Pulled out a Cruis'n game to shop out yesterday. Picture was awfully dark. The screen control is turned all the way up, and so are the contrast and the brightness.
Pulled the chassis, tried it on a known good tube, still dark.
Capped the entire chassis. No change.
B+ is 120V.
The brightness control does practically nothing from one end of the pot to the other. The contrast, OTOH, if you turn it all the way down you get a black/white picture. Turn it up, it goes dark, then you start seeing a picture.
Guessing a resistor somewhere has gone out of spec, but which one?
And yes, I've tried other (known good) neckboards.