Why won't my phone charge or power on?

Recently replaced the screen on my phone. Had a friend do it, ever since he replaced it for me it won't charge or power on. I opened the phone up to check everything out as I replaced the charging port myself about three weeks prior to the screen breaking. Upon opening it I noticed what a called the coax cable that runs up the side of the battery is missing. I have looked online and haven't been able to figure out if this being missing is the reason it won't charge or power on. Anybody know if this is my problem.?