My tension pulley fixture broke where the spring attaches. I cut away the old attachment point; and drilled a hole in the fixture to the original. The carriage works well except I get an error 'Printer carrier stall'. 'check the printer for obstructions then press (check mark). No obstruction. I have removed and reinstalled cartridges and checked the 'encoder strip' and I cannot tell the difference pressing forward and back or down then up. I still get the same error message. Any ideas what is next?