The HP Designjet 1050C and the PostScript version, the HP Designjet 1055CM, wide format printers were originally designed to operate for 5 years without requiring service. They have many built-in self-correcting features. The Designjet 1050C series of plotters are some of the best designed and built printers HP has ever produced. They produce high quality output, and are fast and reliable. At about 5 to 5.5 million cycles (cycle defined as one carriage trip across the width of the printer) the carriage belt, trailing cable and cutter, should be replaced, and thedrop detector should also be cleaned or replaced about the same interval.
The difference between the "A" version and the "B" version (Plus version) is the electronics module (Emod). The "A" models have a single unit Emod that contains the logic board, power supply, and the Ink Supply Station (ISS) board and optional Hard Disk Drive. The Plus version uses discrete boards and power supply units. The power supply is different only in the length of the cables. The ISS board and cabling are also interchangeable.
Many owners and IT people are now maintaining their own Designjet 1050C 1055CM with repair parts from LPS Computer. It is generally an easy plotter to repair.