Chosen Solution
I bought a second hand iPhone X. The screen has been replaced with an aftermarket one. Wifi, Bluetooth and Cellular are working fine. But the GPS signal is weak. It can find the location at best up to 45 meters and does not move with me in navigation. I’ve read that there are similar problems after screen replacement, but I couldn’t find a solution anywhere. I replaced this part, which claimed to be the GPS antenna, but it didn’t work. https://www.myfixparts.com/products/oem-… (not sold on iFixit). It is claimed that there is an antenna on the middle frame, but I could not detect it. Can you help me which part should I replace?
That’s not the GPS antenna. What you replaced is most likely lower antenna tuner but I don’t have the exact schematics to confirm. The lower antenna has absolutely nothing to do with GPS, which is located on the upper side.
