MH bulb burnt out or too hot?

[catmel]

Had an interesting thing happen earlier today.. one of my Metal halide bulbs just turned itself off.. all the switches were still on. I'm guessing this means its burnt out? Sounds like a dumb question LOL... but I was just curious, since I know these bubls get pretty hot, if its something they do.. doubt it, but thought crossed my mind. I've had these lights for about 6 months, but have only used the MHs for a few weeks. I got it used, but was only told they were in use 2 months before.. which is why I was curious as well. Thanks for answering my crazy / dumb question LOL

ive also heard of ballast problems.. how else besides replacing the bulb do Iknow if its something else?

I've yet to figure out how to change the bumbs on my aqualight pro yet though .. havnet had to replace them yet.. i'm guessing unscrew the one side?