Absent some fault finding capacity, yourself or others, then for self help a replacement power adaptor is about the only option. You might be able to find one on ebay. But you'll need to be prepared to write off that cost if that isn't the problem.
A medical friend was visiting and spotted my multimeter on the sideboard. "What's that?" he asked. "The electronics engineer's equivalent of your stethoscope, thermometer, and sphygmomanometer" I replied.