I've had lights (street lights) that are NOS and have never been used for like 40 years and they work fine. It is possible that very used capacitors that all of a sudden sit unused for years are a little stubborn. I think they just need to be broken in though. The capacitor with the ballast that I put in my M-250R I think is loosing its capacitance, as the lamp takes forever to warm up fully, a tell-tale sign of a weak capacitor. I will replace it when I get the cash but right now I need money for everything and have no money for anything. I need a capacitor, fuses, a cast box and lamp for my mini-high bay, and other things too. All I have is five bucks lol.
I have no idea. HID is rather unprecticable, kinda like a domesticated wild animal, like a pet chimp. It behaves most of the time but you never know what will set it off. MH more so than anything else. I won't light up MH lamps indoors for more than a few minutes. I'll piss myself worrying about the lamp exploding (not literally of course lol). I will only light MH outdoors. That way if a lamp explodes, there's no fire risk and I don't need to worry about glass shards or mercury contamination (well I sorta do but eventually that crap will seep into the ground and disapate. Fortunately we don't have well water or that could potentially be a hazard. I personally don't like well water. I think it tastes gross, though everyone that has well water says it tastes so crisp and clean. I think it taste like $h!t lol.