i got home from work and my MH is not turned on. the bulb is not broken. the ballast is running but more quiet than usual. could it be the ballast being unable to fire up the bulb? i have the 150w JPJ Viper. can someone tell me what i should do?

my only guess is the ballast..
where is the unit from, does it have a warranty?
if you got it from the LFS, i would take it there and have them check it out.