VHO's just stopped working how to test?

[revhtree]

My dang VHO's just went out a few minutes ago. The ReefKeeper has the switch turned on but no light. They were on and then just went out for no apparent reason. Any ides on how I can check to see if this is a bulb problem or a ballast problem?

 

[revhtree]

Well as soon as I hit send they pop back on.

 

[Troylee]

if they all went out, i would say a ballast... if just one went out i would swap the bulb with one that is lit and see if it works....pretty simple test...if it happens again...