On Sep 14, 11:29*am, wrote:
On Mon, 14 Sep 2009 05:53:29 -0700 (PDT), beecrofter

wrote:
Try brushing your fingers down the length of the tubes, it has always
worked on cheap shoplights for me.

If this makes them start they are not properly grounded

The way it works is that there is an inter\nal field from the hot end
of the fixture to your hand, capacitively coupled thru the glass, that
starts the arc. This happens when the voltage differential between
the two ends of the bulb is not enough to strike the initial arc. If
the fixture is grounded, and the bulbs are within a couple of inches
of the fixture (metal), then the arc will start from the hot end of
the bulb to the fixture (coupled thru the glass) and that starts the
lighting. If the fixture is not grounded, then the initial arc from
the hot end of the bulb to ground does not exist, and the fixture will
not light. That is why there is usually a warning on ALL fixtures
about grounding the metal case of the fixture.