Troubleshooting a Credit Card Terminal

by Keith Evans; Updated September 26, 2017

Credit-card terminals allow merchants to enhance their business and serve more customers by accepting credit-card payments, but do occasionally encounter problems. Whether the terminal is not reading cards, not printing, or simply not working, a few simple troubleshooting steps can help merchants quickly bring their terminals back to life.

Card Reading Errors

When a credit-card terminal reads a credit card, it employs a pair of magnetic sensors to pick up and decode data stored in thousands of microscopic magnets in the card’s stripe. If the terminal becomes unable to accurately read the card, the inability to discern this crucial data may cause errors. Merchants experiencing difficulty may try cleaning the card reader by wrapping a fresh, crisp dollar bill around a credit card and sliding it through the terminal; the rough texture of the currency can act as an abrasive agent to clean dirty magnetic readers, facilitating more effective card-reading. If the terminal still refuses to read credit cards, and the cards can be read on other machines, the terminal may need new magnetic readers installed.

Data Input Errors

If the terminal reads credit cards but does not allow additional data to be entered, or if entering additional data frequently results in errors, the terminal’s keys may be sticking. Long-term use, coupled with natural dust and other contaminates that work their way inside the terminal, can gum up keys and cause them to stick, resulting in difficulty entering data or using the terminal. Commercially available keyboard cleaner can help, as can a thorough cleaning of the outside of the terminal.

Printer Troubles

Many terminals send transaction and receipt output to an attached printer, but these relatively simple machines can occasionally fail and leave merchants and customers without printed records. If the printer fails to print, merchants should first verify that the “Power” light is illuminated and not flashing; if the light is flashing, there may be a paper jam that requires removing the print cover and any errant paper. If the “Power” light is not illuminated, merchants should verify that the printer is securely plugged into an electrical outlet and turned on; if the light still does not illuminate, and the power outlet is confirmed to be working, a new printer may be required. Finally, if the printer appears to be functioning normally but is not printing output from the terminal, merchants should verify that the cable connecting the terminal and printer is securely connected; even if the cable appears to be snug, reseating it by unplugging and reconnecting each end may resolve the trouble.

Complete Failures

Although credit-card terminals are fairly simple electronic devices, they do sometimes fail altogether. If the terminal illuminates and displays information on its screen, but does not otherwise function, the terminal provider or credit-card help desk may need to reprogram the machine using a special software download function. If no lights illuminate on the terminal, and the display does not contain any information at all, merchants should verify that the device is receiving power by plugging it into another outlet; if it still does not function, it may need to be replaced.

About the Author

Keith Evans has been writing professionally since 1994 and now works from his office outside of Orlando. He has written for various print and online publications and wrote the book, "Appearances: The Art of Class." Evans holds a Bachelor of Arts in organizational communication from Rollins College and is pursuing a Master of Business Administration in strategic leadership from Andrew Jackson University.