Dig very carefully with a small garden trowel at the location till you find the wire.

It is likely NOT very large and easily cut with a shovel, so use a small garden trowel and go gently.

I have the exact same situation. So I can find the wire...then what? I have replaced the bulb (burned out bulb was the problem in the 12 or so lights that were not working in all, but about 4 of my fixtures still do not work. How in the world to troubleshoot these, or just replace fixture and hope for best?

Thanks

Many of the less expensive outdoor systems use simple 'vampire' style terminations.

Small pieces of metal stick out in a groove and the twin line is forced into the groove.
Often a plastic cover than snaps over to hold the cable in place.

The metal tabs punch through the insulation and make contact with the wire.

They are notoriously prone to failure in wet soil.

You just have to look at the end of the lamp post and see how it supposed to be connected.

An actual soldered joint with decent electrical tape (Scotch 33+) should last a long time on a low voltage system.

This post was edited by brickeyee on Thu, Feb 7, 13 at 13:18

Thanks for the feedback, Brick, but just from some quick research, it looks like the previous homeowners (or whoever had this lighting system installed) didn't cheap out. Just one of the multi tap transformers they installed runs about $600 on Amazon (Vista Professional Lighting or something)

So assuming they didn't go the cheap route with the punch in lights, In fact, some of the direct bury connectors are above ground, and they seem to be of good quality (silicone packed caps).

I'm just trying to troubleshoot the several lights that are not working at all, without hiring an electrician, but not sure I have the knowledge to do that.