Hi, I got some “dead” motherboards to repair and I have problem with this one. It is A1778 model. It was missing some chips (BB PWR, Tristar and Audio IC), so I replaced them.
Without audio IC it was working fine, got signal and everything, but when I put audio IC back the phone starts bootlooping. I have done jumper wires, tried another chip, but it is always the same. Any ideas where might be a problem?