[dmazgalin]

Hi! I have 8820 with problem! When i call someone i can listen another person, but can't speak... when i say something - i hear myself and another person can't hear me.
What the problem with my phone?

[Dubdub]

Is MUTE on?

Did this just start to happen? If so, what did you do just prior to noticing it?

Have you tried a battery pull?

[dmazgalin]

Start after i open box with phone i try to change Os to 4.5 but nothing hapens, i also use battery pull..but stil have this problem. I can only hear myself when i make call

[Dubdub]

Ahhh. A bit of advice. Don't mess with the OS until you know how the phone operates and you learn about function and features.

My guess is you either have a bad OS, have a bad install, or the OS did something to change the default setup.

If you can revert to the factory specs and OS, do so. Then play with the device before you try to fix it. You might even find that it isn't broken.