I tried unlocking SM-G550T using samsung tools pro but everytime I try I get the same message to downgrade the modem. The tools I am using are as follows.
- Samsung Tool PRO v.29.5 to unlock the phone
- Odin v3.09 to flash firmwares and install TWRP
The default firmware that came with the phone was G550TUVU1APF1 and I have tried changing it to G550TUVS2APL1 and G550T1UVU2AQC4 but I haven't got any success. It always gives me the same log to downgrade the modem if possible. Following is the log output given by samsung tools pro.
UNLOCK INSTRUCTIONS: Phone must be rooted! If the software can't root the phone automatically, then you must root your device manually. 1. Power on the phone. 2. Enable 'USB debugging' in 'Settings'-'Developer options' for Android 4.0 - 4.1.2 or tap 7 times on 'Build number' in 'Settings'-'About phone' to enable 'Developer options' in Android 4.2+. 3. Connect the phone to PC with USB cable, install drivers if needed. 4. Select device in ADB settings. 5. Press 'Unlock' button for direct unlock. To reset Google account activation or Samsung reactivation lock: 1. Power on the phone in download mode (turn off phone, press vol.down + home + power). 2. Connect the phone to PC with USB cable, install drivers if needed. 3. Press 'Reset FRP/React/EE' to deactivate Google/Samsung/EE account activation lock. 4. After phone reboot, go to settings and perform factory reset. Operation: Unlock Selected model: SM-G550T Software version: 29.5 Waiting ADB device... OK Reading phone info... Model: SM-G550T Android version: 6.0.1 Product code: Phone version: PDA version: G550TUVU2AQC4 CSC version: G550TTMB2AQC4 CSC country code: USA CSC sales code: TMB HW version: Phone SN: RV8H70XZZAB Chip name: EXYNOS3475 Modem board: Security patch: 2017-03-01 RF cal date: IMEI: Checking Super user right... true Reading NV data... OK Checking NV data... OK Reading data... OK Detecting MODEM... OK Reading MODEM... OK Calculating... OK Writing zTool... OK Initialization zTool... OK Running zTool, please wait... Start... OK Initialization... OK Generate and check client proof... OK Verify proof by client... OK Reading data... error (1 19) Initialization zTool... OK Running zTool, please wait... Start... OK Initialization... OK Generate and check client proof... OK Verify proof by client... OK Reading data from phone... error (0) Try downgrade modem if possible Done with Samsung Tool PRO v.29.5