As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - FLIGHT 2493 - SUPP- AIRCRAFT RETURNED TO FIELD WHEN AFTER TAKEOFF THE PASSENGER OXYGEN MASKS DROPPED. OHMED JB10 TO GROUND, OPEN. OHMED AND MEGGERED FROM CPCP TO GROUND, NO SHORT. MEGGED JB10 CP1 PIN 410 TO GROUND, NO SHORT. CHECKED OXYGEN DEPLOY SWITCH WITH OHMETER FROM JB10CP1 PIN 69 TO JB3 PIN A7 FOR INTERMITTENT AND NORMAL OPERATION CHECK GOOD. REMOVED AND REPLACED CONTROL PANEL. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.