Bad network quality after changing mic and usb c board

Hi,

yes i mean mobile phone network, and i dont touched the GSM antenna, I didn't have to put the antenna down because the down microphone and the USB socket are at the bottom...

@Dragan Milovanovic

I realize that you worked at the bottom end of the phone but did you check that the antenna is still connected OK though? Something may have shifted when you opened/closed the phone. Just by removing/replacing the display you were working near it.

@Dragan Milovanovic remove the bottom speaker again and disconnect all the connectors then reseat them all again making sure they seat properly. If the original board didn't work either then it's probably a connection problem. If possible, check the connections under magnification for bent pins etc. Good luck.

@Nigel Can you specify the critical connectors that should be checked? is there another antenna beside the one on step 18? how can I check them with a meter?

Thanks!

Also my issue has been more complicated, after replacing the charging port, I lost good reception, and the loudspeaker sounded with distortion. I ordered a new speaker, and the distortion continued, changed back to the old one, after cleaning the connections- and the distortion stopped. I also changed the gsm antenna- with no effect on the reception. I appreciate your help. Thank you