Ballast gone?

[vibedisco]

I found one of my old ROBE 160xt heads was shutting down after 5 mins and then restarting again 5 mins later. I noticed the bulb was trying hard to ignite so I suspected the bulb needed replacing and bought a new one. after buying a new one ive found that it hasnt solved the problem. cooling isnt a problem because ive just fitted a new 2.2w sunon fan so is the likely cause a faulty ballast?

[niclights]

Normally ballasts either work or they don't. Sounds like a thermal shutdown/cold restrike cycle to me. Either it is the fan or thermal sensor/switch is faulty.

[Richard CSL]

change the ignitor, swop with a known working unit if you have one first.

[KevinE]

Ballasts in these rarely go, they're just a large coil of wire and are more likely to blow a fuse if they go shorted turns or blow their own internal thermal fuse in which case the lamp will be permanently off in the first place.

 

The ignitor is only used to strike the lamp and switches off once the lamp has struck so has no further part once it's lit.

 

The usual fault for a good lamp shutting down and coming on again is a frayed lamp cable in one of the yoke joints.

 

It usually happens where the flex passes from the base up into the yoke. Remove the 2 plastic covers on the yoke then the metal one to expose the cables; the lamp wires are the 2 thicker black ones. Give them a gentle tug to see if the copper is broken beneath the insulation; sometimes it's obvious. The cables also pass through a silicon-rubber sleeve that may be damaged/frayed.

 

Dont allow the lamp to cycle like this in a venue; switch it off till you can get it down or else the cycling will pop the new lamp quickly.