3D Touch Issues with i3 Pro B?

[KemarRoach]

I have installed a new 3D Touch probe on my i3 Pro B, but it will not function correctly.
Upgrading the firmware and checking the Marlin config.h and pins.h files was straightforward enough, but I can't get past the probe self tests.

It lights up red, and I have adjusted the screw in the top so that the light is just on.
I give M280 P0 S160 command and the flashing resets, but if I give the M280 P0 S10 command, the pin goes down but it immediately starts flashing again.
I have ordered another probe from Geeetech, in case it is faulty.

Where in the documentation is any reference to a) At precisely what height should the probe be adjusted to, b)How to set up the setscrew, c) How to go about fault finding problems if they arise ? The information might exist, but I cannot find it !Also the calibration procedure is confusing"assumes" that the EEPROM has been enabled in Marlin (without saying how to check this), and then says to zero the offset with M851 Z0, but that returns an error which states that the limits are -5 to -15. Why is this ?

I have wasted days on this mostly because of the lack of suitable information (just speechless YouTube videos, which are of no help).

Assistance from anyone who has a good working knowledge of what to look for, would be hugely appreciated.