Lexmark C720 Service Manual - Page 195

5024-001 If single is selected, no buttons are active during printing. If continuous is selected, return or stop can be selected to cancel the test. Note: The power indicator blinks while the page is printing. Check each test page from each source to assist in print quality and paper feed problems. Hardware Tests The following hardware tests can be selected from this menu: LCD Test DRAM Memory Test Parallel Wrap (if available) Serial 1 Wrap (if available) Serial 3 Wrap (if available) Button Test ROM Memory Test Serial Wrap (if available) Serial 2 Wrap (if available) LCD Test To run the LCD test: 1. Select LCD Test from the diagnostic menu. The LCD test continually executes the LCD display test. 2. Press Return/Stop to cancel the test. Button Test To run the button test: 1. Select Button Test from the diagnostic menu. With no buttons pressed, several OP (Open) appear on the display. 2. Press each button one at a time and a CL (Closed) displays in place of an OP. The proper operation of each button can be checked. 3. Press Return/Stop to cancel the test. Diagnostic Aids 3-9