What was found
ARRIVED IN ATL WITH AN INBOUND WRITE UP THAT READ, ON TAKEOFF RECEIVED BURNING SMELL THROUGHOUT CABIN AND COCKPIT. DISSIPATED WITHIN A FEW MINUTES. IT RETURNED 2 HRS LATER AT CRUISE FOR A FEW MINUTES (SECURED GALLEY POWER). UNABLE TO LOCATE SOURCE. RETURNED 3RD TIME BRIEFLY ON APPROACH, AFTER TROUBLE SHOOTING PER OPN 5088, FOUND THE ODOR COMING FROM INOP BALLAST AT SEAT 37DE. AFTER OPN OF PACKS, APU AND ENGS NO FURTHER ODORS NOTED. BALLAST P/N D773-11-001 AND S/N 4666 WAS CHANGED.