I'm using an elegoo uno r3. Recently connected it and an hm20 Bluetooth module to a breadboard and It worked perfectly fine, sketches could be uploaded, it was being recognized by the ide and was connected by the cable.
I tried to connect a 9v battery to the breadboard as normal and then removed it to reconnect it with the ide with the cable to fix something. When I used the cable after this, the board isn't being recognized but is turning on (the green light and L led are on) nothings running and I removed it from the circuit entirely. I tried a different board (arduino uno) with the same cable and it was recognized. It's just this board giving me some trouble. It's not being recognized under ports either. I tried another laptop and still nothing.
By “normal” do you mean it was connected to the VIN pin or the 5v rail? 9volts connect to the VIN pin is fine but 9volts connected to the 5v rail is bad.
I think we need to see some schematics as the word salad is a bit confusing.
You have clearly damaged your board with what you have done. What we need to establish is exactly why so that you don't do it again. But it does look like your board is toast.
I added a 9v battery an ultrasonic sensor, and bluetooth module like this; (img will be attached in a bit) it connects to my laptop via the cable fine but it's not detected by the port under device manager or the ide. The only two led's on were the greenlight and the L led. I tried with the same laptop and ide and the uno is working fine but the elegoo seems like a lost cause :c