Two F4T5/CW bulbs failed
I bought three of these small 4W "under cabinet lights" (W-mart, Lights Of Am...) Model 7104
I am annoyed to say that one bulb failed after a month and another after two months.
The filament is open on one side with a dark color on the bulb.
Replacing the bulb fixed the light.
I am trying to figure out why the filament would fail as I had these lights are on all the time (24/7 path lights to let me leave off the main shop lights)
I am tempted to take one of the lights apart to see if they used a "continuous run" capacitor type circuit to heat the filament using the main Square wave output.
Edit: Yes it does use a "continuous run" filament circuit just like the cheep CF bulbs.
I'll hook it up to the scope to see if I can add a Neon bulb starter to it.
Edit again: Nope. The light needs the filament to be hot in order to keep it light.
I am not fond of LOA either.
Philips rates an F4T5 at 6000 hours life, about 6 to 8 months@ 24/7. Rated life is the hours that ONE HALF of the population of bubs is expected to achieve. Half will be less, half more.
LOA makes crap, so I would not expect any of their bulbs to last all that long. They do also warrant their bulbs and fixtures, so you might give them a call.
The start cap in the unit was 3.3nF.
This seems high since the start cap for a 13W CF is around 2.2nF
Testing shows that 1nF is enough to start even the older (darkened) bulb.
I wonder if they used the wrong capacitor ?
Buy a new fixture
Lights of America are crap fixtures, yes they are cheap but you get what you pay for. I would buy a new fixture.