---
title: "The buttons on my P400 Plus card terminal aren’t working"
slug: "the-buttons-on-my-p400-plus-card-terminal-aren-t-working"
updated: 2026-06-16T13:00:51Z
published: 2026-06-16T18:16:39Z
canonical: "mysupport.roller.software/the-buttons-on-my-p400-plus-card-terminal-aren-t-working"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://mysupport.roller.software/llms.txt
> Use this file to discover all available pages before exploring further.

# The buttons on my P400 Plus card terminal aren’t working

## Problem

If your P400 Plus card terminal appears unresponsive, it might be due to a faulty keypad. Common causes for a faulty keypad include:

- The terminal was dropped or physically damaged.
- Dust, sand or debris is lodged under the keys.
- Water damage to the device.
- General wear and tear.

A faulty keypad makes it harder to take guest payments or access admin functions which can cause unnecessary delays at check-in or point of sale.

> [!NOTE]
> The Verifone P400 Plus is no longer sold for new orders after April 30, 2026, due to updated payment security standards. If you’re already using this terminal, you can continue to use it and it will remain supported until at least April 2029. [Learn more](/v1/docs/choose-and-order-roller-payments-terminals)

## Solution

If you’re having difficulties with the keypad, carefully clean the terminal while checking for signs of damage. Then run a diagnostic to confirm if the keypad is still working or if the terminal needs to be [replaced](/v1/docs/choose-and-order-roller-payments-terminals).

## Guidelines for cleaning your card terminal

Follow the guidelines below when cleaning a terminal to make sure you don't accidentally trigger the TAMPER alert. Triggering the TAMPER alert on the device makes it unable to be used.

- Don't vigorously scrub or shake the terminal.
- Don’t pour or spray any liquid, sanitizer, or disinfectant directly onto the terminal.
- Don’t use bleach, hydrogen peroxide, thinner, trichloroethylene, or ketone-based solvents. These substances can cause rubber and plastic to deteriorate.
- Don't vigorously rub the terminal with a dry towel or cloth. This can cause an electrostatic discharge and damage the device.
- Don't clean the smart card reader, this voids the warranty.
- Avoid touching the battery contact points.

## How to clean your card terminal

1. Power off the card terminal.
2. Disconnect the power cable from the terminal.
3. Slightly dampen a clean cloth with water.
4. Put a few drops of a cleaning solution on the dampened cloth. Don’t apply cleaner directly to the terminal.
5. Gently wipe the damp cloth over the keyboard and display.
6. Wipe the terminal with a clean dry cloth.
7. When the terminal is completely dry, reconnect it to the power cable and turn it on.

## Run diagnostics on the keypad

After cleaning the terminal and confirming there’s no external damage, run a diagnostic on the keypad to confirm if each key is working correctly:

1. Press **9 + Green** to open the **Settings** menu.
2. Scroll down and select **Diagnostics**.
3. Select **Keypad.**
4. Select the **blue arrow** button to start the test.
5. Press each individual key on the keypad.

> [!WARNING]
> If one of the keys is unresponsive, you will likely need to [order a replacement terminal](/v1/docs/choose-and-order-roller-payments-terminals).

## Learn more

- [ROLLER Payments card terminal troubleshooting](/v1/docs/troubleshoot-roller-payments-card-terminals)
- [Why does my ROLLER Payments terminal show a TAMPER error?](/v1/docs/why-does-my-roller-payments-card-terminal-show-a-tamper-error)

## Related

- [Install drivers for Worldpay (Vantiv) Lane 3000 USB card terminals](/install-drivers-for-worldpay-vantiv-lane-3000-usb-card-terminals.md)
- [The buttons on my V400m card terminal aren’t working](/the-buttons-on-my-v400m-card-terminal-aren-t-working.md)
- [Why does my ROLLER Payments card terminal show a TAMPER error?](/why-does-my-roller-payments-card-terminal-show-a-tamper-error.md)
- [Set up ROLLER Payments terminals](/set-up-roller-payments-terminals.md)
- [Choose and order ROLLER Payments terminals](/choose-and-order-roller-payments-terminals.md)