Try one or more of the following:
Note: If the printer finds a tray that has the correct size and type of paper, then it feeds from that tray. If the printer cannot find a tray that has the correct size and type of paper, then it prints from the default paper source.
Here are troubleshooting steps for a ‘121.xx’ Service Fuser Error (except for 121.02. 121.16, 121.41 and 126.01).