MH bulb fading in and out

[ruski]

I just moved my tank everything went fine lost 1 fish and a couple of corals. but when I went to turn on the lights only 2 of the 3 bulbs turned on. I noticed that the 3rd bulb is trying to turn on, it will spark up but never fully turn on then it will just turn off. then a couple hour or even minutes later do the same thing. All connection are good. am I looking at a new bulb?? any help would be great.