Chosen Solution
Hello, I opened the laptop to replace a faulty fan and when I put it back together the power button didn’t work. So I replaced power button module cable and still the same. However, whenever I remove the top cover (the one under the keyboard) it seems to work fine ! I’m puzzled.
Problem solved: I’ve cut the grounding ribbon between chasis and power button module and it works find now. It makes no sense what so ever, but it works.
Thanks for everybody’s input.