a question about metal halide bulbs

[cprowler]

What ballasts are you using?

I know you said that you changed the bulb to the other ballast. How long did you run them on each ballast?

Sounds exactly like what happens to core & coil ballasts when they go bad. If they are electronic then I would get new bulbs, if that doesn't work contact the (electronic) balasts manufacturer and they should be able to figure it out.

[Tom R]

I agree with Delphinus

I had the same problem with my ML

Sounds sort of like what happens when you use a pulse-start lamp on a probe-start ballast. Do you see any markings on the ballast? If it says M57 then it's a probe-start. If it says M137 or M135 then it's a pulse-start ... odds are *pretty good* though that you have a probe-start ballast

Check your ballast and lights for compatibility.

J&L show the type of ballast required with each of their lights.

Tom R

[Brighteyes_13]

thanks for all the feedback!!

the ballasts are standard probe start. i wired both myself and feel comfortable with the connections (first year electrician.) both work wonderfully. i have had the good bulb in both for an hour plus to make sure.

thats an interesting point about the pulse start bulb idea... i never let the bulb cycle thru more than twice... hmm...
if it werent for the fact both are wired into my system now, i'd test the theory about letting it warm for more than 15 mins. both apear to be venture (good ones a 10k, bad ones a 14k), and so are the ballasts.

i do however think maybe the bulb is just worn out, and ready to be retired. the arc tube is pretty blackened.

[Delphinus]

What wattage lamps? Maybe someone has a spare lamp to lend you to test that theory out. Let me know, I'll root through my drawer-o-stuff, I might have some spares lying around.

[Brighteyes_13]

the writing is pretty worn off, its hard to tell what the wattage could be. but thanks for the offer Tony