When a scan stops before it finishes, first check the scanner and its connection, then retry from a Mac scanning app such as Preview or Image Capture. If the scan still fails, narrow down whether the problem follows the app, connection, or scanner setup before removing and adding the device again. These steps apply to a scanner or multifunction printer connected to a Mac; device-specific screens can vary.

1. Check the scanner and connection

Confirm the scanner is powered on, plugged into an outlet, and connected securely. For a USB scanner, reconnect the cable directly to the Mac if possible. Apple specifically recommends connecting a scanner to the Mac’s USB port if it is currently connected through an AirPort base station. For a network scanner, make sure the Mac and scanner are still on the same network and that the scanner is available. Apple’s scanning troubleshooting guide lists power and cable checks among its first steps.

If the scanner’s own display shows an error, or it stops moving before the Mac reports a problem, check the device’s paper path, feeder, and status lights using the manufacturer’s instructions. Apple’s general Mac guidance does not document a universal scanner reset or a single command to clear a stalled scan; controls and recovery steps depend on the model.

2. Retry from a different Mac app

If you started the scan with the scanner’s physical button, try launching the scan from an app instead. Apple recommends Image Capture or Preview as alternatives. This helps determine whether the failure is tied to the scanner’s button workflow or also happens in a Mac app. Apple’s scanner troubleshooting steps

In Preview, choose File > Import from Scanner > [your scanner]. If it appears, start with a small test, such as one page on the flatbed or one sheet in the document feeder. Preview offers a Show Details button for scanning options, and its guide notes that feeder pages scan one at a time. If you are scanning many pages, a short test can help identify whether the interruption occurs immediately or only during a longer job. Apple’s Preview scanning guide

You can also open Image Capture, select the scanner under Devices or Shared, and start a scan. If the test works in one app but not another, the difference points toward that app’s workflow or settings; it does not by itself establish the cause. Image Capture supports scanning with a flatbed or an automatic document feeder, subject to the scanner’s capabilities. Apple’s Image Capture guide

3. Check whether macOS still recognizes the scanner

Open Apple menu > System Settings > Printers & Scanners. If the scanner is missing, choose Add Printer, Scanner, or Fax, then select it if it appears. Apple advises checking with the scanner manufacturer for current software for the model and consulting its documentation if it does not appear in the list. A multifunction printer that is already set up may expose its scanner without separate setup. Apple’s scanner setup guide

If the scanner was available before but has disappeared, Apple suggests removing the scanner or multifunction printer from the device list and adding it again. Try this after checking the connection and confirming the scanner is powered on. Re-adding it can restore its listing, but it will not fix a hardware issue or an unsupported model.

4. Retry after isolating the login session

If more than one user is currently logged in to the Mac, Apple recommends logging out all users, signing back in, and trying again. This is a specific troubleshooting step for the multiple-user situation; it is not necessary to change accounts when only one user is logged in. Apple’s scanning troubleshooting guide

When to contact the manufacturer

If scans still stop midway across Preview and Image Capture, after checking connections and trying a short scan, consult the scanner maker’s support for model-specific software and error steps. Record the app used, whether the scanner is USB or network connected, when the job stops, and any message displayed. Those details help distinguish a Mac setup problem from a device-specific fault without relying on undocumented reset commands.

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