I have a sainsamart arduino mega2560. I used it for a couple of days but now it is not working. The onboard LED(13) is always on. Even if I press the reset button, nothing happens.
When uploading a code the following error comes. And the 13 LED remains on. I am a complete noob in arduino so please help.
Arduino: 1.6.6 (Windows 8.1), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)" Sketch uses 1,518 bytes (0%) of program storage space. Maximum is 253,952 bytes. Global variables use 9 bytes (0%) of dynamic memory, leaving 8,183 bytes for local variables. Maximum is 8,192 bytes. avrdude: ser_open(): can't open device "\\.\COM11": Access is denied. avrdude: ser_drain(): read error: The handle is invalid. Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions. This report would have more information with "Show verbose output during compilation" enabled in File > Preferences.