As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OPERATIONAL TEST OF SDCU 10WQ FAILS. CABIN INDICATIONS ARE NORMAL, STEP 4. A. NO FLIGHT DECK EFFECTS OCCUR (NO MSTR CAUTION, CONT CHIME OR ECAM ALERT) FOR ANY & ALL LAVS. REPLACED SDCU PER AMM, NO HELP. RE-INSTALLED ORIG UNIT. TESTED SYSTEM. TESTED SYSTEM REF AMM 26 -17-00 PG 503 AND EC-RA 2617-01002. SYSTEM PASSED TEST.