why is my canon pixma tr8620a making a loud grinding noise when it tries to print?

Diagnosis

The loud grinding noise in a Canon PIXMA TR8620a is typically caused by a mechanical failure in the carriage drive system or a critical obstruction in the paper feed path. When the printer attempts to move the print head assembly (the carriage) across the encoder strip, any physical blockage—such as a torn piece of paper, a fallen staple, or a buildup of dried ink—forces the stepper motor to skip teeth on the drive gear. This creates a harsh, rhythmic grinding sound as the motor continues to rotate while the carriage remains stationary. Alternatively, the noise may stem from the paper pickup rollers. If a foreign object is lodged in the rear tray or the cassette, the rollers will spin against the obstruction without gripping the paper, causing the plastic gears to chatter. To confirm the source, listen closely to whether the noise occurs immediately upon startup (carriage issue) or only once the print job begins and the rollers engage (feed issue). If the carriage is stuck at one end of the rail, it is almost certainly a carriage jam or a failed timing belt.

How to Fix It

1. Power down the printer completely and unplug the power cord from the wall outlet to prevent any electrical surges or accidental movement during the cleaning process.
2. Open the scanning unit/cover to expose the interior. Gently attempt to slide the print head carriage from one side to the other. If it resists, do not force it; instead, look for small scraps of paper lodged in the far left or right "parking" stations.
3. Inspect the encoder strip—the thin, transparent plastic ribbon that runs across the width of the printer behind the carriage. Use a dry, lint-free cloth to gently wipe any ink smudges or grease off this strip. A dirty strip causes the carriage to "hunt" for its position, leading to violent movements and grinding.
4. Open the rear cover and the bottom cassette. Use a flashlight to inspect the paper path for any foreign objects like paper clips, staples, or remnants of a previous paper jam. Use a pair of needle-nose pliers to remove any debris carefully.
5. Check the paper guides in the cassette; ensure they are snug against the paper stack but not so tight that they warp the paper, which can cause the rollers to struggle and grind.
6. Reconnect the power and perform a hard reset by holding the power button for 5 seconds, then unplugging for 30 seconds before restarting.

If That Didn't Work

• Lubricate the Carriage Rail: Over time, the factory grease on the metal guide rail can dry out or collect dust, creating friction that the motor cannot overcome. Apply a tiny amount of high-quality white lithium grease to the rail and manually slide the carriage back and forth to distribute the lubricant.
• Clear the Rear Feed Slot: If the grinding happens during paper intake, use a can of compressed air to blow out the rear feed slot. Small particles of dust or hair can get caught in the pickup rollers, causing them to slip and vibrate.
• Inspect the Timing Belt: Check the black rubber belt that moves the carriage. If you see any fraying or if the belt has jumped a tooth on the gear pulley, the carriage will be misaligned. If the belt is loose, the motor will spin without moving the carriage, producing a loud rattling sound.
• Reset the Encoder Disk: On the far left side of the printer, there is a circular plastic disk (the encoder disk). If this disk is coated in ink or grease, the printer cannot track the carriage position. Gently clean the disk with a cotton swab dipped in isopropyl alcohol.

Heads Up

• Never use oil or WD-40 on the internal rails; these attract dust and can degrade the plastic components of the TR8620a. Only use lithium-based grease.
• Avoid pulling paper out of the printer in the opposite direction of the feed path, as this can bend the delicate plastic pick-up fingers and lead to permanent grinding noises.
• Ensure you are using paper that meets the weight specifications for the TR8620a; excessively thick cardstock can put undue strain on the feed motors.
• Always keep the printer covered when not in use to prevent dust from settling on the encoder strip, which is the leading cause of carriage positioning errors.