C6 keypad keys connection layout
Keypad Inner core layer are all connected to EMI filter 1
Line 1 - Q, W, E, R, T, Y, U, I or ( numeric 1 2 3 4 5 6 7 8)
Line 2 - A, S, D, F, G, H, J, K or ( numeric - + #)
Line 3 - Z, X, C, V, N, M, comma
Line 4 - Fn, Right shift, Sym, Ctrl, @, space, &, ?
Line 5 - O, P, L, Backspace, Period, Enter, Left shift or ( numeric 9 0 )
Line 6 - Up, Down, Left, Right, Select
Keypad Outer core layer are all connected to EMI filter 2
Line 1 - Q, A, Z, Fn, O and Volume up switch button
Line 2 - W, S, X, Right shift, P and Volume down switch button
Line 3 - E, D, C, Symbol, L, Up
Line 4 - R, F, V, Control, Backspace, DownLine 5 - T, G, N, @, Period, Left
Line 6 - Y, H, M, Space, Enter, Right
Line 7 - U, J, comma, &, Left shift
Line 8 - I, K, period, Question mark
If all corresponding keys doesn't work on each group of line connection the problem may lies on on the Keypad EMI filter IC.
If only one or up to three keys won't work or not responding the problem may only lies on the line connection that possibly being cut or open paths.
And if tried to replace a new EMI-ESD Filter IC and all the connections line paths is okay, but the problem still exists the next option is to rework or by then replace the keypad control IC marked with number 3.