Why only my trackpad is not working?

Hello everyone

I’m having a bit of a problem with my Macbook mentioned above. Let’s start from the beggining. Some of my keys started to work strange, definetly because of mechanical defects, so I decided to do someting about it. After many failures I ordered a new one, with the new original Trackpad-Motherboard flex cable which broke because of plugging. Today everything arrived, I plugged in the new keyboard and flex cable, and You know what? Keyboard now runs perfectly, but touchpad is completly DEAD. No matter what I did, SMC and NVRAM reset, diagnostics (without any problems detected), tweaking with options, it still remains dead. I tried to plug and unplug everything again, with no effect. How is that possible, when keyboard and touchpad are going the same cable and one of them works just fine? Now I’m starting to feel a little bit depressed. Worth mentioning is that before keyboard replacement touchpad worked flawlessly. Looking for Your ideas.

Best regards