It sounds like it may need a printer lube.
The manuals for this model are at C-tech:
XE-A102 operation and programming manual:
http://the-checkout-tech.com/manuals/cashregisters/Sharp_XE-A102_operating_and_programming_manual.html
XE-A102 Service (repair) manual:
http://the-checkout-tech.com/manuals/cashregisters/Sharp_XE-A102_service_U_and_V_ver_manual.html
Registerman
January 2012