A new software update which brings U.S. Cellular LG G3 US990 software version to US99023a is available now through LG Mobile Support Tool.
This is not the Android 6.0 M Update.
After the Update, Your device runs Android 5.0.1 Build RX21Y.
U.S. Cellular LG G3 US990 owners should receive the OTA update notification starting from April 18. You can also use LG Mobile Support Tool to install the Update.
The LG G3 US990 Stock firmware in KDZ format US99023a is also available for download directly from LG Server.
Download U.S. Cellular LG G3 US990 Firmware US99023a
To install the kdz firmware, You can use LG’s latest firmware flashing tool- LG UP, click here to get it,.