Replace Chip

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?
Thanks
David

Try this:

Hold down the Reset button.
Unplug the USB cable.
Plug the USB cable back in.
Click on the Upload button.
When the LEDs on the board flicker, release the Reset button.

dvdmoylan:
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?
Thanks
David

Hi
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 :stuck_out_tongue_closed_eyes:). 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

Thanks for giving up your time for the advise, i had tried all the options ye suggested. I finally got it going.

Held Reset
Uninstalled arduino in device manager
Plugged out arduino
Plugged in arduino
Waited for driver to install
Uploaded the blink sketch
Released Reset when upload was complete