I called the ballast/lamp mfgrs and had them both replaced. After waiting for the replacements, I plugged the new set in and the same thing happened. So my ballast ran my mh lamp at 600w but will only run my hps lamp at 400w. Wtf is going on? My new ballast also seems to be giving off a current that I can feel on the ballast itself as well as my hood for my lamp. Not too savy when it comes to electrical shit aside from the basics. Any feedback would be appreciated.