I have a original Arduino Mega 2560 but the com port is not available. the field is bright grey and i cant choose any com port.
in a lot of forums the solution is to install the ch341ser driver but in my case it didnt work. Do you have any other solution or opportunity to try out?
Is that all on the big chip? There is a smaller one next to the USB port; might be difficult to read. If it's square with legs at all sides, it is a 8U2 or 16U2; if it rectangular with legs at two sides, it a CH340 or CP21xx or FTDI232.
Also not somewhere with a yellow triangle?
Bad cable or not properly inserted cable?
Did you use it before and it used to work? Or did it never work?
I can't advice much further. Not showing up in device manager when using the same (properly inserted) cable that works for the Uno would, in my opinion, indicate that the 16U2 is broken in some way.