this is so awful, my friend had a macbook pro, the wifi is the small chip under the screen cover, he connect the cable to wifi card in the wrong side. causing L3404 to burnt. which, now the device able to boot & use, able to use USB,experiencing no wifi detect.
below test under a working screen assembly,
i replace a good L3404, 5v back, but it will cause the system to white screen, no boot.
USB mouse light will flash once then no light, but there's 5v on USB ,L4605,L4615.
i removed U3440 , while L3404 is there, the white screen persist.
most of the lines on J3401 are connected to U1400.
a1278 820-2879-B
im thinking if anyone have same experience before or schematic for the wifi chip?

attached is the boardview and schematic for the board
below test under a working screen assembly,
i replace a good L3404, 5v back, but it will cause the system to white screen, no boot.
USB mouse light will flash once then no light, but there's 5v on USB ,L4605,L4615.
i removed U3440 , while L3404 is there, the white screen persist.
most of the lines on J3401 are connected to U1400.

a1278 820-2879-B
im thinking if anyone have same experience before or schematic for the wifi chip?

attached is the boardview and schematic for the board