Symptoms
- Scanner beeps but shows an error or no match
- Red light shows but nothing registers
- Works on some barcodes but not others
Likely causes
- CommonDirty or scratched scanning lensDust or fingerprints on the lens can block accurate reading.
- CommonWrong scanning distance or angleMost scanners need to be held within a specific distance and fairly straight on.
- PossibleBarcode symbology not enabled in settingsSome scanners need specific barcode types enabled to recognize them.
- PossibleDamaged or low-quality printed barcodeA smudged, torn, or low-contrast barcode can be unreadable regardless of scanner health.
- Less commonLow battery on a wireless scannerWeak power can reduce scan range and reliability.
What to do
- Clean the scanning window with a soft, lint-free cloth.
- Hold the scanner at the recommended distance and angle from the barcode.
- Test on a barcode you know is undamaged and high quality.
- Check the scanner's configuration guide for enabling the barcode type you're using.
- Charge or replace batteries if it's a wireless model.
- Restart or reset the scanner to factory defaults if it seems misconfigured.
- Try scanning the same code with a phone barcode app to rule out a damaged label.
Tools and parts
- Soft cloth
When to call a pro
If a clean scanner still can't read a known-good, undamaged barcode, the scanning module has likely failed and needs professional repair or replacement.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.