What was found
(EMERGENCY DECLARED) HYD Y RESVOR LOW LVL ECAM MESSAGE. / DEFERRED YELLOW HYD SYS QTY IAW MEL 29-30-03A. REPLACED LOW LEVEL SWITCH OF YELLOW HYD RESERVOIR IAW A320 AMM TASK 29-13-41-400-004-A. FAULT DISPLAYED ON LOWER ECAM. DID NOT FIX ISSUE. REMOVED AND REPLACED SDAC 1 IAW AMM 31-55-34 PB 401. OP CHECKS GOOD. PERFORMED OP TEST OF YELLOW HYDRAULIC SYSTEM IAW AMM 29-13-00-710-002-A, HYD LEVEL AND PRESSURE INDICATIONS WERE NORMAL WITH NO FAULTS PRESENT. THIS CLEARS MEL 29-30-03A, DMI # 109170. (M) PROCEDURES REVERSED. INOP PLACARDS REMOVED.