If your unit prompts you for a PIN, you are likely trying to enter the manufacturer’s protected hardware configuration layer rather than the consumer system clear utility. Attempting to force entry into developer menus can accidentally change your radio regions or screen touch boundaries, turning a small glitch into a hardware error. Method 1: The Standard Menu Reset (Best Practice)
If you still have access to your phone's dialer and just want to do a quick reset, you can try the standard Grundig service codes. Please note that these may not work on all firmware versions: grundig gx3800 factory reset code better