Lexmark C750 Service Manual - Page 148

5060-00x Step 4 Actions and questions Unplug all cables from the system board, except J6, J35, J37. See "System board - non-network" on page 5-6 or "System board - network" on page 5-7. Does the printer power up and display a message? Yes Go to step 5 No Replace the "System board" on page 4-67. 5 Turn off the printer and plug in the cable for the component that is related to the error presented. For example, for the 114 Service Printhead error, plug in the black printhead J11 and J12. Use connector locations on "System board - non-network" on page 5-6 or "System board - network" on page 5-7. Repeat this step until the original DC power problem occurs. Does the DC power problem occur? Check the cable and component that was last connected to system board for a problem such as a short. If printer comes to Ready, connect the remaining cables and print. Autocompensator service check If the paper fails to feed from Tray 1 or 500-sheet option, go to "Step A" on page 2-114. If the autocompensator fails to lower when Tray 1 is installed, go to "Step B" on page 2-115. If the autocompensator fails to retract when you attempt to remove Tray 1, go to "Step C" on page 2-115. If there is no indication that the media is out or low, go to "Step D" on page 2-116. If the printer fails to detect transparencies and 203 Paper Jam appears, go to "Step E" on page 2-116. Note: When feeding paper through the printer to check for autocompensator problems, use the Tray 1 Feed test in the Diagnostics Menu. A printed copy is not required. Step A Step 1 Action and questions Use the tray 1 feed test to feed paper from tray 1. Check to see if the pick rolls are turning. Note: Observe the pick rolls by opening the Lower Jam access door assembly. Do the pick rolls turn? 2 Check the autocompensator pick rolls for contamination or damage to the rolls. Is there any excessive contamination or damage to the pick rolls? 3 Verify that the autocompensator is not stuck in the up position. Verify that the output clutch assembly is not damaged. Is the autocompensator stuck in the up position or the output clutch damaged? 4 Check the voltages at J73 on the engine board. Are the voltages correct? Replace the pick rolls. Always replace both pick rolls at the same time. Dislodge the autocompensator. If this does not fix the problem, go to step 4. Replace the autocompensator assembly. See "Autocompensat or pick assembly removal" on page 4-17. Go to step 3 Yes Go to step 2 No Go to step 3 Replace the engine board. See "Engine board removal" on page 4-29. Replace the engine board. See "Engine board removal" on page 4-29. 2-114 Service Manual