Vm202n dont work with usb supply

Hi ! My vm202n works perfectly with a battery supply but not with a usb power supply (phone charger 5v dc, 1 A). How can I solve this problem ?

What are the symptoms when you connect it to the power supply?
Have you checked the output of the power supply?
How are you connecting it to the VM202N?

The output is ok, I checked it with a voltmeter. (5,2 volts). I plugged the red wire of the charger on the + pin and the black one on the ground pin of the module. The usb key with mp3 file is blinking (not exactly the same way it does when I successfully plug the module on batteries) but there is no sound (i plugged a mm210 amp with a different power supply on the mp3 module). The system works fine with 6AA batteries - with a higher voltage, so. Same problem when I plug an external usb phone battery.

When you are attaching the 5volts you’re not using the resistor are you?
I don’t think it needs one for just 5volts

No I dont use the resistor. Any idea ?

Are you feeding the straight into the unit with the connector (green arrow) not the red arrow.