Applies to: Bus-powered USB audio interfaces
The USB icon on our interfaces either flashes red or doesn't illuminate at all if the device is not receiving enough power to connect.
Here are some steps to try if you encounter this.
Try a different USB cable
USB cables longer than two metres can sometimes cause issues. Ensure the replacement USB cable is shorter than this. For more information about USB cables, please see here.
Power your interface from an external power supply/adapter
Scarlett 2i2 and 4i4 4th Gen
As well as the main USB port, the Scarlett 2i2 has an extra port on the rear panel, labelled 5V DC, which you can connect an external power supply to if none of the USB ports on your computer supply enough power.
You can use any 5V USB power supply, such as those supplied with mobile phones and tablets. You need a second USB cable to connect from the power supply to the 5V DC port on the 2i2. The 5V DC port on the 2i2 is a USB-C type port. The second USB cable needs to have USB-C on one end and either USB-A or USB-C on the other end, depending on the type of port on your power supply.
Steps to connect:
- Disconnect the original USB cable from the port labelled 'USB' on the 2i2
- Connect the second USB cable to the power supply
- Connect the other end of the second USB cable to the 5V DC port on the 2i2
- Connect your power supply to a mains power socket and turn it on
- Reconnect the original USB cable from your computer to the port labelled 'USB'
All other bus-powered interfaces
Use a mains-powered USB hub or a USB-C hub with Power Delivery to ensure your interface is receiving bus-power. See Connecting a bus-powered audio interface to an iPhone or iPad for more information on these peripherals.
In most cases, USB power banks do not provide enough stable power for our interfaces to function. We only recommend using mains-power if your iPhone/iPad cannot provide enough bus-power.
Loose USB connection
A slightly loose USB connection can prevent Scarlett 4th Gen being recognised by your computer, or receiving sufficient power. Try pushing the USB cable firmly into the USB-C port on the rear of the interface, so it 'clicks' into place; this may resolve any power or connection issues you are experiencing.
If you are using both the USB and 5V DC ports on a Scarlett 4th Gen with two USB ports, press both cables in firmly.
If you've completed all the steps above with the recommended equipment, but you are experiencing sound issues, please see our Sound issues on iOS and iPadOS article.