1. After the instrument is turned on, press + and - keys simultaneously to enter the setting mode
2. Press + key again to 18P, i key to set, and then press + or - key to switch the letter below to n
3. Long press i key to save and exit settings
Tips: the default password is 1212.
https://burchda-official.com/blogs/knowledge/burchda-display-error-code-18p