As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
F/A'S BROUGHT TO ATTENTION OF COCKPIT THAT IF READING LIGHTS, CALL LIGHTS AND AUDIO INOP IN B ZONE MAY EFFECT O2 GENERATORS, MAINT CONTROL CONFIRMED RETURNED TO DEPARTURE. R&R SECTION TIMER DECODER IN ZONE "B", OTBD IAW AMM 23-33 CHK OPS NORMAL. ACCOMPLISHED O2 MASK TEST DROP CHECK OPS NORMAL IAW AMM 35-20.