I just re-hung my Xtra, which had run for more than five hours on the bench, and wouldn't you know the green tube blinked out half an hour into the setup?
I was beginning Raster Centering and had the brightness cranked and the contrast set to zero.
There was no sound when the tube went out, green just went away. No raster, nothing.
The cathode heater is running.

I've got VERY big heatsinks on the baseplate above the STKs, and microprocessor fans on the deflection board heatsink. I've not yet done the capacitor mod (I've got a spare deflection board that I'm planning to re-cap.)

I'll wait until morning and try again... perhaps something is thermalling.
In the meantime, anything else I should be looking for? There does not appear to be anything loose, tho I'm suspicious... The green MAY have gone out while I was lowering the deflection board.

Usually it's the neck board, but see if the wiring to the video driver board didn't work it's way out of the little sockets. That's pretty common.

I don't suppose its' the same neckboard as my 9PG Plus?

No, but you can interchange the neck boards between tubes to confirm that it is the problem.

Half a step ahead of you... I just finished flipping the red and green neckboards (boy howdy did that suck... compared to my Barco this NEC is a b!tch to work on.)

The problem stayed with the tube.

How much hope do I have that this could be the splitter? (I'm waiting for it to discharge before flipping posts.)

On Curts' advice (posted, um... "elsewhere" ;) ) I flipped the R&G video signal wires between the video out board and the video gain board. (The gain board is adjacent to the video out board in the cardcage at the back of the PJ.)
Still no love from green.
I was also asked to confirm the filiment, which is glowing happily at (perceivably) the same brightness as R&B.

Steps so far:
Swap R & G neckboards, no green video at all (not even raster.)
Swap R&G Video signal wires between Video Out board and neck cards.
Swap R&G Video signal wires between Video Out board and Video Gain board.

I'm going to try to see if the support circuit cables can reach so I can drive the green tube with the red video out, then try flipping the HV at the spliter.

No love swapping the HV at the splitter.

Moved QR (G2, I believe) to neckboard on green tube and hung QG (insulated) out of harms way. Green tube works!
Put QR back on red tube neckboard and QG back on green tube neckboard and all three tubes are again working, but green is VERY bright.

I'm being careful with wording because I've still got the red neckboard on the green tube with green signal wires, and green neckboard on red tube with red signal wires.
I'm going to try moving neckboards back where they belong to see if brightness returns to normal, but my original problem may be the G2 board or block?

Flipping the neckboards back did not resolve the brightness problem.
Cranking down the green G2 pot (I know I know, if I have to do an O'scope setup on this later I will) brought the green brightness back to normal. It took about 80 degrees of turn on the pot, tho.

And, no, I didn't spot burn the red tube by floating its' G2.

I'll be there in about 20 minutes

Chip

Missed ya, got the pahts out of tha door. I'll let you know if I can resurrect the DOC.