DIAGNOSIS The scanner carriage is stuck or has jumped its track, often due to an obstruction or a hard impact on the glass.
FIX Manually free the scanner carriage.
1. Unplug the printer from the wall.
2. Open the document cover (the flatbed lid).
3. Look at the white bar under the glass on the right side—that's the scanner carriage.
4. Gently nudge it with your fingers from side to side along its track. It should move smoothly from the center to the right edge.
5. Once it's moving freely, center it roughly under the glass. Plug the printer back in and power it on. The carriage should auto-home.
IF THAT DIDN'T WORK If the carriage is physically off its track or a plastic piece is broken, it needs disassembly. This isn't a user-serviceable part. You'll need to contact Epson support for a flatbed unit replacement.
HEADS UP Never place heavy objects on the closed document cover and avoid slamming it shut. The mechanism is delicate. If you frequently scan thick books, consider a dedicated sheetfed scanner.