I've got a "no-name" clamp-on fluorescent lamp that no longer starts when the
rocker switch is snapped from the off to the on position. The lamp has a
polarized plug with an in-line black "brick" 7 1/2" x 2 1/2" x 1 3/8" that has
the code "G0138" stamped above the code "GG10051F" on the bottom but no other
markings. The 2 conductor cord from the brick goes to the base of the lamp
where the clamp is located. The lamp uses a single 18W 4 pin double tube bulb
with code G24q-2.

I'm sure that the bulb is good because I have a second, identical lamp (that
works normally) and when I swap the bulbs, the "good" lamp works perfectly with
the bulb from the lamp that is not working. I also have a brand new spare bulb
that I've tried in the non-functional fixture and it too fails to light in the
bad fixture.

The problem started spontaneously with no earlier indication of problems.
Normally, when the lamp is turned on, there are a few quick white flashes in the
bulb and the bulb lights and glows steadily. The behavior I observe is that
when I snap the rocker switch to on, the bulb either has one quick white flash
but then I only see the heaters glowing in each of the two tubes, or there is no
white flash at all, and all I see is the glow of the heater filaments. I've
tried plugging the lamp into another outlet in case the problem was related to
grounding (I've read that these quick start bulbs need their circuits and
fixtures to be grounded to work properly) but it did not help. The "brick" has
always been entirely quiet and never got particularly warm, and that has not
changed.

Any suggestions (besides ditching the lamp)?