Testing internal electric wiring versus halogen transformer? I have a halogen table lamp (overhead) that is no longer working....

I have a halogen table lamp (overhead) that is no longer working. Many years ago a roof escape caused the halogen transformer to fall through and once it was replaced, the muted worked again.

There have be no roof leaks since, but the lighting is failing again. I don't know whether it's a wiring problem, or the transformer. I'm inclined to ponder the latter. But how can I test it. I enjoy an outlet tester, and a voltmeter -- but I'm not sure the best way to tryout this problem.
I in recent times droppd a small bottle...
Answers:    Open light characteristic and by voltmeter tester test two most important wires to see you have 110 volt power or not .Then by ohm meter interview out coming from transformer (set it up in DC mode if is Low voltage ) and see out coming voltage is same as labled contained by transformer or not .If power is OK you have to coppers the out let .
In ground pool. fitting below the pressure indicator...
If you are VERY practical, you can use the two leads of your voltmeter at the socket.Try one organize to any grounded part of the fixture, and the other on the metal aspect of the socket.If this is a screw-in type, dance for the center point of bulb contact. Do not allow the test head to contact anything else. "hands of a surgeon" comes to mind here. If you enjoy voltage, your transformer is probably ok. If not, change the transformer.