Check your mobile device is compatible, ensure your card reader and mobile device are charged and check your app is updated.
Reset your card reader's Bluetooth
If your device is compatible and card reader is charged, but you still can't connect, try resetting your connection.
On your Solo, tap the arrow at the top of the screen and select "Connections".
Disable the Bluetooth toggle.
Wait a few seconds and then enable the toggle again.
Once you've reset your Bluetooth, try manually reconnecting your device.
Additional troubleshooting
If your Bluetooth connection still won't work, try restarting both your card reader and the device you're trying to connect to.
If connecting to a phone or tablet, you can also try clearing your Bluetooth app's cache in your phone or tablet's settings.
Your device may be defective or blocked. Find out what to do with defective card readers.