my white lights whistle??? help

I have this light and bulbs

SundialT5HOUVL

new bulbs installed July 19 2009
2 of the UVL super actinics with 2 of the UVL actinic whites

Today, and all day so far, when the whites come on, they whistle. WTF?


The fans for the light are linked to the actinics, I've ruled them out. That is, I can turn the actinics off and the fans and blues go out. It's when I turn the whites off that it stops.

I do not know if this is a bad bulb or what I hear called a ballast or something. Lights confuse the heck out of me.

The fixture itself was new back in like Nov '08. Over a year old, but not by much.

It's annoying as heck and a little disconcerting.

oh, it's not a constant steady monotone whistle... it pitches and stuff. up and down.

 

Any luck on switching the bulbs around to see whats going on??

 

not yet, i have been slammed. and don't want to do it while bulbs are hot so it limits my window.

i have plans to get up early saturday (b4 lights on) and do this.

will update...

 

forgot to update... on account that this sound magically went away I never proceeded with the test... no idea...

 

Watch the socket well sounded to me like its arching in there on the contacts ? and that will cause a over heating and socket melt down and bulb burn out . Could have been some moisture in there the give the path to ground if the sound has stopped .

 

interesting. thanks. gives me something i can look for (and be careful about). good post!