HELP! defective hps bulb?

hey guys, got home tonight before 9. my 400w lamp is supposed to come on at 9 oclock... never came on. after 10 min i start wondering and i unzip the tent and plug the plug into a different outlet. the bulb lights up a light purple glow for less than a second then flashes off and never comes on even though its plugged in. i switched bulbs cause my babes need their 12 hours but this FUCKING SUCKS, i have only used this bulb for a week, not even. the mh bulb works so i know it isnt a ballast issue.

any ideas? i really wanted to use hps for flower and i dont have the money to over night another one to my house... fucking ass

Return it. Is the ballast designed for HPS..is there a switch?

i ordered it online and the ballast is a digital ballast for mh and hps. only my ballast came with a warranty (3 yr) . already ordered another bulb overnight to my place... just sucks. really didnt want this to happen.

http://www.amazon.com/iPower-GLBULBH400-400-Watt-Magnetic-Digital/dp/B005HJJ3WK/ref=sr_1_2?ie=UTF8&qid=1345081311&sr=8-2&keywords=400w+hps+bulb