Here is the forum-style post for the firmware dump. Subject: [Download] Geant GN-HD90 Original Firmware Dump (ZIP) Hello everyone,
Flash this at your own risk. Ensure your power supply is stable during the process to avoid permanent bricking. Download Dump Original Geant HD90 zip
If the box is dead (red light only), use a CH341A or similar SPI programmer to flash the 8MB chip directly. Here is the forum-style post for the firmware dump
If the box is still responsive, rename the file to G_MS-90.bin (if required by your loader) and update via the menu. Download Dump Original Geant HD90 zip