Garbled characters on the scanning device may be caused by many reasons. Here are some common solutions:

Check The Settings: 

Make sure the settings between the scanning device and the computer or related device are the same. In particular, the encoding format must be consistent.

Check whether the input method is set to English and Caps Lock is not turned on.

Check the Scanned Object: 

Make sure the scanned barcode or QR code is standard and not damaged or blurred.

If the scanning device cannot recognize the current object, you may need to change the scanning object or use another scanning device.

Check The Hardware: 

Clean the scan head of the scanning device to make sure it is not contaminated or damaged.

Check whether the connection cable between the scanning device and the computer is intact and the contact is good.

Update or Reinstall The Driver: 

Go to the official website of the QR code scanning device manufacturer, download and install the latest driver.

Make sure the driver installed in your computer matches the model of your scanning device.

Check the Window Parameter Properties:

If the problem occurs in a specific software (such as Excel), try a test scan in a text document.

If the text document is scanned normally, there may be a problem with some parameter attribute settings of the software window, and the attributes need to be modified to text.

Check The Computer System: 

Some QR code scanning devices may be more compatible with specific operating systems (such as Windows). Make sure the system you are using meets the requirements.

Check The Internal Settings of The Scanning Device: 

Check whether the prefix and suffix are set. This may cause garbled characters. Just restore the default settings.

If the scanning device supports the recovery barcode function, try to use the recovery barcode to recover.

Check The Content of The Scanned Barcode: 

If the barcode contains Chinese or other special language symbols, make sure the scanning device supports scanning these languages.

Some scanning devices may not be able to directly scan QR codes that contain barcode content other than alphanumeric characters, such as Italian, Korean, Vietnamese, Russian, etc. You need to confirm the function of the scanning device.