Why the board won't work normally if I pull out the USB?

[Hihdl 0]

I have bread boarded two Nano modules both have their own NRF24L0 radio. Both boards work perfectly when attached to a computer USB/power port.

Both talk back and forth sending and receiving data. Works great.

However if I pull out the USB/power cable from one board and supply 9 volts to Vin .... it won't transmit or receive anymore. I plug the USB/power/communications cable back in and everything is back to normal. I've even used a 120Vac to 5Vdc adapter with a USB output connector and same thing. Won't Transmit/or receive.

Any ideas?

[D@n 408]

@Hihdl,

Questions about the nano devices really belong on the Terasic forum.  You're more likely to get a Nano engineer on that forum than on this one.

That said, were I you, I'd pull up the schematics and look at the power supplies.  Are they designed in order to able to handle a 9V battery, or do they need a 5V source?  Check your 9V with a voltmeter, does it have the charge you think it does?  etc., etc.

Dan