MacBook Pro 13 Early 2015 A1502 turns off after chime but works after unplugging the trackpad

Hi,

So I have a MacBook Pro 13 Early 2015, which doesn't turn on. When I press the start button, the chime comes, then turns off. I was trying the usual stuff, pressing buttons and hoping for some greater power to fix the laptop. I am working in IT networking, and had opened a good couple of laptops, MacBooks and so on. So I thought that if it doesn't turn on, I just replace the logic board... after replacing, I got the exact same issue...

Sooo, I have put back the old logic board, and I thought I will only connect a few things that is absolutely necessary. And it turned on, and got a folder with the question mark (which is good, as the SSD was removed). I have started to plug back other stuff, the screen, the speakers, and so on... When I have plugged the trackpad cable back, the issue came back. It was not powering on. After removing the trackpad cable, it was working again.

I am looking for some help with this, because I have absolutely no idea why, or how does the trackpad effect the power on process for the MacBook. Please help!