Ballast or metal halide problems?

My Mh Light sometimes doesnt fire, I did buy the lights pre-used and the ballast too. If I unplug my light the ballast will still make noise but the light wont fire or ark. Sometimes I can see a little blue light in the bulb and if I try enough the light will turn on. I was wondering if Its the light, maybe its used up all of its vapors? I dont know. I have it on now and I wont unplug it until my new MH light shows up in the mail. Any advice to the problem would be greatly appreciated

Are you talking about like you have it running and then turn it off, then try to turn it back on and it doesnt fire? If thats the problem then they are all like that. They need about a 30minute "cool down" in my experience before they will fire again.

Are you unplugging the ballast from the wall or from the reflector my ballast dosent make any noise when my timer is off but I have had accidents were the reflector comes unplugged from the ballast and makes horrible noises. Hope that makes sence lil high