What was found
(CAN) SLAT FAILURE ON DECENT YOW, PAN DECLARED WITH ATC. NO FURTHER INCIDENT. SLAT FAIL EICAS MESSAGE ON DESCENT. QRH ACTIONS CARRIED OUT SLATS DID NOT EXTEND PAST 0 ZERO INDICATION. CMC INTERROGATED FAULT CODE RECORDED 27831005AC3. SLAT HARNESSES AT POS SLAT 2, 3 AND SLAT 3, 4. REPLACED IAW AMM 27-83-07. OPS TEST CKS SERVICEABLE. SLAT 2, 3 PN OFF 191-17270-401, SLAT 3, 4, PN OFF 191-17272-401.