What was found
CLT - FL 2314 - AT FL 280, A SMOKE/BURNING ODOR WAS NOTED IN THE MID CABIN. THE ODOR WOULD COME AND GO. CREW COULD NOT ISOLATE ODOR WITH ALTERNATE PACKS OR GALLEY POWER. DECISION WAS MADE TO DIVERT TO CLT. NO EMERGENCY WAS DECLARED AND THE FLIGHT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED GALLEY WORK AREAS, INCLUDING COFFEE MAKERS AND LIGHTS. NO DEFECTS NOTED. ALSO, INSPECTED CABIN LIGHT BALLASTS WITH NO DEFECTS NOTED. OPERATIONALLY CHECKED AIR CONDITIONING SYSTEM. OPS CHECKED GOOD WITH NO DEFECTS NOTED. COULD NOT DUPLICATE ODOR OR SOURCE. (M)