My 400W Metal Halide bulb stopped working.

I just started using a brand new 400 watt metal halide lamp and it dimly lights up so I know its not the ballast. What could it be? It just will not light up fully

is the ballast the right output for the bulb.sound like power shortage

Very first time using the MH? How long have you left it on? You do know that MH lights take a few min to work up to full brightness? If you gave it 5-10 min, then you have a problem.

This is my first grow with it still in vegetative, it was brand new when we got it so it should be solid. It turned back on finally but thank god the girls are on 24 hour cycle because i am nervous to turn it off, it takes forever to warm up.

yeah my 1000w hps takes a good 30 seconds - 1 minute sometimes to brighten all the way. Kinda scared me at first because I was like "wow this looks like a desk lamp". You should be fine to turn it off if you need to, it will turn back on.

There doesn't seem to be rhyme or reason for it, but my ballasts all take different times to "warm up" and light. And if the power goes out, or a breaker trips, they might well not light up again until they cool off, or resets or whatever it does. I don't panic unless it takes a really long time. I will say this, MH bulbs in an HPS ballast do not work. I thought I had the same problem, the bulb just had a dim spark and wouldn't come up to full light, until I figured out I was trying to use the wrong ballast.