: If you are prompted for a 4-digit code to access service menus, try the following common industry defaults: 1617 (Used by similar Android-based units). 1234 . 0000 .
While the standard reset often doesn't require a PIN, certain deep system menus or protected "Factory Settings" may prompt you for a code.
Troubleshooting Your Grundig GX3800: The Complete Factory Reset Guide
15500 (Used specifically for certain firmware update authorization). Post-Reset Configuration Checklist