As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ZRH FLT 710 EN-ROUTE PHL TO ZRH. OVEN AT AFT A/C RIGHT GALLEY SMELLS LIKE BURNING WIRES WHEN TURNED ON. SINGLE SERVICE CART NO. A301 REPLACED BY CATERING. NO. A301 ELECTRIC INSTALLATION CHECKED. NO ANOMALIES NOTED. HEATING CHECKED ON HEATING TROLLEY. ALL NORMAL NOW.