Troubleshooting 'Invalid Card Number' errors on magnetic stripe readers. Focus: cable integrity, ESD prevention, cleaning, and external diagnostic checks.
This can indicate a cable fault or connection problem.
Low humidity can increase the risk of ESD.
New devices can be a source of EMI.
Magnetic stripe readers decode data by detecting changes in magnetic flux as the card is swiped. The reader head contains coils that generate electrical signals corresponding to the encoded data on the magnetic stripe. Signal attenuation, head contamination, or incorrect baud rates can lead to misinterpretation of the data, resulting in an 'Invalid Card Number' error. External electromagnetic interference (EMI) and electrostatic discharge (ESD) can also corrupt the signal.
The magnetic stripe reader consistently returns an 'Invalid Card Number' error when processing cards with valid magnetic stripes. This occurs despite proper card swiping technique.
To prevent electrical shock or damage to equipment, ensure the card reader is safely handled by unplugging it from the power source or host device before performing any cleaning or maintenance. Avoid using excessive force when cleaning the magnetic read head. Do not use conductive cleaning solutions. Do not open the card reader casing; it contains anti-tamper mechanisms that will be triggered, permanently disabling the device.
Regularly clean the magnetic read head with a cleaning card (weekly or more frequently in high-traffic environments).,Ensure the reader cable is properly routed and secured to prevent strain and damage.,Implement ESD prevention measures, especially during dry seasons (e.g., anti-static mats, grounding straps).,Keep the area around the card reader free of dust and debris.,Periodically check and tighten cable connections.
Sometimes, a specific combination of keys pressed during the card swipe (e.g., holding down the 'Shift' key) can temporarily reset the reader's internal buffer. Consult the device documentation for specific key combinations. External ferrite chokes clamped on the reader's cable can mitigate EMI.