As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMBOUT, RECEIVED OPEN MESSAGE AT FORWARD SERVICE DOOR SERVICE. APPROXIMATELY 15000 FEET AND DISAPPEARED ABOUT10000 FEET. PRESSURIZATION APPEARED NORMAL, NO HISSING SOUNDS OBSERVED. MAINTENANCE PERFORMED TROUBLE SHOOTING PER FIM 52-41-00-810-803-A. INSPECTED SERVICE DOOR ACTUATING AND LOCK MECHANISMS. MEASURED RIGGING OF DOOR WARNING SENSOR AND ACCOMPLISHED SATISFACTORY OPERATIONAL CHECK.