Diagnosing invalid response code errors on card terminals. Safe handling, cable inspection, and software troubleshooting steps provided.
Provides a more granular view of the problem's origin.
Identifies potential physical or software causes.
Helps narrow down communication troubleshooting steps.
Invalid response codes typically originate from communication failures between the terminal and the payment processor. This can be due to voltage fluctuations, baud rate mismatches, signal attenuation in communication lines, or software errors within the terminal's communication protocols. EMV and NFC transactions are particularly sensitive to timing and data integrity.
The card terminal displays an "Invalid Response Code" error during transaction processing.
Avoid forcing cables into connectors. Do not use excessive force when cleaning the terminal. Ensure the terminal is placed on a stable and dry surface. In winter, be mindful of ESD from clothing or contact with metal objects before touching the terminal. NEVER attempt to open the terminal's casing due to potential anti-tamper mechanisms and electric shock hazards.
Regularly inspect communication cables for damage and ensure they are properly secured. Clean the terminal's exterior with a dry, antistatic cloth to prevent dust buildup and ESD. Implement cable strain relief measures to prevent cable damage. Keep the terminal's software updated with the latest patches.
If the terminal uses a physical phone line, check the line voltage with a multimeter. Low voltage can indicate a line fault. Also, try a different Ethernet port on the network switch, as some ports may have configuration or hardware issues. Note the exact error message/code for support.