is my VHO endcap causing the bulb to not fire?

[wetWolger]

I have a VHO fixture for actinic suplementation. It contains two 95watt 36in bulbs. The front bulb works fine, fires and looks perfect. Today the back bulb I found dead. I woke up this mornign and it turned on fine and normal but when teh MH went out I notice only one of my bulbs was running.

When I replaced that bulb with the working front bulb it will not fire. The ends glow like it is trying to fire but nothing happens. I have tried to reseat the bulb several times and am getting no luck.

When I put in the failed bulb in the front fixture that the working bulb came out of it will not fire. The bulb that was in the rear and will not fire is also darkened on the ends....this darken area is the same area that dimly lites on the working bulb.

My theroy is the fixture is not fireing the bulbs and the bulb trying to fire for a day ended up killing the bulb. So the question is how do I fix this? It can't be the balast because the same balast runs both bulbs. I think it may be in the connector because about 2 months ago some salt spray got on one of the ends and it smoked and even cought fire for a half second.

So is it possible that this is causing the bulb not to fail? Will this product fix it:
http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=END-CAPG&Category_Code=VHOballast
Is there any way to test? Could it even be the balast since it the other bulb on it works? Thoughts?

[reg828]

sometimes vho dont light up when not properly seated and if they are not properly seated, it will cause the socket to burn. check the socket if it is not burn and make sure the bulb is properly seated contacting the socket...

[Julio]

either that or is not properly wired.

[wetWolger]

<a href=showthread.php?s=&postid=6947154#post6947154 target=_blank>Originally posted</a> by reg828
sometimes vho dont light up when not properly seated and if they are not properly seated, it will cause the socket to burn. check the socket if it is not burn and make sure the bulb is properly seated contacting the socket...

I have checked. I have seated and re-seated the bulb. I can not get it to seat right if that is the issue. Also the socket looks burnt but I figured this was from when salt spray got on it and cought fire.

[M. Python]

Burnt end caps or blacked bulbs are caused by a loose bulb or arcing in the end cap or a high resistance in the cap due to corrosion. It is imperative that you replace the end caps or you will risk damaging the ballast or burning down your house.

[wetWolger]

<a href=showthread.php?s=&postid=6947531#post6947531 target=_blank>Originally posted</a> by M. Python
Burnt end caps or blacked bulbs are caused by a loose bulb or arcing in the end cap or a high resistance in the cap due to corrosion. It is imperative that you replace the end caps or you will risk damaging the ballast or burning down your house.

do you think this is why the one bulb will not fire? Because I have damaged my balast? If that is the case why does the front unit working on the same balast work?

[wetWolger]

bump

[M. Python]

Is it an IceCap ballast? If it is, don’t keep trying to cycle the lights or you will damage the ballast. If it is an IceCap ballast unplug it from the outlet, then disconnect the harness from the ballast. Take ohm readings from known good bulbs and install them in your fixture, then take ohm readings through your wiring, the ones with the higher resistance will show the bad end caps or loose bulbs bad bulb pins etc. That is what I do every time I replace vho bulbs to be safe, it may be over kill but I’d hate to come home after working all day to find my house a pile of ashes. I even do this if I think I may have bumped a bulb while working in the tank.