Payment not registering

A customer inserts coins or bills into the payment device, but the booth's credit balance doesn't update. This article walks through the common causes.

Symptom: PCB pill is red, or customer claims they paid but credits never appeared.

Quick check first

  1. Open admin → Diagnostics tab.
  2. Look at the PCB status card.
  3. Read the status pill and message.
  • Listening on COM3 (or similar). The PCB is connected and BoothIQ is listening. Check the actual coin acceptor
  • Port not available. The COM port BoothIQ expects isn't there
  • Connection error. The serial connection failed
  • No data received. BoothIQ is listening but the device hasn't sent anything
  • Device not detected. The USB-to-serial adapter or the PCB itself is offline

Step 1: Have the customer try again

Most "the coin didn't register" reports are actually the coin was rejected by the acceptor (wrong denomination, dirty coin, jam) and the customer thinks they inserted it.

Watch the customer insert the coin:

  1. Did the coin actually go into the acceptor, or get pushed back out?
  2. Did you hear a "click" or "ding" sound from the acceptor when it accepted?
  3. Did the credit balance on screen go up?

If the coin came back out, it was rejected. Have the customer try again with a different coin.

Step 2: Check the PCB pill in admin

If the PCB pill in the dashboard header is red, the booth isn't talking to the payment device. Open the Diagnostics tab and read the PCB section's specific error message.

Step 3: Check the COM port

In the Diagnostics PCB section:

  1. Find the COM port selector dropdown.
  2. The dropdown lists every COM port the booth can see.
  3. The currently selected port should be the one the PCB is wired to.
  4. If you're not sure which port is correct, try each one in turn and watch the PCB card status update. The right port shows "Listening on COMx" with no error.
Note
The COM port can change if Windows reassigns it after a USB unplug/replug. Once you find the right port, leave it set.

Step 4: Listen for live pulses

In the Diagnostics PCB section, there's usually a live pulse activity view that shows pulses as they arrive. To test:

  1. Confirm the PCB is "Listening" on the right port.
  2. Insert a test coin or bill into the acceptor.
  3. Watch the pulse activity view for a count change.
  • Pulses arrive when you insert a coin → the booth and the device are talking. The credit balance should also update. If it doesn't, see Step 5.
  • No pulses arrive → the booth isn't receiving from the device. The COM port may be wrong, or the cable is bad.

Step 5: Pulses arrive but credits don't

If the live pulse activity is incrementing but the credit balance in the Credits tab isn't changing, BoothIQ is receiving pulses but failing to record them. This is unusual.

  1. Power-cycle the kiosk to clear any stuck state.
  2. Repeat the test.
  3. If pulses still don't become credits, contact support. This is an internal issue.

Step 6: Power-cycle the payment device

The payment device may have its own internal state that gets stuck:

  1. Find the payment device's power source (it may share power with the kiosk, or have a separate cable).
  2. Power-cycle it. (If it shares power with the kiosk, just power-cycle the kiosk.)
  3. Wait 30 seconds.
  4. Check the PCB status pill. It should turn green.
  5. Test with a coin.

Step 7: Bill acceptor jams

If the booth has a bill acceptor and bills are being rejected or jammed:

  1. Look at the bill slot. Is there a stuck bill visible?
  2. If yes, the bill acceptor likely has a service door. Open it carefully and remove the jam.
  3. Close the door, wait for the acceptor to reset (usually a few seconds).
  4. Test with a known-good bill.

If the bill acceptor jams repeatedly, it may be dirty inside. See Coin and bill acceptor care.

Step 8: Coin acceptor jams

Same as bill acceptor. Open the service compartment, remove the jam, close, test.

If coins are being randomly rejected, the acceptor may need to be calibrated or reprogrammed to accept your local currency. This is hardware-specific; contact support.

Step 9: When to call support

Contact support if:

  • PCB pill stays red after multiple power cycles and COM port changes
  • Pulses are received but credits aren't recorded
  • The payment device physically jams repeatedly
  • Customers consistently report payment issues you can't reproduce
  • You suspect the device is undercount (always credits less than the customer inserted)

Workaround: switch to Free Play

While you're troubleshooting, you can temporarily put the booth in Free Play mode so it can still serve customers (without charging):

  1. Open admin → Settings → switch to Free Play.
  2. Confirm the Mode pill in the header.
  3. Customers can still take photos and print, but they won't pay.

This is much better than taking the booth completely offline. See Operation modes.

Common causes

Customer inserted a non-accepted coin.

Tell customer to try a different coin.

Coin / bill jam.

Clear the jam.

COM port reassigned by Windows.

Pick the right port in Diagnostics.

USB-to-serial adapter unplugged.

Internal cable. Contact support.

Payment device stuck after a power blip.

Power-cycle the device.

Payment device dirty inside.

Clean it (see Maintenance).

Payment device physically damaged.

Replacement needed. Contact support.

Verify it worked

Payment is recovered when:

  • The PCB pill is green
  • Pulses arrive in the Diagnostics view when you insert a test coin
  • The credit balance updates correctly
  • A full customer session in Coin Operated mode completes from payment to print

Next steps