Check the following two places again because it is easy to miss jammed paper in these locations.
- Look carefully in the duplexer by removing the duplex tray and pivoting the vertical duplexer portion away, then look in the lower rear portion (removing the 250 cassette will also help in improving visibility).
- Remove the black diverter (it has two white clothes pin type clips on it) and look into the exit of the fuser region (WARNING: it may be hot in this region) for a potential accordion style paper jam. After removing the jammed paper from the fuser region, put the black diverter back into position with the two white clothes pin type clips.