Nanao MS-2930 shutdown

[Arcade-Projects]

After about five minutes of being powered on with a tube I bought recently, with Twinkle Star Sprite's attract mode, my MS-2930 chassis had the screen suddenly go black (but not collapse as during a normal power-off), with audible static sounds from the tube face (like during a normal power-off!) The neck glow and deflection seemed to continue during this time. No pop sound, smoke, or smells.

I pulled the chassis, gave it a look-over, and cleaned up the black goop (whichwe have known for some time is harmless, just some potting compound from a nearby component).

After the cleanup, I powered it on. The black level was higher, making the image grey, as if SCREEN had been turned up (it's possible I nudged the knob during the cleaning though). The image puncushion was a little off, and the whole image became smaller, about 1" in on each side.

I have not measured yet, but the smaller image and warped geometry makes me think the B+ power supply has suddenly changed. I wonder if the shutdown at first was from X-ray protection acting up.

I have a 2930 parts chassis I can try swapping parts from, but I am not sure where to start. Has anyone seen these issues?

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