HP ZBook Fury 15.6 inch G8 LA-K771P REV:1.0 switch not working

[Zibbo]

I am facing a very strange problem with a HP ZBook Fury 15.6 inch G8 LA-K771P REV:1.0 laptop, the switch on the keyboard turns the laptop off but will not turn it ON. When the battery is removed the laptop turns ON and works normally and it turns off when the power button on the keyboard is pressed but once it's off it wont turn on again using the same switch.
Shorting pin number 7 to GND does not work, I have checked the motherboard under the microscope for signs of damage but found none.
What could be the possible cause of such a problem?

[mon2]

1) Link a schematic but only in the schematic forum.

2) Pin 7? Of which part?

3) Measure the voltage to ground of the ON/OFF button while it is open. Then press the button and measure the voltage to ground of the same signal while the button is pressed. Post each measurement.

[mcplslg123]

Very likely a faulty powerbutton on Keyboard. remove the keyboard and short the powerbutton key on kbd connector to rule out keyboard.