*** YOU NEED TO REGISTER ON THE FORUM BEFORE YOU CAN ACCESS THE DOWNLOAD LINK ***
INSTALLATION INSTRUCTIONS
http://www.xperiablog.net/2015/03/17/guide-to-installing-xperia-lollipop-using-xperifirm-and-flashtool/
- Open link above and skip to the section entitled “FlashTool steps”.
- As you have already downloaded the FTF firmware file, skip to the section where you need to “Flash device”.
XPERIA FIRMWARE DETAILS
This is official stock Sony Xperia firmware.
Model: Sony Xperia TL (LT30at)
Firmware version: 9.1.F.1.120_R20I
Region: US (AT&T) [1264-5716]
Android version: 4.1.2

Xperia TL_LT30at_9.1.F.1.120_US_AT&T 4.1.2
Sony Xperia TL (LT30at) Android 4.1.2 firmware - US AT&T