Im using an arduino Mega 2560. For some reason its not showing up in the COM and LPT ports when I connected it to my pc. For a while it was being shown as an unknown USB device, so I tried to install the driver again. But it didint help and after a while it doesnt show up even in the unknown USB device when I connect it.
I must mention here that the atmega 16 on the board heats up when I connect it to the pc. I dont think it happened before, but this might be the cause of the problem.
if that chip heats up prety fast most of the time its tousted and you'l have to replace it (or in this case its more likely cheaper to get a external programmer or an arduino uno and use that one for programming your mega
i'm not a specialist in these things and i know that it processors do heat up when they are heavely used,
but i never heard of a heating microcontroller that is working properly (or withing the specs)