Sir Nael . . . . . . .
Looking at the connector and its mate at the PCB with mine old eyes, I am seeing 6 connections to which I am
ramdomly assigning contacts designations 1-6 to the connector and its mate on the PCB.
I may be off 180 degrees or they may have Alfa assignments.
It is plain to see :
Pin 1 is going to the ground plane of the PCB.
2 goes to TP5
3 goes to TP4
4 goes to TP3
5 is our connection to be solved
6 is receiving the serial digital output stream from the U1 capacitive sensing keyboard interface I.C. down below
Now your job . . . .if you accept it . . .(a la Mission Impossible ) . . . . . . is to check out pin 5 on the connector that you show and its companion plug in to see if there is a wire presence on its pin 5.
If so check it out for continuity to pin 1 which is ground.
A possibility for pin 5 is to be associated with a shielded line braid around that pin 6 signal. You can at least see
if they are using shielding around line 6.
As the board stands . . . . if there is no connection / wire being associated with the pin 5 of your male plug the
connection to the pcb was just possibly being an unused floating land.
If there
was a connection where you are seeking one, likely it would be a small trace running to the foil finger
coming in towards that connection from the outer ground plane. A cleaning and magnified inspection just might reveal some minute torn foil remnants.
Then
IF your research reveals the 5 being grounded . . . the inset shows the use of a soldered in wire spiral around the connector stub over to the 2 ground plane solder connections.
PCB and CONNECTOR . . . . .
73's de Edd