Lexmark C750 Service Manual - Page 200

5060-00x Drift Sensors This check is used to display the status of the thermal system used to compensate for printhead drift. The following screen is displayed when the test is selected: Com=aaaa C=cc Y= dd Values: If: Com= M=, C=, Y=, or K= Value: Err Good OP SH RA Number Description: RIP to A/D communication error Communication is good Open thermistor error Short thermistor error Range error Detected temperature in Celsius of last reading. Indicates the system is functioning properly. M=bb K=ee If Com=Err, replace the system board. See "System board" on page 4-80. If a number displays, or C, Y, or K=OP, or SH, check the following: 1. Check the cable of the appropriate thermistor (cyan, magenta, yellow, or black) to make sure it is installed correctly to the system board and to the thermistor board. If correct, go to step 2. 2. Check the continuity of the appropriate cable. Replace the cable if there is no continuity. If continuity is correct, go to step 3. 3. Replace the appropriate thermistor assembly. If this does not fix the problem, replace the system board. To exit the test, press Return or Stop. TOP FINE MAR ADJ Do not change this setting without consulting your next level of support. MISC TESTS Motor Detect This test initiates an Automated Motor Detection. It must be performed if the NVRAM contents are erased such as when a RIP or engine board has been replaced. This test must be performed anytime the ITU motor, Fuser motor, or Cartridge drive motors are replaced. To run the Miscellaneous Tests: 1. 2. 3. 4. Select Misc Tests from the Diagnostics Mode. Select Motor Detect. Remove all the print cartridges from the printer. Press Go. Motor Detection in progress is displayed: The test lasts approximately ten seconds. No buttons are active during detection and the test completes automatically. 3-16 Service Manual