Your Cel-Fi Duo+ may be experiencing a hardware error.
Hardware errors may be remedied by a reset. Your DUO+ may not display a flashing error code. You will likely only see the solid red power indicator on your Unit.
Try this…reset your Unit. Simply unplug your Unit for a few seconds and plug it back in.
If after restarting your Cel-Fi DUO+ your hardware issue remains you will need a warranty replacement from your point of sale. If you received your Cel-Fi DUO+ from your cellular provider, reach out to them for support. If you purchased your Cel-Fi DUO+ from Cel-Fi.com please contact us.