usbpush can't recoginze mini2440 on ubuntu 64b 15.04

Richard Huynh
Hello Community,

Few day ago Ubuntu could recognize mini2440 and transfer file smoothly.
However recently, it couldn't recoginze.
I checked by lsusb or dmesg and also don't see mini2440 bus presence ...
Anybody faced this issues, could you please support me?