I just got a Lumatek 600W Ballast brand new in the box. A Mondo XTRASUN hood, and a Hydrofarm cord set. The bulb I have has been used for approx. 4 months 12/12 never 24 and never 16/8 and the previous owner said he thought it was blown, but I have a feeling he did not investigate, and maybe he just assumed it was blown when the breaker tripped? Everything is connected as the instructions read (not that its really that hard... you can't mess this up, there are two plugs, and they don't fit haha) - My bulb fires IMMEDIATELY upon plugging the ballast in - however within two to three minutes the bulb shuts off, and glows until it is cool. Could this be a blown bulb or sensor in the bulb, or could it be something bigger? Everything except the bulb is new, so I really doubt there is an issue. I just got really excited when it fired, and then all the sudden blah... I was sad again. I am running two 40W Twisty house flourescents in a white hood to sustain until I get this fixed. Advice?

I would try a new lamp, HPS lamps cycle on and off when at the end of life.