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M400 Pinpad showing Failure After Pin

Check DUKPT debit key status to resolve “Failure After Pin” or “No Key Loaded” on M400 pinpads.

Symptoms

  • Debit sale fails after PIN entry. The Pinpad shows “Failure”.

  • The Pinpad shows “No Key Loaded”.

Likely cause

The device may be missing the debit encryption key (DUKPT).

Do not add or attempt to load encryption keys yourself. If a key is missing, contact a VASC Technician or the Helpdesk.

Check if the debit key (DUKPT 0) is present on your Pinpad

1

Enter System Mode

On the M400 Pinpad, press and hold 1, 5, 9 at the same time for 5 seconds. Wait about 30 seconds for the menu to appear.

  1. Select Supervisor.

  2. Enter password 1668321.

  3. Press Enter (green key).

Press 1 5 9 as shown on this screenshot
Supervisor screen on pinpad
2

Open key status

Go to: Security → Key Status → DUKPT. You’ll see DUKPT 0, DUKPT 1, and DUKPT 2.

3

Check DUKPT 0

Check DUKPT 0.

  • If Empty / no key: the debit key is missing.

    • Next: Contact a VASC Technician to load the Debit encryption key.

  • Key present: the failure has another cause.

    • Next: Reboot the Pinpad and retry the debit sale. If it still fails, contact the Helpdesk.

Next actions

If DUKPT 0 is empty

Contact a VASC Technician to load the Debit encryption key.

If DUKPT 0 shows a key

Reboot the Pinpad and retry the debit sale. If it still fails, contact the Helpdesk:

Need assistance? Contact Verifone Helpdesk at anytime.

  • Use our Chat platform

  • Or call 1.800.VERIFONE (837.4366)

Tell us the troubleshooting steps you’ve already tried. This saves time and gets you the right support faster.

Also check basic connectivity in General Pinpad Troubleshooting.

To return to the Welcome screen (Reboot)

  1. Tap the Home icon.

  2. Select Reboot.

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