If the retropie console fails to boot or malfunctions, follow the below steps to fix it.

Step 1 - Carefully take out the sd card from the console.

Step 2- Download the latest operating system file from http://www.retrogamingconsole.com/downloads/ and unzip the image file.

Step 3 - Extract the downloaded .zip file to get .img file

Step 4- Use the extracted .img file to flash it to sd card using the Etcher app. (Tutorial at >> https://youtu.be/PijX8GDco-g?t=1m35s)

Step 5 - Once sd card flashes successfully, insert and secure the sdcard back into the console, Power on and the factory reset console is ready to play!