| Symptom | Fix | |--------------------------------|---------------------------------------------------------------------| | Stuck on LG logo | Hard reset: unplug 30 sec → plug in → press reset pinhole 10 sec | | USB not recognized | Try different USB 2.0 drive (8GB or 16GB often work better) | | “Invalid signature” error | Wrong firmware for your MP4 variant. Re-download correct one. | | No display after update | Connect via HDMI 1 (only port 1 active in safe mode) → reflash | | Ethernet/WiFi not working | Factory reset from settings → then re-update (known glitch on v04.x) |


Used when USB fails (black screen). Requires:

Typical sequence:

# Send command to enter recovery
FACTORY_UPDATE_ON
# Transfer file via XMODEM (not ZMODEM)
# Wait for checksum validation

Sometimes the "DVAJ-633" device records with a broken header. Use a dedicated MP4 repair tool (like recover_mp4 or Grau GmbH Video Repair) rather than a firmware upd.