A:Answer The flashing yellow lights indicate you are not using the correct charger that came with the duo. in order to use this charger you MUST use the Samsung 25W charger that came with it. The same is true for any other higher wattage chargers if you want to use fast charging. I am not happy about this as I have many chargers over 10-15 Watt that work with pother phone brands, but Samsung restricts it.
If working properly, you phone would light up indicating a charge and the light on the Duo would be red depending on which side you placed your phone.
