As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT ATTENDANTS REPORT BURNING RUBBER SMELL DURING TAKEOFF AND CLIMB IN ROW 26. THE SMELL DISSIPATED IN CRUISE. GROUNDED - YES. ACCOMPLISHED CABIN ODOR TROUBLESHOOTING REF FIM TASK 05-51 TASK 814 RAN APU BOTH ENGS AND PACKS NO DISCREPANCIES NOTED. NO HISTORY 30 DAYS COULD NOT DUPLICATE OK FOR CONTINUED SERVICE.