Lexmark T620 Service Manual - Page 172

4069-5XX/7XX Diagnostic Mode To enter the Diagnostic Mode: 1. Turn the printer off. 2. Press and hold the Go and Return buttons. 3. Turn the printer on. 4. Release the buttons when "Performing Self Test" displays on the operator panel. Exiting the Diagnostics Mode Select Exit Diagnostics to exit the Diagnostics Mode and return to normal mode. Device Tests Quick Disk Test This test performs a non-destructive read/write on one block per track on the disk. The test reads one block on each track, saves the data, and proceeds to write and read four test patterns to the bytes in the block. If the block is good, the saved data is written back to the disk. To run the Quick Disk Test: 1. Select the Quick Disk Test from the Device Tests menu. - The power indicator blinks while the test is in progress. - "Quick Disk Test/Test Passed" message displays if the test passes and the power indicator turns on solid. - "Quick Disk Test/Test Failed" message displays if the test failed and the power indicator turns on solid. 2. Press Go, Return, or Stop to return to the Device Tests menu. Disk Test/Clean WARNING: This test destroys all data on the disk and should not be attempted on a good disk. Also note that this test may run approximately 1 1/2 hours depending on the disk size. 3-6 Service Manual