Yes.
It's hard not to agree.
18 is completely untied at the moment from everything. It is simply soldered to the contact pad, which does not lead anywhere.
As I said earlier, the resistance of the pin and the pad relative to the ground is 5 MΩ.
Indeed it is strange.
I could still make problems with power. But power is supplied from the stabilizer and the track resistance from the control point KT1 to 3 and 4 pins is 0.01 ohms.
With the micro currents that the MKL04 consumes, this resistance can be considered zero, it doesn’t fall on anything, as shown by the voltage measurements on pins 3 and 4, it is equal to the supply voltage.
But I think it is worth pausing.
In addition to the assembly on a clean PCB, I will pre-check all the tracks not only for breaks but also for conductivity, especially at vias.
To begin, mount the power and only MKL04.
In the end, I think we'll figure it out and find the reason. I hope so.
Thank you.
I will definitely report the results.