brother printer says 'paper jam' but i've opened everything and there's no paper stuck anywhere.

Diagnosis

Phantom paper jams on the Brother MFC-L2750DW typically occur when the printer's internal logic detects that a paper-path sensor flag has not returned to its "home" position within the allotted time. This isn't always caused by a full sheet of paper; more often, it is a tiny, millimeter-sized scrap of paper or a buildup of paper dust that is physically obstructing a plastic sensor lever. Because these flags are small, spring-loaded plastic tabs, they can either be pushed out of place by a jam or become "sticky" due to accumulated toner dust. Another common culprit is the registration roller or the pickup roller. If these rollers have become glazed or slippery, the printer attempts to pull a sheet, fails to move it past the first sensor within the timeout period, and triggers a "Paper Jam" error even though no paper is actually stuck. In some cases, the error is triggered by a misalignment of the drum unit or toner cartridge, which puts slight pressure on the internal chassis, preventing a sensor flag from flipping back to its neutral position.

How to Fix It

To clear a phantom jam, you must perform a deep mechanical reset of the paper path. Follow these steps precisely:

1. Power down the machine and unplug the AC power cord from the wall to discharge the capacitors and reset the sensor logic.
2. Open the rear jam clear cover (the flap on the back of the machine). Use a high-lumen flashlight to inspect the area around the fuser rollers. Look specifically for tiny white scraps of paper curled around the edges of the rollers.
3. Open the front cover and remove the TN760 toner cartridge and the DR760 drum unit assembly. Set them aside on a piece of scrap paper.
4. With the drum removed, look into the cavity. Locate the plastic "fingers" (sensor flags) along the paper path. Gently flick these flags with a toothpick or a dry cotton swab to ensure they spring back instantly. If they feel sluggish, clean them with a small amount of isopropyl alcohol.
5. Check the paper tray. Remove the tray entirely and look into the printer's belly for any stray pieces of paper or foreign objects (like staples or paper clips) that may have fallen into the pickup area.
6. Clean the pickup rollers. Use a lint-free cloth dampened with water or isopropyl alcohol to wipe the rubber rollers located at the bottom of the paper tray area. Rotate them manually to clean the entire circumference.
7. Reinstall the drum and toner, ensuring they "click" firmly into place. Close all covers and plug the unit back in.

If That Didn't Work

• Perform a Hard Reset: With the printer on, press the Menu button, navigate to General Setup, then Maintenance, and select Reset. Choose "All Settings" to clear any cached error states in the NVRAM that might be holding onto the jam notification.
• Check the Duplex Tray: Open the back cover and locate the duplexing mechanism. Sometimes a piece of paper is lodged in the reverse-path area, which is not visible from the front or the main rear flap. Gently push the duplex rollers in the direction of the paper flow to dislodge hidden debris.
• Inspect the Rear Paper Feed: If you were using the manual feed slot, check the narrow gap where the paper enters. A small tear in a sheet of heavy cardstock often gets lodged right at the entry point, keeping the manual feed sensor permanently triggered.
• Replace the Drum Unit: If the DR760 drum unit is leaking toner or is improperly seated, it can create mechanical friction that the printer interprets as a jam. Try printing with a different drum unit if available to rule out a chassis misalignment.

Heads Up

• Avoid using compressed air to blow out the printer; this often pushes tiny paper scraps deeper into the sensor housings, making phantom jams permanent.
• Never touch the shiny green or black rollers of the fuser unit with your bare fingers, as skin oils can cause future jams and streaks on your prints.
• Always fan your paper before loading it into the tray to prevent "double-feeding," which is the primary cause of the torn scraps that trigger these errors.
• If you use high-GSM cardstock, always use the manual feed slot rather than the main tray to prevent the registration rollers from slipping.