The most common problem why your Jay.-D’s screen isn’t working is bad soldering.

Look for the ones marked ''OK''

Please ensure that all the pins are correctly soldered, without any soldering bridges and any residual solder on the board. Also, keep in mind that the solder must cover the bottom of the pin. 

You can see some good and bad examples of soldering in the picture below Look for the ones marked ''OK'' Select an ImageOnce you fix your soldering joints, try again and see if the display is now working. If this does not work out, reach out to us at contact@circuitmess.com, and we’ll help you out.