f927eafa__Printer_Warning_Light_Flashes__Action
[Number of flashes/Cause] Three flashes: Front Tray or Front Feed Support is closed./Paper jams. [Action] 
If the Front Tray is closed, open it. The printer resumes printing. If the Front Feed Support is closed when printing from the Front Tray, open it and press the RESUME/CANCEL button on the printer. If the error still remains when the Front Tray or the Front Feed Support is opened, paper may be jammed. Remove the jammed paper, reload paper in the printer, and then press the RESUME/CANCEL button.
The Meaning of Canon Printer Warning Light Flashes
Action