Hi, I have an arduino UNO, when I try to upload a sketch it fails as it does not see the com port, device manager see UNO when it is plugged in. The previous sketch is still operational but no matter what I try I cannot upload a new sketch, could the previous sketch get stuck in a loop and hog the com port. Would installing a new chip with boot loader installed resolve the issue?
Did you ever move your ATmega chip from the socket and put it on again? if you do, check the orientation . ATmega label is upsidedown relative to Arduino board (took me one morning of my life
). Open a arduino photo from web it will help you
Check TX and RX leds if RX blinks 3 times, that means USB drivers are OK install, if TX doesnt blink that means ATmega doesnt response