Lexmark T620 Service Manual - Page 175

4069-5XX/7XX - The single Duplex Quick test cannot be canceled. The printer attempts to print the Quick Test Page from the default paper source. If the default paper source only supports envelopes, then the page is printed from Tray 1. Check the Quick Test Page for the correct offset between the placement of the first scan line on the front and back side of a duplexed sheet. If adjustment is necessary the Top Margin Offset must be adjusted first. The range of the adjustment is -25 to +25. The Duplex Top Margin Offset range is -20 to +20. Adjustment of this setting lets you shift up or down the position of the Top Margin. Changing this parameter by 1 unit moves the margin 1/100 inch. A positive offset moves the text down the page and widens the top margin while a negative offset moves the text up the page and narrows the top margin. 3. Press Return/Stop to exit the test. Check the Top Margin Offset of the base printer. Duplex Sensor Test This test is used to determine whether or not the Duplex sensors and switches are working correctly. Select Sensor Test from the Duplex Tests menu. Manually actuate each of the duplex sensors. When the sensor/ switch is closed, CL (closed) displays, when the sensor/switch is open, OP (Open) displays. Duplex input sensor Duplex exit sensor Press Return/Stop to exit the test. Duplex Motor Test This test lets you test the duplex unit paper feed drive system, and verify that the power and velocity values are acceptable. Diagnostic Aids 3-9