HP C7769B Service Manual - Page 274

Functional Overview Service Station The purpose of the Service Station is to service the Printheads in order to guarantee their performance along their specified functional life in the following ways: n Wiping of Printheads nozzle plate surface. n Applying dissolvent on the Printheads nozzle plate surface. n Capping the Printheads when they are not printing. The Printhead also performs a spitting action in order to recover or refresh the nozzle performance, therefore the Service Station contains a Spittoon to retain the ink thus reducing the risk of ink leakage. A secondary Spittoon, which performs the same routine, is located on the left hand side of the Printer. The function of wiping is to remove ink residue and external debris from the Printhead so that good drop ejection and nozzle performance is maintained throughout the life of the Printhead. To help dissolve the ink spread on the nozzle plate and also to lubricate the wiper as it scrubs the nozzle plate, some dissolvent and lubricant (PolyEthileneGlycol 400) is applied to the Printheads nozzle plate (also by means of wiping). Also, the Aerosol Fan is located at the bottom of the Service Station, so if the Aerosol Fan fails for any reason, the complete Assembly (Service Station and Aerosol Fan) needs to be replaced. Spittoon Capping System Wiping System Service Station Motor 10-10 HP DesignJets 500 and 800 Series Printers Service Manual