If a machine connected to a PI unit (photo below) is not receiving credits, follow the troubleshooting steps below to verify the ribbon cable connections and identify the correct pulse channel.
1. Confirm Whether the Reader Has Ever Worked
First, determine whether the reader has worked correctly since installation.
If it worked previously: the issue may be related to a loose cable, coin mech, machine interface, or another connection issue.
If it has never worked: the reader may be configured to the wrong pulse channel.
2. Check the Ribbon Cable Connections
Hold the PI unit with the USB ports facing up (see photo above).
Verify that the ribbon cables are connected as follows:
Left ribbon cable port → Coin Mech
Right ribbon cable port → Machine
Make sure both ribbon cables are fully inserted and securely connected.
Important: If the coin mech and machine are connected to the wrong ports, the reader will not work correctly.
3. Test the Coin Mech
Insert a $1 coin into the coin mech.
Check whether the machine receives the $1 credit normally.
If the machine receives the credit, continue with the channel test below.
If the machine does not receive the credit, check the coin mech and ribbon cable connections first.
4. Identify the Correct Pulse Channel
The PI unit has six Channel LED indicators (1–6) located directly below the ribbon cable connectors, as shown in the image.
When a coin is accepted by the coin mech, one of these LEDs should blink briefly.
To test:
Insert a $1 coin into the coin mech.
Watch the Channel LEDs 1–6.
Identify which LED blinks when the coin is accepted.
Record the channel number and provide it to support.
The reader is normally configured to Channel 6 by default. If another LED is blinking, the reader may need to be configured to use that channel instead.
Tip
The Channel LED blinks very quickly and can be difficult to see.
Use your phone to record a video while inserting the $1 coin, then replay the video slowly to identify which Channel LED blinked.
What Information Should I Send to Support?
Please provide:
Whether the reader has ever worked correctly
Confirmation that:
Coin mech is connected to the left port
Machine is connected to the right port
Whether the machine receives credit when a $1 coin is inserted
The Channel LED number (1–6) that blinks when the coin is inserted
With this information, support can confirm whether the reader is configured to the correct pulse channel and advise on the next step.