Hi, I have beating my head against the wall all weekend over this.
The board is a DccEle - DCcduino Mega 2560
My environment is MAC OSX 10.9.4
When I connect the board, blink (I assume preloaded) does the flashy thing at 1 second intervals - so the basic board functionality works.
In the IDE there is no serial port.
Looking at System information, I can see the following;
Product ID: 0x7523 Vendor ID: 0x1a86 Version: 2.54 Speed: Up to 12 Mb/sec Location ID: 0xfd130000 / 5 Current Available (mA): 500 Current Required (mA): Unknown (Device has not been configured)
My research says it is a HL-340 which is based on the prolific pl2303 chipset.
I have put in pl2303 drivers (in /system/Library/Extensions - after configuring the .plist to add the vender/device (6790,29987) but still and enormous amount of nothing.
The system log shows
Does a 'real' mega 2560 use the same chipset for the serial port.
Is it possible that the pcscd daemon sees the card but can't configure it (as a smart card) and it does not allow the pl2303 extension to have a go?
I can return the card but after a couple of days on and off trying to get this to work I am starting to get belligerent :-)
Note: Something good did happen with all my screwing around. My Due still works ok and the uno now actually says 'Arduino Uno' in the IDE for the port - which is good when I am developing for both at once.
I will break out a windows 7 laptop and see if I have better success - if nothing else I can have a look at the MEGA windows.inf and see if any clues are in there.