This usually happens after a battery disconnection.
if you do not know the password, we have the solution for you, all you need is open the hidden erc (electronic research code) menu to find a 16-character erc serial number.
share the 16-character erc serial that we will use to generate an unlock code.
to reveal the erc screen on a nszt, nsdn, or any other ns series radio
1. press and hold the menu button on the right side of the unit.
2. while holding menu, turn your car's headlight switch on and off (or to sidelights and off) 3 to 4 times.
3. a hidden service menu screen will appear in japanese.
4. select the option that looks like service/information (usually the button that leads to a screen displaying a 16-digit alphanumeric code labeled erc).
nb. prize may vary depending on the radio model esp for w68 series radios