Peter Reilley wrote:

About 5 years ago I installed a bunch of fluorescent light
fixtures in my shop. They all used the 4 foot bulbs that
are rated for 34 watts. At the same time I bought a box
of 10 bulbs for spares. Now some of the original bulbs are
starting to go so I replaced them with my spares. More than
half of my spare bulbs are bad. They start OK but flicker
on and off continuously. When I hit a good bulb, they work
OK so the fixture is good.

Do fluorescent bulbs die with age even when not used?
I stored them next to a heating duct. In the winter they
are warmed to perhaps 130 degrees F. Would this have
an effect?

Try to flip a tube end for end around. That sometimes works.
--
SATOR AREPO TENET OPERA ROTAS
Have 5 nice days! John
******************************
--- ILN 000.000.001 ---