You have tried all the common passwords— 888888 , 168 , 000000 , admin —but the HD 2018 LED software still refuses access. Here are your next steps.
After researching dozens of user manuals, forum posts, and vendor guides, these are the most frequently reported default passwords for HD-2018 controllers and their associated software: hd 2018 led software password
Some users have developed unofficial password bypass utilities for HD series controllers. These tools inject a serial command to override authentication. from forums without scanning for viruses. A safer method: use a serial monitor (like COMspy) to capture the password as the software attempts to send data to the sign. You have tried all the common passwords— 888888