How do you use a multimeter?

stphnstevey

One of the lights in the bathroom has stopped working. It is one of those spotlight ones where you cut a whole in the ceiling for. There are two in the same room and only one has stopped working. I have changed the bulb for a new one with no luck.

I went up in the loft, moved the insulation and followed the wires. Each light has its own transformer, both lights are connected to a junction box and the junction box fed by one lead. I am guessing that as the other light is functioning, the fault can only be as far as the junction box.

Not sure what to do now though? I had a cursory look at the wiring and nothing seems to be lose. I didn't open up the junction box yet.

Is it worth buying a multimeter or something (I can get them fairly cheap) and checking there is power going through?

I have never used one before but would guess you just put the ends on the live cables? What sort of one would you need for this?

Are any of these any good as they are less than £10
http://www.dealextreme.com/products.dx/category.409~search.multimeter

Thanks

DatabaseError

multimeters are cheap, and can be fantastic tools, but if you don't know what you're doing (and you don't) they can be dangerous. loaner is probably right, transformers are often made quite cheaply, and are prone to failure, buy another

edit - your link is to a US site, prices in $

DatabaseError

...and another thing...
firstly, isolate the circuit (ideally using the trip switch/fuse for upstairs/downstairs lights) and check (with a screwdriver) that all the connections from junction box to the 2 transformers, and then lights, are tight and true, this will be free, and might fix it!

Farway

Before you go and do much more, try yet another bulb, or try your new bulb in the working light, it could just be your new bulb is duff

Fifer

I agree with tony. Multimeters are fantastic tools, but dangerous if you don't know what you are doing. If you understand the difference between ohms, volts and amps and also how dangerous mains electricty can be, consider it. If not, don't.

FWIW, I agree it's likely to be the transformer. Sawpping them over would be a good test. if you know what you are doing.

Avoriaz

We have R80 spotlights in our kitchen and bathroom that may be similar to yours.

A problem we have experienced is that the metal connectors inside the fitting gets pushed flat over the years and fail to make proper contact with the bulb.

The solution is to isolate the power and using a flat bladed screw driver or similar to raise or prise the metal connector up a bit so that it does contact the bulb properly.

It is essential that you do this with the power switched off.

DatabaseError

Avoriaz wrote: »

It is essential that you don't use your tongue for this whilst flicking the switch

fixed it for you!

ormus

one of the main reasons to use the multimeter is for a continuity test. (with the power off).
on the rare occasions, i really need to test the mains supply, i use a 240v mains test screwdriver. much quicker.
neither method is safe, if you dont know what you are doing though.

Rock_Bottom

The OP has not been back. Boom.!!! :rotfl:

Blacksheep1979

If you don't know how to use a multimeter please don't try anything more complicated than changing the bulb/flicking a switch.

stphnstevey

Not that I know what I am doing!, but I have put in new spur sockets and wired lights and a couple ovens in (yes, using the right cable).

My dad (a builder - but is not living in the country any more) suggested making own tester out of a spare light socket and connection block. Wire that up and see if it comes on.

He also said sometimes you can hear the transformer if put ear to it.

Tried bulb that works in other light in this light jut in case new bulbs also faulty - no luck.

Link to multimeter is Dealextreme - cheapest place for gadgets and free shiping to UK - about £10 or less for decent multimeter