As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ELECTRICAL BURNING SMELL FROM AFT GALLEY. P51 AND P53 CART PIGTAILS WIRES FRAYED AND HOT. RETURNED TO LHR. *S/D* AT PIGTAIL P51 FOUND CABLE CHAFED BEHIND CART CONNECTION PLUG AND BURNT AT PLUG PINS AND AT CART PLUG. AT P53 FOUND PIN BENT ON CART PLUG. REMOVED AND REPLACED PIGTAILS.