If you own a Canon printer with an operational panel (panel with buttons and LCD screen), I am quite sure you often come across the 1240 error.
Canon recommends its users to lift the operational panel and pull the output tray out while printing documents. So, trying to print without doing the needful may trigger this error on your printer.
In most cases, the error can be easily fixed by following the directions on the printer screen—by lifting the operation panel up and pulling the output tray out. If that does not work, you can bypass this error by removing the operational panel detection sensor from your printer.
Follow the Instructions on the Printer Screen
Oftentimes, you can solve the 1240 error on your Canon printer by following the instructions on the screen. Simply lift the operational panel, pull out the output tray, and the error should go away.
While the printer is still powered on, hold the operational panel and lift it up until it is parallel to the printer’s body. You will hear a click sound once the panel gets up correctly.
Now hold the output tray and pull it completely outside. If you do not fully pull out the output tray, you may get a “1259 output tray error.”
Lift the paper support on the edge of the output tray.
Raise the support extension too.
Tap OK on the printer’s screen.
If the error persists, try restarting your printer and repeat the process again.
Clean the Sensor
On your Canon printer, there lies a small sensor in the form of a plastic lever just below the operational panel. It generally lies in the left part of the panel and is white in color. This sensor helps to detect whether or not the operational panel is opened.
Sometimes, this sensor can get clogged due to paper dust and fails to detect the position of the panel correctly. As such, you might face the 1240 error even when the operational panel is opened.
I recommend you look underneath the operational panel and clean the sensor area with a soft lint-free cloth. Make sure there are no foreign bodies interrupting the movement of the sensor.
You can move the operational panel up and down quite a few times to make sure it’s moving freely. The lever should be attached to the operational panel when it is opened.
Remove the Sensor to Bypass the 1240 Error
By now, I hope that you have already fixed the 1240 error on your printer. But don’t give up if you haven’t fixed it yet! I still got your back.
I will now discuss how you can bypass the 1240 error and print without issues, even when the operational panel is closed. It will also be helpful if the sensor has malfunctioned and the printer is displaying the false 1240 error.
Lift up the operation panel and access the lever.
Use an X-Acto knife and remove the lever from the printer. You may also use a household knife to get it off the printer. Be careful not to scratch the printer or hurt your hands.
Close the operation panel now and press the OK button on the printer’s screen.
You can then print normally without lifting the operational panel.
Caution: Proceed with this method only if you are printing on plain papers. Printing on thicker papers with the operational panel closed may cause paper jams on your printer. You may further damage the printer while removing the sensor from the printer, ultimately voiding its warranty. Proceed at your own risk.
If anything doesn’t seem to work, consult a printer professional or get in touch with Canon Support for assistance.