Anyone here know how to check a ballast to see if they're bad? I replaced some lamps in a tanning bed and two of them won't light so guessing it's the ballast. It doesn't have starters and I checked the conections but a new ballast is $100 for that unit and don't want to get a new one if not needed. Also having trouble getting the wires out of the lamp ends,is there a trick to that? Thanks for any help.