LGUP — LG Firmware Flashing Guide (KDZ / TOT)
Flash official LG stock firmware (KDZ/TOT) with LGUP — enter Download Mode, choose Upgrade or Refurbish, and recover a bricked or bootlooping LG phone.
Pre-Flight Checklist
Complete ALL items before proceeding. Skipping any step increases the risk of bricking your device.
Guide Steps
Install LG USB Drivers first, then install LGUP. Running LGUP without the drivers will cause detection failures.
After installation, do NOT open LGUP yet.
Verify the firmware file name contains your device's model number (e.g. LGH870, LGM700A, LGV500). LG model numbers are on the back of the device or in Settings → About Phone → Model number.
Do not rename the firmware file.
Power off your LG device. To enter Download Mode:
- Most LG devices: Hold Volume Down + Power when the screen is black, then release Power and continue holding Volume Down.
- Alternative method: Connect the device via USB while powered off — LGUP may detect it automatically in download mode.
- Via dial code (if device is on): Dial
2945#*model#— e.g.2945#*870#for LG G6 H870.
The screen shows a Download Mode screen or remains black. The device should appear in Device Manager as "LG Mobile USB Modem" or "LGANDNETMDM".
Open LGUP (run as administrator if needed). When the device is connected in download mode, LGUP detects it automatically and shows the model number.
- Click BIN File Select and browse to your
.kdzor.totfirmware file. - Select the operation mode:
- Upgrade — Standard firmware flash (recommended). Preserves some data on supported models.
- Refurbish — Full wipe + flash, factory reset. Use this for brick recovery.
- Write DRM — Only for restoring DRM keys. Do not use unless specifically needed.
Click Start in LGUP. The tool unpacks the firmware and flashes each partition sequentially. A progress bar shows overall percentage.
Flashing typically takes 5–15 minutes depending on the firmware size and USB speed.
When complete, LGUP shows SUCCESS and the device reboots.
After LGUP completes, the LG device reboots. First boot optimizes apps — this may take several minutes and display an LG logo. This is expected behaviour.
After booting, go to Settings → About Phone → Software information and verify the firmware version and Android version match your flashed package.
Congratulations! Flash Successful!
You've successfully completed all steps. Your device should now be running the new firmware. If it's booting normally — you're done! Check the troubleshooting section below if you encounter any issues.
Troubleshooting & FAQ
Common errors and their solutions. Read this before asking for help.
The firmware file is for the wrong model, or LGUP version is incompatible with your device. Verify the exact model number (check under battery or Settings → About Phone). Try a different version of LGUP — older models may need LGUP 1.14, newer ones 1.16.
Reinstall LG Mobile Support Tool (includes all required drivers). Confirm the device is in Download mode (not just USB debugging mode). Try a different USB port and cable. On Windows 10, you may need to disable driver signature enforcement temporarily.
The firmware file is corrupt or the USB connection is unstable. Re-download the firmware, use a different USB cable (original LG cable preferred), and try a USB 2.0 port. Retry in Refurbish mode.
Yes — LGUP bypasses the bootloader lock by using the LAF (LG Android Flash) protocol, which communicates at a lower level than the bootloader. This is why LGUP can restore even devices that are completely unresponsive.
LGUP support varies by model. Some newer LG phones switched to EDL-based flashing (QFIL) rather than LAF-based LGUP. Check LG forums for your specific model. After LG discontinued its mobile division in 2021, firmware availability has also decreased.
Reference screenshots for this guide. Click any image to view full size.
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