Dear Alex,
Thanks for getting in touch with us.
I’m sorry you’re having a problem with your LEGO® MINDSTORMS® EV3! I can imagine it's frustrating to not be able to to connect the Brick to your computer via the USB cable. You've already tried several of the things we would usually suggest you do in this sort of situation, so it sounds like something is very wrong here. There are a few more things we can try.
You say you've tried resetting the Brick. Did you do this while following the steps outlined in this article? If a reset isn't done properly, that could end up causing more problems. I would also suggest deleting the MINDSTORMS software from your computer and re-installing it. Make sure you're downloading an official version from LEGO directly, you can find the Home software here and Education here.
Something else you can try is to turn on the Brick, plug it into the computer, and then turn the computer off completely. Leave it off for about 30 seconds and then restart. This can sometimes help trigger a connection.
If none of this helps, then we'll need to investigate the matter further to see what exactly the problem is. To do that, I'll just need to ask you a few questions:
- Does the Brick behave normally when connected via Bluetooth, or just on its own?
- Do you get any response at all on the Brick itself or the computer when you try to connect via USB?
- What version of the MINDSTORMS software are you using (Home or Education)?
- What model of PC and MAC have you tried, and which operating systems were they running?
This was from LEGO.com/service