HPS bulb problem HELP

my HPS bulb wont fire up it just keeps doing the lightning bolt thing. does this mean its burnt or ballast? they are flowering right now i put the MH back on will this be ok

help??!?!?

think you need a new bulb if the metal halide is working with same ballest then its the bulb. the plants will continue to flower but not as well as with the HPS. allways buy your bulbs from bulb suppliers and not hydro shops.