Originally Posted by PatrixUSA

From an amateur electrician, trouble shooting electrical issues is like detective work, you have to start with the knowns to try and isolate the unknown. Without being there and knowing how the install when down, here's how I would begin to narrow down your issue:

Bulbs, make sure the bulbs you're using work. Try placing them into another socket (one you know works) to make sure they are working.
Once confirmed your bulbs are working, make sure you have power to your socket. Use a voltmeter to assess if power is being delivered to socket. (Please make sure you know how to do this before proceeding so you can do this safely.)

If bulbs are good and power is going to sockets, then you''ll need to defer to someone with more knowledge than I have, but it's a start. Good luck.