1. When you connect to 24V DC power do you hear the beep sound from the PC? Or dead slience?
a. If dead slience, we need to have this unit sending back to check the Motherboard, since all the 24V power is directly to the MB and providing backlight to the LCD as well.
2. If you hear the beep sound, can you connect VGA or HDMI output from the PC to check if the MB is working?