long searching through my box of "misc" resistors - mostly scavenged - and actually found a 1/2 watt carbon comp 680K resistor. It's kind of old and has drifted a bit (reads 780K on my meter), but it's the closest thing I had and probably close enough. Replaced the resistor and fired it up, and the G2 control works again! Took a fair bit of fiddling and adjusting, but I think I got it looking halfway decent.
https://i.imgur.com/PKnbD4X.jpg
https://i.imgur.com/ve88wQp.jpg
Purity isn't perfect, I need to adjust that:
https://i.imgur.com/B7Rb3Jj.jpg - red
https://i.imgur.com/yZBd0Fa.jpg - green
https://i.imgur.com/uBn9l4d.jpg - blue
Still needs more work, I still need to change some capacitors on the power supply board that look awful - but the set seems stable. I watched it for about an hour last night, and had no problems, no image instability, etc.
And there's a lot more that needs help - the sound doesn't work. In TV mode, I can hear only a faint static noise with the volume up all the way. In camera input mode, I can feed in audio and hear it, but it's weak and VERY distorted. Also, the tuner doesn't work - I can sort of see some noise that seems like part of the signal, but I can't get any color or sync on either the main or aux tuner. I haven't investigated these issues too deeply, but part of me wonders if the audio section and tuner draw power from the main TV chassis - those leaked out capacitors might have something to do with this.
And I messed with the Beta a bit, definitely needs belts, it kind of turns the tape reel a bit when you try to engage any of the transport controls, but fails very quickly. Eject sounds like it's attempting to put the tape back in the cassette but again, fails.
Another problem that I'll have to tackle at some point is the CRT cataracts. The worst spot is the upper right corner:
https://i.imgur.com/mvjMqiY.jpg
I've done cataract repair on normal tubes before, but I've never done a Sony, so I'd love to hear from someone who has. Is this one you can separate with heat, or do you need a hot wire? This looks different than the ordinary PVA material I'm used to, it seems almost like an oil? It's the worst in the upper right corner, here's a picture of what I'm dealing with.
https://i.imgur.com/mvjMqiY.jpg
You can see how the faceplate is definitely delaminating, but it's doing so in a different manner than normal, looks like drops of water behind the glass.
In any event... progress!
-Ian