General Troubleshooting Solving Print Quality Problems Whenever a Print Quality problem appears, it is advisable to print the Diagnostic Print to help diagnose the problem. The Diagnostic Print will help you differentiate between possible printhead errors and other problems such as incorrect front-panel selection, driver or RIP configuration or mechanical problems. The Front Panel is blank 1 See What to do if the Front Panel is blank on page 2-3 . The Printer does not Power ON 1 Check that the power cord is connected correctly to the Printer and to the Power Socket. 2 Check that the Power Switch on the BACK of the Printer is in the ON position.
3 Check to see the LED on the Front Panel Power Switch are On. 4 Check that the Front-Panel Cable is correctly connected to the Electronics Module. Also make sure that the Front-Panel cable is not damaged. 5 Replace the Power Supply Unit. See Starwheel Assembly on page 6-208 . The Printer Continuously Rejects Printheads 1 Clean the flex contacts on the Printhead and in the Carriage Assembly using the Carriage Interconnect Wiper and try again. See Flex Contacts Cleaning Tool on page 3-20 . 2 If ALL the Printheads are rejected (the status message on the Front Panel does NOT show "OK" for ALL the Printheads) then perform the Electronic Module Test. See 3. Electronics Module on page 3-21 .
Cover Sensors are not Working 1 Perform the Sensors Test. See 5. Sensors on page 3-31 . 2 Check if the cable for the faulty sensor is not damaged and is connected correctly. 3 Replace the faulty Sensor. The Line Sensor has Problems Detecting Media 1 Check the type of media that is being used since the Line sensor may have problems detecting transparent media or some types of Non-HP media. Try loading white HP media in to the Printer and check if the Line sensor detects it. 2 The Line Sensor is not calibrated correctly. Perform the Line Sensor Calibration. See Line Sensor Calibration on page 4-15 . 3 The Line Sensor is damaged or faulty. Replace the Line Sensor.
See Line Sensor (T1120/T1120ps) on page 6-157 . HP Designjet T Series — Service Manual 1-5