NOS Power Twist not working

It shouldn't be emitter loss if it was actually new, not unless there was some kind of defect in the lamp or ballast. It's probably contamination caused by an air leak. If you're lucky and the impurities originated from inside the lamp, you might be able to revive it. I've been successful on a couple occasions. The GE F15T12 I have over my sink worked when I first got it, but then I put it in storage for a number of months before installing it. When I took it back out it'd only glow faintly at the ends on trigger start and it blinked nonstop on preheat. I don't remember if it eventually lit or if I had to use an electronic ballast, but once I got it going and let it run for a while, it was fine. It's been years now and it still works perfectly. The second was a Duro-Test, but an F15T8. It wouldn't start on the original preheat fixture, but my other one fitted with a pulsestarter was able to strike it. That reminds me, I ought to dig that one out and see how it is. Another I should check is one of my colored 36W T8s, the blue one I think. It blinked for a good minute or so when I lit it up for the first time but it finally struck and seemed all right after that.

In short, try an electronic ballast or an electronic starter. I think there's a good chance you can get it lit again, but if air is entering, the problem will recur and inevitably get worse. I'm not too optimistic considering it was OK a couple weeks ago. At least in my experience, the stubborn lamps less likely to have leaded are those that have been out of use for an extended period. But, it's worth a shot.