There are several possible reasons why a scanner may not produce accurate scans.
First, a scanner may be outdated or poorly calibrated. Check to see if the scanner is properly calibrated and that it is running the most up-to-date scanning software. If not, update accordingly.
Second, the image format being scanned may be too complex for the scanner to accurately interpret. Different scanners have different capabilities when it comes to scanning certain types of files. Try using a simpler format, such as a JPEG or a GIF, and see if that improves the accuracy of your scans.
Third, the document being scanned may be too big or too small for the scanner, causing it to misinterpret details. Make sure the document fits within the boundries of the scanner glass, with at least an inch of space on either side.
Fourth, the quality of the original document may be too low for the scanner to correctly process. This could be caused by wrinkles, fading, or accidental dirt on the document. Make sure any documents you are scanning are free of blemishes or tears, and check the settings of your scanner to ensure the best possible scan quality.
Finally, make sure the scanner is clean and free from dust, as this can disrupt the scanning process. Clean the scanner glass and all associated components with a microfiber cloth and compressed air to remove any debris.
By troubleshooting these common issues, you should be able to restore your scanner to accurate scanning operations.