Logic Board Damage: The Wi-Fi module is integrated into the phone's main logic board (motherboard). If there's damage to the Wi-Fi chip itself, or the solder connections to it, replacing antennas won't help. This can happen from drops, liquid damage, or manufacturing defects. If a factory reset doesn't bring Wi-Fi back, and you've confirmed all antenna connections are flawless, the most probable culprit is the ***Wi-Fi chip on the main logic board***.