MH bulb problem

[RichV]

I'm having problems getting my new bulbs to fire. I have a ballast that will run two 175W MH bulbs. My old bulbs were grossly overdue to be replacedto the point that one of them burned out. They were both corallife 10,000K. I ordered three new ushios. I intended to replace the working coralife as well as the burned out one. Only one of the ushios I can get to stay lit. The other two start the initial fire and then go out. I'm now using the old bulb and the new one that will stay lit. I should note that the new bulbs cause my ballast to make a kind of thumping noise when they start to flicker. This is the case even with the one that works. I've never heard that before. What's the problem, the bulbs or the ballast?

Thanks, Rich

 

[Scooterman]

There is a difference in the way the lamps are started(fired) Probe start & Pulse start ballast. In the US we use probe start more common, I think Usho's require a Pulse start ballast, so check it out first. If your using electronic then they should light just about anything!

 

[RichV]

Thanks,
The ushios sound like a pulsing sound. I didn't know there were different types. I'm not sure why one of the bulbs would start and the other two didn't, but i'll try probe start bulbs next.

Rich

 

[Reeferdude]

I've order bulbs online that were just defective bulbs. Not sure if that's your problem but you might end up just ordering another bulb...

 

[Scooterman]

swap the bulbs on the ballast that does fire them, sounds like you have a double ballast & a single. Which one is firing the lamps?
TO be clear, please explain what you have as in how many of each & ballast manufacturers.