> For the complete documentation index, see [llms.txt](https://commanderhelp.verifone.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://commanderhelp.verifone.com/customer-documentation/petro-and-c-store/pin-pads/implementation-guides/m425a/troubleshooting.md).

# Troubleshooting

## Troubleshooting

The M425A contains no user-serviceable parts. Do not open or disassemble the terminal.

{% hint style="warning" %}
Use only an approved Verifone power supply. Incorrect power ratings can damage the terminal.
{% endhint %}

| Symptom                    | What to check                                                                | If it persists            |
| -------------------------- | ---------------------------------------------------------------------------- | ------------------------- |
| Terminal does not power on | Confirm the power cable is secure and connected to a dedicated outlet.       | Contact Verifone support. |
| Screen is blank or dark    | Tap the display. Check the power and cable connections.                      | Contact Verifone support. |
| Display is unreadable      | Check every cable connection.                                                | Contact Verifone support. |
| Keypad does not respond    | Confirm the display shows the expected prompt. Try another transaction step. | Contact Verifone support. |
| Chip card read errors      | Test multiple cards. Confirm the chip is inserted correctly.                 | Contact Verifone support. |
| Magnetic-stripe failures   | Test another card and swipe smoothly at an even speed.                       | Contact Verifone support. |
| Contactless payment fails  | Hold the card or phone near the contactless symbol. Unlock the phone first.  | Contact Verifone support. |
| Network connection fails   | Check Ethernet, Wi-Fi range, and network availability.                       | Contact Verifone support. |

### Reader checks

#### Magnetic-stripe reader

1. Test a transaction with more than one card.
2. Confirm each card is swiped correctly.
3. Attempt a manual entry when your payment application permits it.
4. Contact Verifone if the issue continues.

#### Smart-card reader

1. Test several smart cards.
2. Confirm each card is inserted correctly.
3. Confirm MSAM cards are fully inserted and secured.
4. Contact Verifone if the issue continues.

### Tampering or damage

Remove the terminal from service immediately if you see damaged tamper labels, casing changes, inserted foreign objects, protruding wires, keypad overlays, or a tamper warning.

Keep the terminal available for investigation. Notify your company security officer and Verifone service provider.

### Contact support

Have the terminal serial number and displayed error message ready. The serial number is printed on the terminal label. A photo of the error message can speed diagnosis.


---

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