Nokia C6 Solution Ready - QWERTY Keypad Keys connection guide

Here's the complete connection tracks of Nokia C6 QWERTY keypad keys. There are two  EMI-ESD filter chips and a  control IC, some sort of keypad data signal encoder are used in the keypad connections.

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C6 keypad keys connection layout

The C6 Keypad matrix outer and inner core layer connections configuration:

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.