Call problems, changed antenna, nothing change

[seckinb]

Hello,
iphone 4S, 16 gb , black.

GSM signal (fine)
call quality bad (both with speaker and earpiece)
sudden interruptions
same sim card/ different phone works fine.
the proximity sensor closes lcd but not digitizer so when you talk it can mute it.

I replaced antenna
then replaced proximity sensor

nothing changed.
This problem started right after I crashed my lcd.

lcd normally works fine, but what is going on?

[RapidRepair]

Sounds to me like a mainboard issue... Bite the bullet and upgrade to a new iPhone!