[beagleboard] New here, Need help~My BBB wireless can not connect the win10 or ubuntu via PuTTY

I am new to BBBW, last week I first open and turned it on, install the drive and connect it via putty, tested it wifi function and ping Google successfully, after that I notice that the system version is early in 2017, so I followed the web instructions download and used a TF card to flash it, and then I flashed successfully

After that, on the win10, I can use Putty to login and test it with a external USB to RJ45 port and the plug a network cable in it, this board automatic and connect the internet.

After that I turn it off, maybe directly unplug the micro usb, after that I can not connect the board by putty anymore. Every time I turn it on, after 1 minute the power/WL/BL light normally on while and usr0/3 blink, usr2 normally on, and then I can find it in the win10 like USB, after 1 minute the usb logo disappear and then reconnect(cause I can hear the voice from the win10), but can not see the usb logo and can not see the inside…Putty can not connect this board again

After that I reflash many times with different images, change TF card ,change PC but still the same, after 1minute the PC can identify the board, after that the flash disk logo disappear from my computer, and never appear again, and putty can not connect the board through the whole period.
And sometimes the USR0 normally on sometimes the USR2 normally on but the power/WL/BL light is always on, sometimes it is stuck I press power button but change nothing, have to unplug the micro usb to turn it off…

so, the thing is I only used the micro usb cable to supply its power, I bought a 5V/2A power and a UART8000-U to TTL 3PIN cable, but they are on their way, I can test the board via TTL next week maybe. So it may due to the power current is not enough?But at first I can login it, or the board is something wrong but I can not fix it by reflash? Should I change a board from the supplier, but they are in Hongkong, far away from my home…