Replace the cut carriage cable & guides
W is the pinch wheel sensor
It will show you a * under the W when the pinch wheel sensor (on the back of the cutting carriage) senses a pinch wheel.
You need to replace the cut carriage cable and guides. In the repair process, I would completely clean the cable tracks (including removing and cleaning the top rail) and lube everything with Dupont Dry Teflon (you can buy this at Lowe's). The Teflon goes on wet, but drys with a slick coating. This helps to eliminating the bunching up and kinking of the cable in the top track, which is a main cause of cable failure.
It seems that you would be advised to have a qualified service tech to replace this for you. It's not rocket science, but perhaps you can watch the tech make the repair for next time. Parts are less than $50.
Case closed.
~E