As per the USB cable the Rectangle one will go to the computer and the square one to the printer.

Resolving Connection problem with the USB cable

• Switch the USB port from your computer to an another one.
• Unplug the power chord of the printer and wait for 30 seconds and plug it back again.
• Change the USB cable.
• Check your computer control panel and make sure that the Epson EX440 printer is reflecting.

These are the procedure to resolve the connection issues in USB cable.

Paper Jam Error:

• When it comes under a paper jam take out all the papers and exit the jammed paper out of your Epson Ex 440 printer.
• Tap the paper on a flat surface and make sure everything is in equal position and place it back to your printer.
• If any of the paper is cursed or not in a good codition for printing you can take that out and start printing again.

These are the procedure to resolve a paper jam Error.