I also looked everywhere on the Internet, but information about the location Of mi5s antennas found nothing!
I haven't been able to fix it yet. I plan to put an original frame with an antenna. Later. GPS works, but only in open areas.
Anyone knows by now which pins are for what? I have my Mi5S Plus which worked well and had good GPS / WiFi reception until I had to open it and disconnect / reconnect the battery (battery 0% issue and it would not charge) ... I have not replaced or broken anything inside the phone. But since I had to open it, the reception is bad and GPS fix take almost 10min and then it's lost very fast. Also wifi is almost lost being one wall away from router.
I tried pulling up all the pins with the tall curved tip, but it did not improve.
There is a YT video "Fix for GPS issue after replacing LCD screen on Xiaomi Mi Max 2" which covers the same topic - but a different phone. Any help appreciated.
I have replaced display+battery on one of my mi5s phones and battery on other one, had no issues with gps (but I had issues with proximity sensor, all phone connectors are very fragile and hard to plug). If you think that your problem is antenna contact loss issue - maybe you should clean all back cover contacts with alcohol, also I use compressed air to clean all dust that can get in during repairs.
Thank you @ozcanveli ! This is a great schematic. Too bad there is no breakdown of every connector in the PDF. So I've fixed my GPS connector J510 and the WiFi antenna connector J202. They both had their tips (springs) broken off - probably during my early clumsy takeaparts when the phone jumped out of my hands at the point when I opened it... Anyway I stuck a piece of aluminium foil in there, made a little ball and made it hold to what was left of the connector. Closed the phone together and it makes good contact with the casings antennas. Perfect signal now.