This 1200 PAR HMI, with 575/1200 e-ballast, has worked reliably in the past, but today has developed strange behaviour, something not seen before :
Day 1, it worked great and was on all day. Then it was turned off and during restart had an issue where the lamp pulsed once during strike but would not stay lit. Waited a while between strikes and didn't get it back on. A crew member opened it up, and the bulb looked cloudy in the middle so he figured it was a dead bulb. Changed to another bulb that had looked already used. First try striking it, same result.
We have re-seated all connections, have verified that we're energizing ballast before supplying power to head, and also to note that this unit is running on house power, not an on-site generator's output. Shoot is indoors, so dampness is not a factor. The ballast has very little time on it.
Is there anything else that we should try in terms of troubleshooting? We're nervous about repeatedly loading fresh lamps, in case something is happening that could be damaging each lamp during re-strike.