I have three PJ501's that I believe either the power supply is bad or the ballast is bad. They all power on just fine, they just won't light the bulb. You can hear it trying to fire, but nothing happens. I know its not a bulb issue as I've tried a couple brand new bulbs w/ no luck. Just wondering if anybody has any ideas what component would be bad? Is it something as simple as a bad capacitor? Any thoughts would be appreciated.