If its not broken You'll need a multimeter to test the output, it ought to give an output even in a shaded area, Otherwise Look at the cable/connector or even a blocking diode, if you'll find it, if there isn't any hope it broken and it has manufacturing unit defect! http://sharpsolarpanels637.free-blogz.com/14998609/not-known-factual-statements-about-solar-panels-for-sale