"Mark" wrote in message
oups.com...
I had one with bad solder joints that I repaired and is still working.

I had a few where the starter filament on the CF tube went. I have
not had one last anywhere near 7 years. They are used outside and on
all night every night.


Most of them are rated for 6K-9K hours. The 7 year figure is assuming a few
hours a day as you'll see in the fine print. Even so, a standard lamp only
lasts about 1K.

Anybody know how much it matters if they are mounted base up or base
down regarding both light output and relibability. Base up seems to
work better but I don't have any real data.

This will depend on the design of the lamp, base up is likely to work better
at least on the spiral lamps because the dimple at the end to control vapor
pressure will be the coolest point as designed, base down it'll be hotter.