Hey all, my friends and I have been growing out of a closet in our apartment for about three weeks now, and suddenly our light (400w HPS) has stopped working. When it's plugged in the ballast still has the same hum to it as it has before, so I was hoping that the problem would be the bulb instead of wiring. Does this sound like it could be the case? And if so, is there any place locally like Home Depot that we could pick up a replacement bulb, or will we have to wait for an online purchase? Thanks in advance!