Have you removed the paper tray and checked the path the paper takes to print?
http://support-us.samsung.com/cyber/popup/iframe/pop_troubleshooting_fr.jsp?idx=374883&modelname=SCX-4300&modelcode=SCX-4300%2FXAA&session_id=&from_osc= http://www.samsung.com/us/support/SupportOwnersFAQPopup.do?faq_id=FAQ00051700&fm_seq=57474
http://www.samsung.com/us/support/owners/product/SCX-4300/XAA