a small array of posibilities here. usually a carriage disconnect is from really loose cable tension. A service call 0105 points to the heads failing to disconnect when they should (for cutting or cleaning or sheet sets). the print walking is from the encoder strip and or the encoder reader.
If cleaning the encoder strip with isopropyl 99% doesn't do it. cleaning the encoder reader could help as well. the encoder reader is behind the print carriage, on the right end. it's held on by one screw, but the cable that powers it is quite short, and doesn't need to be disconnected. just pull it out enough to "credit card" it with a folded alcohol soaked shop cloth or the like. make sure the power is off, not a bad idea to disconnect the power cord to be sure.
as for the 0105 a limit initialize usually takes care of that after a cable tension adjustment. If you have a nice tech they may walk it over the phone with you, it's not hard to do. same idea for cable tension, although there is a tension meter, it does have an acceptable range of tightness.
hope this helps!