Chosen Solution

I hope find some help around Redditors who know things way better than me. Long Short story I try to pry open my Retina Display Macbook Pro 13" from early 2015 if I’m not mistaken to make sure is it SATA / M.2 NVME SSD inside and turns out Apple put out their proprietary standards as usual. Then I close it up, but everything back into where it suppose to be but when I try to turn it on it won’t turn on like usual. After that I realize that I leave something behind ( take a look at the picture )

How do I make it works again? any kind of helps much appreciated

It’s hard to tell from your picture, I suspect you disconnected the keyboard cable. Review this IFIXIT guide MacBook Pro 13" Retina Display Early 2015 Logic Board Replacement Jump down to Step 27 You also talk about checking your SSD. Did you take it out and/or install a different SSD into the system? Here’s a good reference on the custom Apple SSD’s The Ultimate Guide to Apple’s Proprietary SSDs