As some of you already know the library where I work has MH can lights, some of which run 24/7.  I noticed one yesterday a 70w MH (24/7 burner) that looked as though it was out.  Upon further examination I discovered it was extremely dim and the end of the bulb was very black.  Now keep in mind this light was working just fine a couple day prior (not dimmed at all)  What would cause it do go downhill so fast?  I know MH aren't meant to be kept running 24/7 but all of the others are running just fine.

Ok so I just had a chance to check on this light again and it is just barely glowing.  It looks like it would right at startup.  Is this typical end of life for a protected MH?  I have never seen anything like this before. The lamp is a Sylvania, and doesn't appear to be very old.

Where I worked, they had metal halide pendants inside.  They would be bright and seem normal.  Than, I'd come in one day and one would be dimmer and pinker.  It would run like that for a couple weeks, than go dim orange.  It would run like that for a day to a week, than would be completely out.
They where also run 24/7/365, but they are cycled a couple times per night to indicate alarm breaks.

Well as expected when I came in today the lamp was dead.  It is completely black on the outside, just like the one I mentioned previously where the ballast was also dead, so hopefully that is not the case this time.