iPhone 5 "Waiting for activation"

iPhone 5 was working but some times screen goes to grey lines and phone start to reboot randomly . When disconect the battery and connect again boot OK.

I decide to check around the A6 /nand - heating a low to remove the plate as ussual . Checked the area with the microscope and all was good , reflow the plate again and the phone goes to DFU mode and when try to restore the apple logo came iTunes say waiting for iphone and that is all .Try to restore only the motherboard without screen and etc same thing.

Other thing that I saw is the phone is white but the screen is black with white logo not white screen with black logo , I think may be is some capacitor but don't have enough info

Any advice is very welcome ...

Regards