Dimensions � 124.3 x 61.2 x 9.2 mm
Weight � 124g
Display � 4.0 inches
Resolution - 480 x 854 px (~245ppi)
CPU � 1.0 GHz Cortex A7
GPU � Andreno 200
Chip � Qualcomm MSM7227A Snapdragon S1
RAM � 512MB
Internal Memory � 4GB
MicroSD - Up to 32GB
GPRS - EDGE - HSPA
Bluetooth � Version 4.0
WiFi - 802.11a - 802.11b - 802.11g - WiFi Hotspot - WiFi Direct
Primary Camera � 5 MP with LED Flash
Secondary Camera � 2 MP
Battery - 1750mAh
Learn how to unbrick/flash or upgrade this device using flashtool from here
Note
Follow the instructions on how to flash the device carefully from the link above
I will not take responsibility on whatever may happen to your device.
Make sure you are downloading the exact ROM of the device you want to flash because
Flashing a wrong rom will make the device completely dead
(can't power on, can't charge and will not be detected by a computer)
SONY XPERIA J ST26i STOCK ROM/FIRMWARE
Android 4.1.2 Jelly Bean
375MB
ST26i_11.2.A.0.31_CE
Android 4.0.4 Ice Cream Sandwich
372MB
ST26i_11.0.A.7.5_CE
Get other sony xperia roms from here