Precision M4700 not detecting KB

My Dell Precision M4700 mobile WS is not detecting the keyboard at Boot or inside Windows 10.

I tried running the Diagnostics from the Boot menu after POST and the system is detecting the onboard KB circuitry but says the KB is not plugged in:

Same is the case in MSINFO32 and Speccy. All circuits and motherboard are shown as having no issues and on-board keyboard is port is detected by motherboard but still the KB is not being detected when I plug it in:

MSINFO32

Speccy

Also the three touchpad buttons on the top on the touchpad that are linked to the small joystick on the keyboard are also not working. Maybe they are power by the keyboard being plugged in as well? Though that a guess.

 I have tried replacing the KB but it's the same result. I have also tried testing the resistance in the ribbon cable linking the KB to MB using a voltmeter and all the individual wires are conducting current. I am stumped at the moment and any help would be greatly appreciated.