HP 750c Service Manual - Page 39

Scheduled Maintenance In some segments of the plotter market, the customer tends to print more than the maximum number plots that the throughput allows, exceeding by far the limit of the design. When this happens the customer runs into print quality problems and continuous plotter failures. The purpose of scheduled preventive maintenance is to avoid these failures Ć ensuring a good performance during all the product life. Level of Plotter Usage These are the usage limits of the plotter: D The service station and spittoons: Limited by the number of spits, wipes and primes performed which are directly proportional to the number of plots. D The YĆaxis: The wear of the motor depends on the number of carriage cycles. The levels of friction can increase due to dust and ink accumulation on the slider rods. Given these constraints, preventive maintenance is required when the plotter usage exceeds the following thresholds: Number of plots: 20, 000 Number of carriage cycles: 4,500,000 Customers with a normal plotter usage will not require any maintenance. During the plotter life (5 years, 220 working days per year) normal plotter use means less than (on average): 20 pages per day in CAD or 12 pages per day in LFP Implementation Two of the EEROM counters are assigned to counting the number of plots and the number of carriage cycles respectively. When the plotter exceeds the limits quoted above, the front panel displays the following message: Maintenance Advised" The configuration plot also conveys the usage information, and it is accessible by the user. Usage Information Number of plots Number of carriage cycles 4-4 Preventive Maintenance C4705-90000