Nayax Card Reader Troubleshooting Guide for Vending Machines

Nayax Troubleshooting

Tired of Nayax Card Reader Issues? VTM Vending Has the Solution

Complete Nayax Error Codes and Troubleshooting Guide

VTM OEM Distributor of Nayax • MDB Level 3 Support

Are you constantly dealing with Nayax card reader errors?

M00, M01, V00, V01, V02, RSSI 99 authorization declined, sound familiar?

You swipe a card… nothing happens. No prompt. No transaction. Just frustration.

You troubleshoot, troubleshoot, troubleshoot…

Wait hours for a Nayax rep, if they call back. Cross your fingers, hope it gets fixed… Then the same problem happens all over again.

What's the real issue? What's the real solution?

VTM Vending is here to provide permanent solutions to your Nayax card reader issues. We go beyond troubleshooting, we identify the root causes and fix them for good!

As an OEM distributor of Nayax, VTM Vending doesn't just troubleshoot, we fix the problem at its core and provide permanent solutions.

We go beyond just telling you what's wrong, we explain why it's happening and how to prevent it for good.

If you are experiencing trouble with your AI smart cooler, ReyVend has an excellent guide on troubleshooting errors codes as it relates to smart cooler equipped with pre-authorization.

With Our Support, You'll Learn How To:

  • Assign payment IDs
  • Reset Parameters and Reload configuration files
  • Change Settings for your specific protocol (ie. MDB Level 3)
  • Add a payment kernel
  • Optimize your card reader for seamless transactions

We'll Also Guide You Through:

  • Locating and updating your firmware
  • Performing factory resets
  • Setting up unique, cloneable payment IDs for future machines

Smart Vending Starts Here

VTM Vending specializes in cashless payment solutions and advanced Nayax technical support. Whether you're facing recurring issues or setting up new machines, we are here to make your experience smooth and your cashless transactions stable.

Complete Nayax Error Codes and Troubleshooting Guide

Video Walkthrough

Problem: The Nayax card reader does not prompt for payment (it does nothing) and does not say "please insert your card".

Solution: Check MDB Settings change them if necessary and then perform a power cycle.

MDB Settings:

1. MDB Parameters: Ignore VMC Configuration: Enabled (ON)

2. MDB Flags: MDB Flags: 06 Ignore + Pre Selection

Overlooked cause, check this first: the product you selected costs more than the reader's maximum payment setting. The reader will not prompt for a card on a price above its limit, so it looks dead when it is actually declining the amount.

  • Quick test: select a cheaper product. If the reader prompts for payment on that one, the setting is your problem, not the hardware.
  • Fix: check the minimum and maximum transaction settings in the MoMa app, or call VTM tech support at (888) 373-8158 and we will change it for you.

V00: No Communication

Meaning: No communication between the machine and the Nayax device.

Solutions:

Cashless out of order error showing V00 machine on Nayax vending machine
  • Technician Mode: Enter Technician Mode on the card
     reader (password: 123123 or 8).
  • Factory Reset: Perform a factory reset via the reader menu.
  • Default Parameters Reset: Use the Nayax web application to reset default parameters.
  • Inspect Cables: Ensure MDB cables are securely connected and undamaged.
  • Contact Support: If unresolved, consult VTM Vending or Nayax support.

Basic Communication Troubleshooting:

  1. Power Off the Vending Machine
    • Locate the SIM card on the left side of the device.
    • Pull down the metal bracket, remove the SIM card, and reinsert it properly (cut corner on the upper side).
    • Ensure the SIM card slot is securely closed.
  2. Check the Antenna Connection
    • Unplug the antenna from its port and replug it firmly until you hear a "click."
    • Ensure the antenna is still positioned on top of the vending machine or as high as possible.
  3. Factory Reset the Device
    • Once the Nayax logo appears, press the menu button (three horizontal lines).
    • Select Technician Mode and enter the password 123123.
    • Scroll down and select FACTORY RESET.
    • The device will restart and should return to the tap/scan to pay screen.

If the issue persists: Try a Webbing SIM Card

  • If Verizon's coverage is still weak, switch to a Webbing SIM card ($2.50 + shipping via UPS).
  • Webbing SIM can connect to Verizon, AT&T, or T-Mobile, offering better reception in congested areas.

Use a High-Gain Antenna

  • If the signal does not improve with an AT&T/T-Mobile network switch, consider a high-gain antenna ($30 + shipping via UPS).
  • This is recommended for weak signal areas and requires secure installation on top of the vending machine.
Webbing Sim Card Streamlining Global Data ConnectivityVTM Vending Nayax high gain cellular antenna designed for enhanced connectivity in vending machine systems.

V01: MDB Configuration Issue

Meaning: MDB settings are misconfigured.

Solutions:

Cashless payment reader showing “Cashless out of order” with V01 machine fault and QR code on a Nayax device
  1. Access MDB Settings: Use the Nayax web portal to verify MDB settings.
  2. Select "06 Ignore Pre-Selection":
    • Save settings and initiate an update via the Update Queue.
  3. Restart Machine: Unplug the machine for 3 minutes, then reconnect power.
  4. Check Firmware: Update the vending machine and Nayax firmware.
  5. Contact Support: If unresolved, consult VTM Vending support.

V02: Cashless Payments Disabled

Meaning: The machine sent a "Reader Disable" command due to a communication issue.

Solutions:

  1. Restart the Machine: Power off for 3 minutes and then power back on.
  2. Enable Reader: Re-enable cashless functionality via the Nayax web application.
  3. Inspect SIM Card: Reseat the SIM card and verify proper installation.
  4. Contact Support: Contact VTM Vending Support for troubleshooting.

M01: MDB Device Not Responding

Meaning: The card reader cannot communicate with the vending machine controller.

Solutions:

  1. Check Connections: Inspect all MDB cables for secure connections and damage.M01 Nayax Error Code
  2. Restart Machine: Power cycle the vending machine.
  3. Configure MDB Settings: Use the Nayax portal to verify MDB Level 3 settings.
  4. Firmware Update: Update firmware on both the machine and the Nayax reader.
  5. Contact Support: Reach out to VTM Vending or Nayax support.

M02: Reader Disabled

Meaning: Communication is blocked due to an MDB misconfiguration.

Solutions:

M02 Nayax Error Code
  1. Enable Reader: Re-enable the reader in the Nayax portal.
  2. Power Cycle: Restart the machine to reset connections.
  3. Inspect Hardware: Check and reseat the MDB cable.
  4. Contact Support: Contact VTM Vending or Nayax support if the issue persists.

M05: No Server Connection

The device cannot establish a connection with the Nayax server.

Solution:

  1. Check the SIM Card:
    • Turn off the vending machine.
    • Open the Nayax terminal and remove the SIM card.
    • Wipe the contacts with a dry cloth.
    • Reinsert the SIM card and turn the machine back on.
  2. Check the Antenna & Signal Strength:
    • Ensure the antenna is securely connected.
    • Relocate the antenna to improve signal reception.
    • If damaged, replace the antenna.
  3. Restart the Nayax Terminal:
    • Access Technician Mode on the Nayax terminal.
    • Enter the password.
    • Scroll down and select Restart.
  4. Restart via the MoMa App:
    • Open the app and select the vending machine.
    • Go to Tasks and Warnings, select Actions, then Restart Device.

RSSI Signal Strength Issues or Cash Only Display

Indicator

  • 99 RSSI: No communication.
  • RSSI < 18: Poor signal strength.

Solutions:

  1. Enable Cashless: Verify that cashless settings are enabled in the Nayax portal.
  2. Hardware Check: Confirm all MDB and antenna connections are secure.
  3. Check Antenna: Ensure the antenna is securely connected to the reader.
  4. Check and reseat SIM card: Ensure that the SIM card is correctly inserted into the back of the device. Remove the SIM card and re-insert it. If possible, take a known working SIM card and see if this fixes the issue. Make sure it is like for like SIM, meaning: replace a Verizon SIM for Verizon (Verizon SIM card begins with 89148) and Non-Verizon SIM for Non-Verizon.
  5. Upgrade Antenna: Install a high-gain antenna if signal strength is weak or make sure the antenna is correctly connected to the antenna port. You may also move the antenna and relocate it to a high location outside the vending machine (ie. on top of the vending machine).
  6. Reboot the Device: Unplug the machine for 2 minutes and plug it back in and wait a few minutes for everything to reload. Test again.
  7. Monitor Signal: Use the Moma App or Nayax web portal to view RSSI history and fluctuations.
  8. Contact Support: If unresolved, VTM Vending can assist with carrier changes or SIM replacement.

General Troubleshooting for MDB Level 3 Vending Machines

Problem: The transaction goes through, but it is very slow.

Solution: This is almost always poor communication, not a settings problem. The reader is retrying over a weak cellular connection until the transaction finally clears.

  • Check RSSI: a signal reading near 99 means the reader has almost no connection. See the RSSI section above for how to read it.
  • Check the antenna: make sure the antenna cable is seated on the circuit board and the antenna pole is attached and undamaged.
  • Reboot the machine: power cycle the machine and let the reader reconnect. Slow transactions that clear up after a reboot confirm it was communication.

MDB (Multi-Drop Bus) Level 3

MDB (Multi-Drop Bus) Level 3 is a standard for communication between vending machines and peripherals. Here's how to maintain compatibility and performance:

  • Check Compatibility: Ensure both the vending machine and Nayax reader support MDB Level 3.
  • Verify Settings: Use the Nayax portal to confirm correct MDB configurations.
  • Inspect Physical Connections: Check MDB cables for proper installation and signs of damage.
  • Update Firmware: Regularly update firmware on both the vending machine and the Nayax device.
  • Monitor Error Logs: Use the Nayax web portal to view detailed error logs for diagnostics.
  • Perform Signal Tests: Regularly test RSSI signal strength using the Moma App or Nayax reader menu.

DEX Failed Error

A DEX Failed error means the Nayax terminal cannot transmit data.

Steps to Fix:

  1. Restart the Vending Machine:
    • Open the vending machine.
    • Turn off the power for 30 seconds.
    • Turn it back on and retry DEX transmission.
  2. Restart the Nayax Terminal:
    • Access Technician Mode on the Nayax device and restart.
    • OR, use the MoMa App to restart remotely.
  3. Check DEX Cable & Connections:
    • Verify that the DEX cable is securely connected.
    • If damaged, replace it.
  4. Manually Reload Data in the MoMa App:
    • Open the MoMa App.
    • Navigate to More → Last Data Update.
    • Select Reload Data.
  5. Replace the Nayax Terminal (Final Step):
    • Turn off the vending machine.
    • Remove and replace the Nayax device.

Best Practices

Power & Hardware Issues

Power Down Error If the machine has lost power, it may be due to:

  • Power outage
  • Loose power connection
  • Defective power supply

Solution:

  • Ensure the vending machine is plugged in.
  • Check the Nayax terminal power connection.
  • If necessary, replace the power supply unit.

Antenna Disconnected from Circuit Board

  • Open the vending machine.
  • Disconnect power before handling electronics.
  • Ensure the antenna is securely connected to the circuit board.
  • Reconnect the antenna if loose.

How to Restart the Nayax Terminal

Using the Terminal Itself:

  • Press the menu button (three lines).
  • Navigate to Technician Mode.
  • Enter your password.
  • Select Restart.

Using the MoMa App:

  • Select the machine in the app.
  • Go to Tasks and Warnings → Actions → Restart Device.

How to Clean the SIM Card

  1. Turn off the vending machine.
  2. Open the Nayax terminal and locate the SIM card.
  3. Remove the SIM card and wipe the contacts with a dry cloth.
  4. Reinsert the SIM card and close the terminal.
  5. Restart the vending machine.
  • Proactive Maintenance: Regularly inspect connections and monitor device status via the Nayax portal.
  • Stay Updated: Keep firmware up-to-date to ensure seamless operation.
  • Training Resources: Refer to Nayax's online manuals and VTM Vending's training videos for setup and maintenance.
All Posts

9 comments

I really like the intersection and it is very easy to understand thank you

Joel K Smith

RSSI 99: Easy guide to follow…

In the world of Nayax, RSSI 99 means “No Communication.” Use this simplified guide to get your machine back online.

Step 1: Check the Antenna Connection
Ensure the antenna cable is firmly popped/clicked into the port on the back of the Nayax unit.

This is usually a snap-on connector (not a threaded screw).

It should feel seated firmly and not wiggly.

Step 2: Position the Antenna Pole
The cable leads to a magnetic base.

Make sure the antenna pole (the stick part) is screwed tightly onto that base.

Place the base on the top of the vending machine (outside).

Important: Ensure the cable is not being pinched when you close the vending machine door. You may need to shift the magnetic base to align the cable with a hole or gap.

Step 3: Clean and Reseat the SIM Card
If the antenna is fine, the device may not be “talking” to the SIM card.

Power Down: Turn off the vending machine power entirely.

Locate & Remove: Find the SIM slot on the side of the unit. Slide the metal bracket to the Open position and remove the SIM.

The Cleaning Trick: Use a soft cloth or a pencil eraser to gently clean the gold contacts. Oils or dust can cause connection drops.

Reseat: Place the SIM back in (ensure the notched corner is oriented correctly). Slide the metal bracket back to the LOCK position.

Step 4: The “Hard” Power Cycle
A simple menu reboot often isn’t enough to reset a hung cellular modem.

Unplug the Reader: Disconnect the MDB cable (the main white or black multi-pin plug) from the back of the Nayax unit.

The Wait: Keep the unit unplugged for at least 3 full minutes. This allows the internal power to drain completely.

Reconnect: Plug the MDB cable back in and power the machine on.

Patience: Wait 5–10 minutes. The device will show “Init Modem” or “Please Wait.” It takes time to scan for towers and clear the 99 code.

Signal Strength Guide
Once the 99 is gone, check your numbers:

1–12: Critical (Very poor connection)

13–19: Fair (Stable)

20–31: Excellent (Optimal)

Jordan

I have a Nayax with high gain antenna at the location with poor reception. My RSSI stayed around 13 and I need something to raise it above 15. Is there any way you can recommend to fix the reception issue?

Stephen Mooney

So Kiosoft is better than Nayax?

Jason

https://vapetm.com/blogs/master-nayax-guide/nayax-card-readers-complete-settings
Master Nayax Settings and Explore Kiosoft

Jordan

Leave a comment