You can find all relevant troubleshooting guides for the printer on the links below:
Turn On Power
https://www.star-m.jp/products/s_print/mcprint3/manual/en/basicOperations/turningOnOff.htm
Installing paper:
https://www.star-m.jp/products/s_print/mcprint3/manual/en/basicOperations/installingPaper.htm
Paper jam:
https://www.star-m.jp/products/s_print/mcprint3/manual/en/troubleshooting/paperJam.htm
Remove rear cover:
https://www.star-m.jp/products/s_print/mcprint3/manual/en/installing/installingRearCover.htm
Connect LAN Cable:
https://www.star-m.jp/products/s_print/mcprint3/manual/en/installing/connectingLANCable.htm
FAQ:
https://www.star-m.jp/products/s_print/mcprint3/manual/en/troubleshooting/faq.htm