I have Sony T715 Mobile .I am facing problem with voice speaker and all the button is not working. After putting ear phone i can speak well but without ear phone i can here caller voice but my voice can not heared by caller. Please suggest me to slove the issue.

HI you can easily remove sim lock in your sony ericsson T715 mobile using sites like OnlineGSMUnlock.com here they are providing unlock code for all mobile models at reliable cost .You first check that whether the code is available for your country and network provider .If yes then pay for it and unlock your phone .

you probally have a bad internal mic. on your phone most phone models that i have worked with dont have a volume control for the mic.

Please use an headphone to confirm the status of the phone. If you are able to hear and the caller hears you well then the phone seems alright in the electronics but the earpiece and the mic needs a replacement.
if however there is low hearing and speech clarity then the phone hardware has serious issues and needs a good check.

It may be your Ear speaker problem.Please check with the help of another person by calling another phone number and speak to him.If he hears your voice its confirm that your ear speaker is damaged.You have to replace it by giving your phone to any authorized mobile phone service center.

There are several methods for unlocking mobile phones, but codes are best one, because it is easy and safe also,
you can get the unlock code for your Sony ericsson T715 model mobile phone, through this site http://www.theunlockspot.com/sony-ericsson-t715/rs10wp9/
It provides the step by step instructions and easy methods for unlocking mobile phones at a reliable cost itself..........

For the unlock code for your Sony ericson model mobile,
you can try this site http://www.unlocking4u.com/sony-ericsson-t715/rs6wp9/
It has the best instructions and easy methods for unlocking your mobile phones..........

Change your earpiece.Need to know in phone have 3 kind of mic:1,microphone to make somebody hear our voice. 2.Ear piece to make we can hear for sombody voice. 3..Buzer to make phone ringing or louder sound when somebody speak (speaker). in that case your earpiece is not work,so change your ear pice. I hope it help.

if you cant hear caller voice. do one thing go to gallery and go to voice recorder and record some voice then save that then go to media and play recorded sound if its working means your loud speaker is working but not ear peic means (ear speaker) not working. so then you need to change ear speaker.you can do your self just watch video on online.

Sound inducers do go bad. Normal the same audio amplifier is used for both the ear piece and the speaker. Since the speak does work, it sounds like the ear piece has died.