Could also be the ballast. Some of the Home Depot T8 fixtures I've installed
use an electronic ballast which independently drives the T8 tubes. I've had
several fail in such a way that one or more tubes stop working while other
bulbs in the same fixture continue to work fine. Some of the new "programmed
rapid start" electronic ballasts use separate starting circuits which are
independent.

I've also replaced a lot of cheap 2 lamp T8 electronic ballasts where one
tube would still start but the other would not/ This is actually a common
failure mode for the lowest cost Home Depot T8 fixtures I've installed.

As Joe also points out, the connections and lampholders are suspect, and
Home Depot fixtures have really crummy lampholders on their lowest cost
fixtures.

Smarty


"Joe" wrote in message
ps.com...
On Oct 12, 7:09 pm, wrote:

snip

I replaced only the 2 tubes but I did swap them around with no
luck ....

If the problem didn't move with the lamp movement, then the wiring/
connections/ lampholders are the cause. Odds are the lamp sockets
themselves are tired, corroded, poor contact. Replacements are readily
available and easy to swap out. HTH

Joe