B&K 470 revjuv can't set G2 cutoff on 2 guns

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I was checking out the wg4900 tube for my Q*Bert with my B&K 470 and did a clean and balance on the green and blue guns. Now I cannot get the meter to move when I try to set the G2 cutoff for either gun, but red will still move. Did I just kill those 2 guns or am I missing something? The instructions I have don't say what to do if any of the G2 cutoff adjustments have no effect. I've used my rejuvenator successfully before so I'm not sure what I did wrong. I grabbed another 4900 tube and you can set G2 cutoff so it's not looking like a problem with the rejuvenator. Thanks for any help.
 
Do you get any reading in Test? Sometimes the socket doesn't set right, or the tension from the cables keeps it from making good contact.

I've also had cold solder joints inside my BK490 cause issues like this.

But - I've had tubes do this (recently with red on a k4900). If I give it a zap with the rejuvenation (not the clean balance), I'll usually be able to adjust the cutoff after I clear a short or whatever....
 
On a 467 there's a slide switch that let's you boost the g2 voltage for the cutoff function. Don't know if the 470 has that feature or not. If not, then zap the guns that don't set anyway.
 
Thanks for the replies Mod and Ken. Well if I have the G2 cutoffs for green and blue cranked up, the emissions test show fine for each. It might be worth noting that I can see just the smallest amount of movement out of the needle on at least one of the colors G2 cutoff. Per Ken's advice I'll give both guns a rejuv unless I should trust the emissions test and let it go at that.
 
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Well I tried a few more rejuvs on the guns and still no dice. Previously I had only had to to a clean and balance so this is the first time I've used the rejuv function. My understanding is that rejuvenation also shortens the life of the tube, so how many times can/should you try a rejuv before throwing in the towel?
 
I've done "full rejuvenation" up to ten times on a tube before it responded. See how the tube looks when connected to a gameboard video signal.

If after ten tries and the tube does not respond, then it's probably bad.
 
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Sounds like you have a short, use the button to remove shorts. It may take a few times, but should clear up your problem.
 
Okay so I got the blue back to setting the G2 voltage after another rejuv, but green still won't respond. I tried rejuvenating numerous times and checked for a short. Figuring I'm pushing my luck trying to "fix" that gun I hooked up a spare chassis to see what I could get. Sure enough the tube seems to be okay althogh the chassis I swapped in also looks to have a bad flyback. :( Guess it's a good thing I didn't swap the flyback onto the original chassis. I did notice the convergence looks a bit wonky, but until I have a stable chassis with a flyback I can actually focus I'll have to wait and see.
 
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