Arduino not working

Hey People

My arduino was working perfectly. I made a 3x3 led matrix and powered it directly from my mobile usb charger. It didn't work properly there(2 or three leds blinked). Then i put it again into my computer, it doesn't show up there as a available com port. I tried updating driver but that too did not happen. But the power on led on arduino glows.

please help me out.

what is the voltage of that USB charger? How did you connect?

What Arduino? UNO/MEGA/DUe?