Paper won't feed - Canon Pixma MP500 All-In-One InkJet Printer

Inside of the machine is dirty.
If the inside of the machine is dirty, the printed paper may be smudged.
Follow the steps described below to clean the inside of the machine.
1. Ensure that the machine is turned on and there is no paper loaded in the Auto Sheet Feeder.
2. Place A4/Letter-sized plain paper in landscape orientation, horizontally fold it in half.
3. Unfold the paper, and load the paper in the Auto Sheet Feeder with the inverted-V edge down.

4. Select <Bottom plate cleaning> from <Maintenance>.
5. Select <Yes> on the Bottom plate cleaning confirmation screen and then press [OK].
Paper will be ejected.
If protrusions inside the machine are stained, wipe ink off the protrusions using a swab or such like.
* Important
Before cleaning, be sure to turn OFF the machine.
Paper feed roller is dirty.
Follow the steps described below to clean the paper feed rollers.
1. Ensure that the machine is turned ON and there is no paper loaded in the machine.
2. Select <Roller cleaning> from <Maintenance>.
3. Select <Yes> on the Roller cleaning confirmation screen and then press [OK].
The paper feed roller will rotate as it cleans.
4. Repeat this operation twice.
5. Load three or more sheets of A4/Letter-sized plain paper lengthways in the Auto Sheet Feeder.
6. Select <Roller cleaning> from <Maintenance>.
7. Select <Yes> on the Roller cleaning confirmation screen and then press [OK].
The paper that is loaded in the machine will feed through the machine and be ejected.
8. Repeat Steps 5 to 7 three times.
Inappropriate paper type is used.
Check to see if the paper you are printing on is too thick. See Paper Types You Cannot Use.
Note that smudging may occur at the top and bottom edges of the paper when using Borderless Printing. Ensure that the paper you are using is compatible with Borderless Printing.
Thick paper is used.
When printing on thick paper, set the Paper Thickness Lever to the right.
This widens the gap between the FINE Cartridge and the paper. Try this maneuver if the printed surface is scratched.
Media is curled.
If all four corners or the printing surface of the paper is curled, the paper may become dirty or may not feed properly. Use the paper after correcting paper curl as follows.
1. Place the printing surface face up (A), and cover it with a sheet of non-printing regular paper to avoid damaging the surface.
2. Roll up the paper in the direction opposite to the paper curl as per the figure below.
3. Check the printing paper to confirm if the paper curl is eliminated to within approximately 2 to 5mm / 0.08 to 0.2 in (B).
It is recommended to print on curl-corrected paper one sheet at a time.
The media type is not selected correctly in the printer driver.
On the [Main] tab of the printer driver, ensure that the [Media Type] selected matches the paper loaded.

In the [Print] dialog box of the printer driver, select [Quality & Media] from the pop-up menu, and then ensure that the [Media Type] selected matches the paper loaded.
Paper is loaded incorrectly.
Load in the portrait orientation regardless of the print direction of the Auto Sheet Feeder.
Ensure that paper is loaded correctly. Slide the paper guides against the paper stack.