Unplug the lamp and try another outlet to ensure your wall plug has not stopped working (also, is the outlet controlled by a switch?) and try a differnt bulb. If not these, check the cord for damage (bent or chewed through). If the cord seems fine, then it's most likely the main assemblage. Wal-Mart or a hardware supply place sells replacements for under $5.00. The assemblage is screwed in, so loosen the nuts and or screws, pulling the whole unit out. Attach new parts. Should take about 10 min.