What was found
ON CLIMB OUT AROUND 10,000 FEET, THE FA'S REPORTED THAT THERE WAS A LOUD BUZZING SOUND COMING FROM THE MAPCO CONTROL PANEL IN THE AFT GALLEY AND THAT THE TREE LIGHTS WERE FLICKERING ON AND OFF. THE BUZZING AND FLICKERING STOPPED FOR A FEW MINUTES THE STARTED AGAIN MULTIPLE TIMES, UNTIL IT FINALLY STOPPED COMPLETELY. DIVERTED AND LANDED UNEVENTFULLY. REMOVED FROM SERVICE. REMOVED G1 CONTROL PANEL IAW 25-34-00-000-802. PERFORMED GVI OF ALL WIRING, TERMINAL BLOCKS, AND RELAYS FOR SECURITY, NO DEFECTS NOTED. DETERMINED WITH GL1-K1, GL1-K2. REPLACED AFOREMENTIONED RELAYS IAW Q400 20-30-16-960-801. REINSTALLED SHELF ASSEMBLY IAW AMM 25-34-00-400-802. C/W OPS CHECK OF CONTROL PANEL IAW Q400 MM 25-34-00-710-801. OPS CHECK GOOD. NO DEFECTS NOTED. RETURNED TO SERVICE.