VL2500 Spot - Lamp Issue

[GoboMan]

I have a VL2500 spot fixture whose lamp randomly decides to shut off, and then after about a minute it re-strikes and comes back on. I thought at first it was a bad lamp, so I replaced it with a new lamp, and it still has the same issue. I checked the fans for dust/blockage, and they all appear clean and both fans are spinning just fine. What else could be the issue here?

 

[Les]

It sounds like you could have a weak or failing ballast on your hands.

 

[dmx]

Also, their power supplies are very forgiving, but might not hurt to meter power going into the fixture.

 

[Erik456]

Does the relay open when the lamp douses? If so its most likely going to be a thermal. These trip when they are over 122degrees. There are two of these OT switches. If the relay doesn't trip, ballast is your most likely culprit.

 

[GoboMan]

I'm not sure if the relays open or not. It is currently in the air and I haven't been able to get in a genie and take it down yet. The spot where it is hung does get incredibly warm in the venue, especially with the lights running. It is surrounded by many Source Fours, three more VL2500's, and two HES SolaSpot Pros. However, none of the other VL's are having this issue. The thing is it never goes out when I'm standing watching it, so I haven't been able to hear any relays tripping when the lamp douses. When it does douse, however, the fixture still pans and tilts as normal, and it never recalibrates before coming back on, so I'm confident it's not a power drop issue.

I'll get some shop time in the next few days, so I plan to see what I can do in the air before taking it down. (If I can repair it in the air, that's my desired plan. In my venue, taking a VL down/up is a process that requires two people and a genie lift.) I'm going to first test the DC voltage on the out header of the ballast comms pin in the MCB. If that reads okay, I'll just sit under it with a book and wait for it to douse and listen for any relays tripping. I'll hold on replacing the ballast until that's my last option. I do have a couple gobo/color/iris assemblies in my shop. I do not, however, have any extra UV/IV assemblies, but can order one if needed.

 

[SouthFloridaSFX]

The relay should click on as soon as the unit is powered. It is located right behind the main board on the bottom. You should meter 24v across it. The hot come straight off the main board, while the ground side starts at a grounded lug in the head and moves down threw the thermal and into the arm to the relay.

 

[Captain1985]

I have a VL2500 that lamps on during calibration and will not respond to a lamp off command once it is calibrated. I have checked config, lamp is set to stay off during power up. So, is it a bad ballast or bad ignitor? What precautions should be taken when replacing either?