Lighting, Light Fixtures, Ceiling and Exhaust Fans - Low Voltage recessed problem

I had two low voltage cans installed in my living room to highlight some artwork. To save money, I purchased the lights myself (mistake #1). WEll, now that they are in, they dont' work. I had the electrician back out, and he said that he has power to the units, and that they SHOULD work. We even went so far as to test the bulbs, etc. Since I bought the lights myself, I've basically paid my electrician to install faulty lights. What is the best way for me to test these things myself? I have a hard time believing that BOTH lights are bad. I mean, what are the chances? I can still take them back for exchange, but I hate to unless i know for sure that the electrician didn't do something to mess them up (I tend to trust him). Worst case, the lights are faulty, I can take them back and replace them myeslf. The electrician did the hard part by setting up the switch and wiring. I'll just have to switch the fixtures out. But doesn't it seem fishy?

What is the best way for me to test these things myself?What the electrician did is as much as you can do. So either the fixtures are defective or the electrician is.