HP Designjet 2800/3800cp Service Manual - Page 164

PQ Problem: Missing/ Light Blocks of color in a print Printheads Affected: All Problem Description: Small well defined areas of light color, 0.4 inches tall, with a 4mm half-colored region on either side. Corrective Action: Solution will be different depending on the type of problem: 1 Cover opened, or cover sensor not making good contact. If the user is present, usually a "Close Window to Continue" message will show on the front-panel if this is happening, or the printer's carriage will be slowing down in the middle of a printing pass. D Solution - Check that covers are all shut. Wiggle covers with printer idle to see if this triggers any front panel messages. If so, the cover sensors need adjustment. 2 Intermittent opens/shorts in printhead. Printhead is shorting, probably due to ink in the electrical contacts. As the liquid short heats up, it may dry out and the printhead will start functioning properly again. D Solution - Check printer carriage and printhead electrical contacts for dried ink. Clean if dirty. If printhead still fails with clean contacts, replace IDS. 3 Broken trace in carriage trailing cable. D Solution - Replace the Trailing Cable or the Carriage Assembly. 6-22 HP DesignJet CP Series Printers Image Quality