This tutorial will help you return to Gb 2.3.6
1. First download bp v3025: Download
2. Tool loader for baseband
Turn off mobile
Restart by simultaneously pressing the Power key + Volume down to into QPST Entry mode
Download Right click on My Computer and choose Manage.
Left-click Device Manager,
check the connection between port smart one and PC COM port.
In Figure is COM3 Click left on Device Manager
Port: You enter the COM port number connected at the top.
BP SW Path: Select path to link folders WCDMA_V3025
Click Download to the free software update
3. Reinstall CWM of A5 Eng
4. Restore the stock ROM or up rom XPERIA (note format and full wipe)
5. After retore and up Dalvik wipe and wipe battery 1 again
6. Reboot the phone and experience with the above.