I have downloaded and used Arduino IDE v1.8.4 from official site (needs no install) for windows10, and connected my random board with a ch340, but it's LED is only blinking and I can't select the port (ie. it's grayed).

I did test all USB ports and restarted my laptop but that didn't work!

I tried to install 1.6.9 IDE that I had before, but again the port option is unselectable!

This is my board: http://uupload.ir/files/xgv_uno.jpg

  • 1
    What OS are you on? Is it a Genuine Arduino board?
    – Majenko
    Commented Sep 21, 2017 at 11:23
  • Which LED is blinking? Any chance of a screenshot?
    – sa_leinad
    Commented Sep 21, 2017 at 12:19
  • Have you tried a new cable? or a different laptop? If you have is its possible you have the wrong board selected? Commented Sep 21, 2017 at 15:59
  • 1
    @sa_leinad: i have edited my question
    – WDR
    Commented Sep 21, 2017 at 18:31
  • 1
    @CodeGorilla: Cable is OK, and I have no computer at know to test it
    – WDR
    Commented Sep 21, 2017 at 18:32

1 Answer 1


Simplest possible thing would be that you do not have CH340g driver installed and you should try installing it first; These boards use CH340 for usb to serial and they need the driver to be installed; Please give it a try by getting the driver from the following link http://www.wch.cn/download/CH341SER_EXE.html or any other reliable source if there is any problem with the link;

If the board is not recognized even after that, it could be a bad USB port or a bad USB cable or even a board with the CH340 chip dead;


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