Samsung Galaxy Trend 3 DUOS (SM-G3502) Firmware Overview
What is the latest SM-G3502 firmware?
G3502ZNUANG1, released August 5, 2014 with Android 4.1–4.3. The archive holds 3 official builds across 1 region (CSC). Each one is the full stock ROM (flash file) for Odin, not an OTA patch.
Is the Samsung Galaxy Trend 3 DUOS still getting updates?
Most likely not: there has been no new firmware since August 2014, so Android 4.1–4.3 is the last version this model got. The final builds below are still the best choice for a clean reinstall.
All SM-G3502 firmware builds
How to Flash SM-G3502 Firmware
Put the Samsung Galaxy Trend 3 DUOS into Download Mode, load the BL, AP, CP and CSC files into Odin on a Windows PC and press Start. Use HOME_CSC to keep your data, CSC for a full wipe.