iphone 5 not charging

hi all i have problem with iphone 5 not charging when it’s POWER ON (pc & charger) but when the battery drop down to 0% it’s show charging after that phone power on and same problem not charging in this state (powered on)

i change battery & usb connector & cable & charge same problem
also when i put the iphone on recovery and plug it itunes reconize it

any ideas ? i read about Q2 & U2 which the solution for my problem

thanks