If neither code works, your non-volatile memory (NVRAM) might be corrupted.
If your unit is frozen or won't load the menu, you may need a physical reset.
If your GX3800 is still not working after a proper menu or hardware reset, the issue is likely a hardware failure (e.g., a dying capacitor or loose display ribbon cable), not a software glitch. In that case, contact a professional radio repair technician.
Locate the small pinhole button, typically on the front panel near the volume or power controls.