5 flashes indicates a faulty printhead or possibly a problem with the p/head contacts. Try removing the head which is easier if you take the cartridges out first(no tools required) and re-seat it having checked the contacts for dirt.|
If that doesn't work it may be that the waste ink tank is full. Try this ...
Canon S9000, S300, S400, i550, i560, i850, i860, i865, i9100, i9950, PIXMA iP3000 above,
1. Turn off printer
2. Hold down Resume button and press Power button.
3. Keep holding down Power button and let Resume button go.
4. Press Resume button 2 times then let BOTH buttons go.
5. Green lights will flash and then stop blinking.
6. When green lights are solid, press the Resume button 4 times.
7. Press the Power button and the printer should turn off, if not, press the Power button once more.
8. Your printer should respond as normal.