HP 450c Service Manual - Page 15

What can I do if the Printer continuously rejects Cartridges? If you are in Service Mode 1, the cover sensor is disabled. In order to test a new Cartridge set, the Printer must be powered OF and and ON again. 1 Remove tape and align cartridges: One frequent cause of cartridge problems is that the user has forgotten to remove the tape from new cartridges. Remove the tape. 2 Dirty pads: The connection between the carriage PCA and the cartridge flex connector is made by means of a gold bubble on the flex connector that touches a gold pad on the PCA. The Carriage Test (details ' page 4Ć12) includes a test of this connection. When nozzle failures occur, clean the flex contacts on the cartridge and in the Carriage. 3 Continuity Problem: Remove all the cartridges from the Carriage and try installing just the rejected cartridge. If the cartridge is still rejected then replace the cartridge with a new one. If the new cartridge is not rejected then check, one by one, if the other cartridges are rejected or not. 4 Faulty cartridge: Some black cartridges (51640A) with USE BEFORE dates of April '96 and earlier may have thinĆfilm damage. This means that the material used for channeling ink behind the nozzles can crack with aging. When this happens, ink seepage may cause many nozzles to fail (eight or more). Replace the black cartridge with one with USE BEFORE date of May '96 or later. 5 If the Cartridges are not inserted correctly into the Carriage, the Cartridges will be rejected. Make sure that the springs that hold the Cartridges in the Carriage are not broken or misplaced. 6 Perform the Carriage Test ' page 4Ć12. 7 Replace the Trailing Cable ' page 8Ć8. 8 Replace the Carriage Assembly ' page 8Ć37. Troubleshooting HP DesignJet 430, 450C and 455CA Printers 1-5