the printer says 'out of paper' when the tray is clearly full, it just won't pick up any sheets.

Diagnosis

The "Out of Paper" error on the Canon PIXMA TS3520 is typically a false positive triggered by a failure in the mechanical pickup sequence. When you send a print job, the printer engages the pickup rollers to grab the top sheet; if the rollers slip or the paper doesn't move forward within a specific millisecond window, the internal sensor fails to detect a sheet entering the feed path. The printer then assumes the tray is empty, even if it is physically overflowing with paper. This is most commonly caused by "glazing" on the rubber pickup rollers—where a buildup of paper dust and ink residue creates a slick surface that cannot grip the page. It can also be caused by "curled" paper or a misalignment of the paper guides, which prevents the roller from making full contact with the center of the sheet. In some cases, a tiny scrap of paper from a previous jam may be blocking the sensor arm, tricking the printer into thinking the path is obstructed or empty.

How to Fix It

To resolve this, you need to restore the friction of the rollers and ensure the paper is feeding at the precise angle required by the TS3520's rear-feed tray.

1. Remove the entire stack of paper from the rear tray. Use a damp, lint-free microfiber cloth dipped in distilled water (do not use rubbing alcohol as it can dry out the rubber).
2. Locate the gray rubber pickup rollers at the base of the feed slot. Gently rotate the rollers with your finger while wiping them to remove the white paper dust and grime. Ensure the rubber feels "tacky" again.
3. Take your stack of paper and "fan" the edges to break any static cling between sheets. Tap the stack firmly on a flat table to ensure all edges are perfectly flush.
4. Slide the paper back into the tray, but do not overfill it. Ensure the stack is below the maximum fill line indicated on the tray wall.
5. Adjust the blue paper guides. Slide them snugly against the edges of the paper, but not so tight that the paper bows or arches. If the guides are too loose, the paper will feed at an angle and trigger the error.
6. Press the "Black" or "Color" button on the control panel to clear the error and restart the feed sequence.

If That Didn't Work

• Inspect for Foreign Objects: Use a bright flashlight to look deep into the rear feed slot. Even a small staple, paperclip, or a torn piece of a previous page can block the pickup roller from engaging. If you see a fragment, use a pair of tweezers to carefully pull it out in the direction of the paper path.
• Change Paper Weight: If you are using heavy cardstock or glossy photo paper, the TS3520 often struggles to grip these. Try switching to standard 20lb multipurpose office paper to see if the error persists. If standard paper works, your specialty paper is likely too thick or too smooth for the rollers.
• Hard Reset the Logic Board: Power off the printer and unplug the power cord from the wall outlet. Wait exactly 60 seconds. While unplugged, press and hold the power button for 15 seconds to discharge remaining electricity. Plug it back in and attempt to print.
• Check for Roller Wear: If the printer is several years old and the rubber on the rollers looks flat or cracked, the rollers may need replacement. You can temporarily improve grip by lightly scuffing the rubber surface with a piece of high-grit sandpaper (400 grit) to remove the glazed layer.

Heads Up

• Avoid using "cheap" recycled paper with high lint content, as this accelerates the buildup of dust on the rollers and leads to more frequent "Out of Paper" errors.
• Never push the paper stack too deep into the tray; it should sit comfortably against the backstop without being forced.
• Store your paper in a cool, dry place. Damp paper curls slightly, which prevents the TS3520's top-loading mechanism from grabbing the sheet effectively.
• Always use the paper guides to keep the stack centered; feeding paper off-center is the primary cause of skewed prints and false empty-tray alerts.