Black screen

Would you kindly help us confirm the following situations?

• 1. No sound, buttons lights off, black screen
• 2. No sound, buttons lights on, black screen
• 3. Have sound and buttons lights on, black screen

• How to check button lights?
• 1. Please connect power to head unit, and check the button lights if stay on or not. 
• 2. If the button lights off when you start , please find “ILL” wire (orange+white), and connect it to “ACC” wire (red). 
• More details, please kindly check this video: https://youtu.be/y5TA5ATpZFQ  

• How to check the sound?
• 1. please put some music to USB/SD card without any folder, then connect to head unit(only for the situation you set the machine to “allowed to play music  automatically when USB/SD inserted”).
• 2. If your head unit has “Band” button, please long press this button.
• 3. If your head unit has DVD/CD slot, you can test sound through playing music CD.
• More details, please kindly check this video:  https://youtu.be/OHeDgW2i-i0