DesignJet 450C repair- cartridge error

HP DesignJet 450C repair DesignJet cartridge error HP DesignJet specialist repairs. http://www.hpplotter.co.uk This video shows a Designjet 450c printer with a cartridge and data error code which 99% of the time will indicate carriage failure and the odd 5% trailing cable failure. The machine is put through the startup sequence with the carriage moving over to the right and returning to the left before starting to search for the encoder - a white mark on the platen roller. It keeps searching but is obviously missing it which indicates the sensor is not working correctly - it searches until it gives up and produces the error code. This indicates the carriage needs to be replaced. A similar error could occur on all 400 Series including the 430/450/455/488 Series.