HP 3500cp Service Manual - Page 111

D14. Printhead Continuity The purpose of this test is to display the primitives and address maps of the printheads. Perform the Printhead Continuity test as follows: 1 In the Diagnostics submenu, scroll to D14 Printhead Cont." and press Enter. Diagnostics D14 Printhead Cont. 2 The following message is displayed on the frontĆpanel: PH addr: # Cyan PS: # 3 Use the Up and Down arrow keys to show the values of the different colors. The values shown on the frontĆpanel for all Printheads should be 0. If a different value is shown then that Printhead has a continuity problem. Try the following to solve the problem: 1 DO NOT replace any parts. This will cause extra problems. Remove the Printheads and clean the flex contacts on the Carriage and the Printheads. Reseat the Printheads and try the test again. 2 Even if one of the Printheads failed the Printhead Continuity test, you must remove all the Printheads from the Carriage and try installing them one by one. Before installing each Printhead, check the continuity of all four Printheads. The frontĆpanel should display a 3ffff / 3fff result for each Printhead that is not inserted and the original values (the value that was displayed before the Printhead was removed) for the Printheads when they are inserted. If you get a value that is different than 3ffff / 3fff when the Printheads are removed then you must perform step 1 again. If you get the same results after repeating step 1, then the carriage is damaged. Replace the Carriage Assembly ' page 8Ć42. When you insert each Printhead, the values should change only for that Printhead. If the values of other Printheads also change, then the problem is the Printhead itself and not the actual Printer. In this case you must replace the complete Ink Delivery System of the color that failed. 3 If you continue getting the original value (the value that was displayed before the Printhead was first removed) then you must replace the complete Ink Delivery System of the color that failed and try the test again. 4 As a last resort, replace the Carriage Assembly ' page 8Ć42. 4 Press Previous when you have completed the test. The D1400 Done" message is displayed on the frontĆpanel if the test exits correctly. Service Tests HP DesignJet CP Series Printers 4-27