Lexmark T620 Service Manual - Page 86

4069-5XX/7XX Operator panel displays 260 Paper Jam immediately when envelope feed is requested - POST incomplete. FRU 1 Pass thru Sensor Action Check for any debris, pieces of envelope and so on over the pass thru sensor. Check for correct installation of the pass thru sensor flag. Make sure the sensor cable is attached to the envelope system board. Perform an envelope feeder sensor test to check both the sensor and sensor flag. Note: It may be necessary to use a small tool to actuate the sensor flag because it is located under the front cover. Be careful not to damage the flag. If the test fails, check the flag for any signs of damage or binds. If incorrect, replace the flag. If the flag is operating correctly, check the voltage at J3-3. The voltage measures approximately +5 V dc. If incorrect, replace the envelope system board. If correct, check the voltage at J3-2. The voltage changes from 0 to +5 V dc when the flag is moved in and out of the sensor. If incorrect, replace the sensor assembly. If this does not fix the problem, replace the envelope system board. 2-58 Service Manual