As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#569, BOS-FLL. (AIRCRAFT PERFORMED AN AIR TURN BACK TO BOS) 'AFT AVIONICS DOOR OPEN IN FLT CABIN LIMITED TO 10000 MEA CABIN DID NOT PRSSURISE; PREFORMED BITE TEST OF CPC 1 AND 2 OPS CHECK OK PREFOREMED PRESSURE LEAK TEST OK PRESSURE VESSLE TO 4 PSI IN REF AMM 05-53-00-780-001-A01 PRESSURE HELD NO ABNORMAL INDICATIONS OF PRES OR DOOR INDICATION.'