SD card + Arduino leonardo + external power 6AA

Hello!

I have an arduino leonardo and a SD card module. I make the connection via ICSP (MISO, MOSI, CLK) and works perfectly using USB power.
But if I use external power (jack with 6 AA) did not create any file in the SD.
What happening? The SD card only works with USB power?

Thanks!

6 AA should be good.
Can you measure the voltages ? like the Vin, 5V, 3.3V ?