Samsung Note 5 Wont power on! Or charge!

Hi all, Yesterday i repaired my old note 5 ( new screens and battery ) ive used it all day today without issue, untill i got home and the S-PEN had broken inside off it and i was trying to get it out, i tried tapping on the bottom off the phone trying to get the pen out and then the phone turnt off and started to boot up again and then turnt back off, i have just opened the phone to find the new battery cable had snapped off the battery, i have put my old battery back in but still wont turn on, or show up on computer. Can anyone tell me why this is and how to fix it? Could the battery cable snapping fried the mother board some how? Thanks