Did I just kill my arduino uno?

Hey.... So I think I managed to kill (one of) my many arduino uno's. (R3). I realised this when I was experimenting with a 5V sensor and a another piece of hardware that operated on 3.3V and halfway through uploading the code I realised in my breadboard that I had a row with 5V and 3.3V connected. Of course I unplugged the usb cable and made necessary changes to my breadboard, double checked my breadboard, all that stuff, but I started to notice some strange behavior from that specific board I think I fried. First of all, I was doing stuff with the nrf24l01+ between two arduinos and one arduino kept timing out on the server (the server is the arduino I fried), and I noticed that the server arduino wouldn't print anything other than garbage into the serial monitor when I switched rolls, and I was constantly getting the error, 'Board at COM24 not available'. So I did a test where every 5 seconds it prints in 'bob' to the serial monitor. This is what I got:

bïb âoâ âob âob bob

So what I am asking is did I kill the atmega 328p or the serial (the surface mount) chip? Because when I upload a sketch such as blink, it works fine. Thanks!

Serial communication should work if the upload works fine. It is the same line. Check your terminal settings first.