On Saturday, December 21, 2019 at 1:02:46 AM UTC-5, micky wrote:
In alt.home.repair, on Sat, 21 Dec 2019 09:35:11 +0630, Oumati Asami
wrote:

On 20/12/19 21:28, trader_4 wrote:
On Friday, December 20, 2019 at 3:09:49 AM UTC-5, Oumati Asami wrote:
The light in the laundry room stops working after worker had worked on
the ceiling in the next room.

There are two wires coming in to the light (or one in one out). Before I
flip the switch, both wires are not charged as tested by a tester. After
flipping the switch, both are charged. Yet, the light just won't light.

I removed the light and plug it in to a socket, it works.

Question:

1) did the test (both wires not charged and then charged after flipping
the switch) I do make sense?

This test is with the light removed? You have one cable, with two conductors
plus a ground wire? By charged, do you mean that you have 120V on
both, or some other, lower voltage? What are you connecting the other
side of the meter to? Ground?


No. Tested when the light tube was in the fixture. There is no ground
wire, no neutral inside the switch box. I used a neon tester.

Clare is probably right. One of the two wires to the lightbulb is a
neutral, but if it is cut somewhere, the voltage comes in through the
hot, goes through the lightbulb and makes the part of the neutral wire
conneecte to the lightbulb hot also.

If you take out the light bulb and especially if you use a real meter,
not a practically worthless neon tester, you'll see that one side of hte
light fixture is dead.

Actually that problem typically occurs with a VOM with a high impedance.
You could use a $150 Fluke which is a very real meter and see spurious
voltage. You won't see it with an old meter with a needle movement,
because it's not high impedance. I've never seen it with a cheap neon tester
either, they take substantial voltage to light, eg 90V, and do pass
some amount of current, so I think it's unlikely you could get it to
light from spurious voltage due to a nearby cable. The non-contact
type testers could light.