typical "failures" for thermal ribbon printers include ??? - it has been years since ... clogging of any optical sensors ... too many thermal elements burned out on thermal print head ... EEPROM went heywire coz heavy industrial machines on the same power line (or accumulation of condensate/dust on the PCB)
failures for misc. disk drives = plastic coated alloy-ribbon connectors (interfacing the moving modules) having a bad contact
usually the similar product service won't service the "competitors" trade mark coz no actual/legal access to their know how and specifics by model (date release)
if you need repair fast call to / order the proper service -- other wise it - as for what was mentioned above - may take long