You will need to measure AC voltage and DC voltage. Sometimes the symbol used for AC is this ~ so there are usually two voltage selections on a DMM- AC and DC. https://www.google.com/url?sa=t&rct...a-multimeter&usg=AOvVaw3LxlEG4KziwCq_OhEyfWA2 Check the input wiring for correct AC voltage when you have the lamp powered up. If that is present, ck the output side for DC voltage- what driver are you using? Some info on the system you're using will help.