2.For 4540s models, disconnect the following cables from the system board:
(1)Speaker cable
(2)Function board/Power button board cable
(3)Fingerprint reader board cable
3.For 4440s/4441 models, disconnect the following cables from the system board:
(1)Function board/Power button board cable
(2)Finger print reader board cable
4.Position the computer upside down.
Component replacement procedures 83