As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, HEARD A POP SOUND WITH PAX DOOR WARNING INDICATION WITH PROX SYS M FAULT STATUS FAULT 1 MSG. ALSO AN ELEC BURNING SMELL & AN AFT CARGO DOOR CAUTION. TROUBLE SHOT & FOUND MAIN PAX DOOR SENSOR PX101 TO BE BAD IAW FIM 52-70-04, TRANSFERRED FAULT TO DISC NR 3M. FAULT REMAINS OPEN.