motherboard is not receiving energy

Hello, i repaired one i6 and it was all fine, then some bootloops came so i restored it (that took me 3day with all these errors) and then it was alright again.. next day i was changing housing and some parts but that board was doing this before that change, so i didnt think i somehow damaged main board, but i dont know what else have could i done.

Thank you very much for any help!!