On 21/12/19 21:39, trader_4 wrote:
On Friday, December 20, 2019 at 9:51:25 PM UTC-5, Oumati Asami wrote:
On 20/12/19 22:25, micky wrote:
In alt.home.repair, on Fri, 20 Dec 2019 14:39:41 +0630, 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?

2) how could the work in the other room affect the light next room? I do

I put a dimmer on the dining room light, got interrrupted in the middle
for a long time, then didn't know why the range hood didn't work. The
wire for the range hood came out of the box with the dining room light
switch. Of course the wall was right between the rooms.

You're using a real volt meter, not a neon light or something? The
lightbulb is not in the socket when you are testing the voltage to it?


I used a neon light tester. The light bulb was in the fixture.

That's why both wires tested hot. Looks like the neutral is disconnected.
With the neutral disconnected, no current flows and both sides of the
load will be at the same potential. Since you say just two wires enter
the light, the only way I can see that explains all that you reported is
this. Power comes to fixture A in the other room that was worked on.
From there, a cable goes to the switch that works fixture B, the one
that doesn't work now. One wire of that cable is
connected to incoming power hot at fixture A location. That wire is
connected to one side of the switch, the other wire connects to the other side
of the switch. Back a fixture A, another cable runs over to fixture
B, the one that won't light now. One wire of that cable connects to
the above wire coming from the switch, the other to the neutral. If
that neutral connection was undone at the fixture A location, it
would explain what you are seeing.

That's right. Neutral was disconnected somewhere after the light. It's
been fixed and is now working. Thanks to everyone who helped me.