HP 450c Service Manual - Page 48

Line Sensor Test Failure If the Line Sensor test fails, to resolve the problem, try one of the following: 1 Line sensor incorrectly calibrated: The accuracy calibration includes calibration of the line sensor on the carriage. You must use HP Matte film when performing the accuracy calibration (Details ' Chapter 5). Otherwise the line sensor will have problems loading some types of media. 2 Check and if necessary replace the Trailing Cable ' page 8Ć8. 3 Replace the Carriage Assembly ' page 8Ć37. 4 Replace the Electronics Module ' page 8Ć13. Only replace one component at a time and perform the test again before replacing another component. Using this procedure you will be able to determine exactly which component failed. Analog Multiplexer Test Failure If the Analog Multiplexer test fails, to resolve the problem, try one of the following: 1 Check and if necessary replace the Trailing Cable ' page 8Ć8. 2 Replace the Carriage Assembly ' page 8Ć37. 3 Replace the Electronics Module ' page 8Ć13. Only replace one component at a time and perform the test again before replacing another component. Using this procedure you will be able to determine exactly which component failed. 4-14 HP DesignJet 430, 450C and 455CA Printers Service Tests