Lexmark C750 Service Manual - Page 166

5060-00x Operator panel LCD/status LED/buttons service check Use this service check to check both the operation of the panel buttons and to test the LCD display for correct operation. • Replace the operator panel assembly if the LCD display functions normally, but the LED does not come on. • If one or more of the operator panel buttons do not operate correctly, go to "Step A." If any of the following symptoms occur, go to "Step B" on page 2-132. • Operator panel LCD is blank/Power On/Status LED off • Operator panel LCD is blank/Power On/Status LED on • Operator panel LCD displays all diamonds/5 beeps/Power On/Status LED on Step A Step 1 Action and questions Buttons Test-perform the "Button Test" on page 3-19. Do any or all of the Buttons fail to operate correctly? Note: If all the buttons fail to operate correctly, the LCD display is blank, Power On Status LED is on, and the printer beeps 5 times, go step B. Yes Replace the operator panel. See "Operator panel removal" on page 4-46 No Test passes. No problem found Step B Note: Make sure the operator panel cable is seated firmly in J1 on the RIP board before proceeding with this step. Step 1 Action and questions LCD Test-perform the "LCD Test" on page 3-19. Can you run the test? 2 3 LCD Test-does the test pass? Operator panel-is the operator panel operating correctly except for a few pels missing or broken? Problem solved Replace the operator panel. See "Operator panel removal" on page 4-46 Go to step 6 Go to step 3 Go to step 4 Yes Go to step 2 No Go to step 4 4 Operator panel assembly-is the operator panel assembly completely blank and the power on status LED off? Operator panel assembly-is the operator panel assembly completely blank and the power on status LED on? Does the printer beep 5 times? Go to step 5 5 Go to step 10 Go to step 12 6 Go to step 7 Replace the operator panel. See "Operator panel removal" on page 4-46 2-132 Service Manual