What was found
CREW REPORTED, ON APPROACH THE SMELL OF BURNING RUBBER FOR ABOUT 5 MINS. SMELL WENT AWAY AFTER LANDING. RAN BOTH ENGINES IAW AMM 71-00-00 AND SUPPLIED PACKS WITH ENGINE BLEED, NO SMELL NOTED. RAN PACKS FOR HOURS WITH APU BLEED AND NO SMELL NOTED, ACCOMPLISHED OPS TEST OF EQUIPMENT COOLING IAW AMM 21-58-00-705-120-006 AND NO MESSAGES DISPLAYED NOR SMELL NOTED. OVEN 109 IN FWD GALLEY HAD A SPILLAGE OF CHOCOLATE THAT BURNED IN THE OVEN, SUSPECT THAT WAS THE FAULT SINCE NO OTHER FAULTS WERE NOTED DURING OUR TESTS. OK TO CONTINUE.