I recently tried to install a cooltube into a 400hps system bought at htgsupply.com. I did a bit of rewiring from the ballast to the socket so the system can fit into a glass tube. The first time all the rewiring was done, everything worked perfectly, but now after I have connected all the ductwork I turn on the system but the light won't turn on. I can hear the humming of the ballast so at least I know that's still working (I think)... but I don't know if my wiring from the ballast to the socket is bad, the mogul socket is bad, or the bulb is bad 
. Is there a way I can test to see which one(s) I need to replace? HELP!! Thank you.
. Is there a way I can test to see which one(s) I need to replace? HELP!! Thank you.