When I plug the USB cable to my Arduino and try to upload a sketch I get thtis error:
avrdude: ser_open(): can't open device "/dev/cu.usbmodem1411": No such file or directory
ioctl("TIOCMGET"): Inappropriate ioctl for device
when I go to Tools > ports I can't find the USB port. The Arduino still working and green light is on, so what is the problem exactly?
I have tried with 2 Mac laptops, same thing happened. an electronics guy told me that the IC is burnt, is this right?
when I go to Tools > ports I can't find the USB port.
So the bit of the Arduino that talks to the USB is broken.
an electronics guy told me that the IC is burnt, is this right?
Could be.
Did it work before?
What were you doing and what was connected when it died?
There's a basic rule of troubleshooting that you never really know for sure what the problem is 'till it's fixed.
So... If you get another Arduino and it works, you'll know the old one is fried...
Try stopping the IDE unplugging the Arduino and then re-plug the Arduino, then restart the IDE.
Look at the Hardware monitor under System and see if the Arduino shows up.
If the above doesn't work, get another Arduino, try a different USB port, or look up 'In circuit Serial Programming'.