The phone contains modified software can't update. Any solution?

[jwseegers1]

I have tried to update my Xperia T. I got a message new firmware was available (9.2.A.1.199) But whem I am asked to reconnect the USB cable while holding the volumebutton down, nothing happens. I have tried everything. I did a factory reset, stopped the firewall and virussoftware, reinstalled PC companion, but nothing works. I believe that when you connect the USB while holding the volume button, the light should turn blue, but that doesn't happen. 

It is also possible to update via the phone. but when I do this I get the message can't install. 

Does anyone has an idea what to do?

Thanks

[Hampus]

Have you modified the phones software? If yes, you are not able to use our offical program to update the phone.

[jwseegers1]

Maybe I have modified software, I don't know. I'm running android, it is not rooted. I did a factory reset, that deletes all modified software, doesn't it? How can I find out if I have modified software?

[CooSee]

hello,

please use this Software XperiFirm ( got the same Problem - coming from MIUI 4 ) and you can Download the current ROM for your device.

Use FlashTool to make an *.ftf file --->  XperiFirm and Flashtool Guide

good luck  and no guarantee 

greetings from Berlin