i cannot hear anything when i call or recieve a call, neither can person at other end hear me.

[la_decima]

I have sony xperia model C6603 version 4.4.2.
When i make a regular call or recieve a call both person cannot hear eachother.
Bt when call using viber or skype i cn hear.
How can i solve this issue?
PLEASE.HELP!

[Qatrium]

Looks like a software issue, not hardware. I'd suggest that you do a PC Companion phone repair, this will do a clean installation of the latest firmware and will also wipe your internal memory.

Open PC companion -> Support zone -> Phone/tablet software update -> Repair my phone/tablet (blue link style). Follow the steps given, do not connect your phone until prompted to press volume down while plugging USB cable.
http://www.sonymobile.com/gb/tools/pc-companion/

[Jake-SonyXperia]

Hi la_decima,

Welcome to the community,

Please make sure to backup your handset before attempting a software repair on the device. I have supplied a link below with some instructions.

Backup & Restore