My Arduino UNO R3 isn't working at all after attempting to flash HoodLoader2. The one I have is a clone, but despite this it has a 16u2 (if it isn't a fake one). I did this several months ago and remember not succeeding, but I can't remember if I corrupted something on the UNO. From some research, I think something to do with the 16u2's firmware is corrupted but I'm not quite sure.
After plugging it in my PC via USB, the orange LED that would usually blink before starting to do execute code (LED labeled L) would just stay lit. The UNO doesn't react to me pressing the RESET button, nor does it show up in Arduino IDE or Device Manager.
I'm pretty sure I'll have to buy a second one so I can fix this one, but if any alternative is available, I'd prefer not to have to buy another UNO.
So apparently it may be fried from connecting a 9V supply or a 12V one (several months ago). Just checked 5V and 3V with multimeter, 5V is fine but 3V seems dead. It didn't give off any smoke but I may have fried the 16u2 doing that. Hope that isn't the reason it is working.
Loopback test failed (the COM port won't show up at all in IDE nor in Windows).
If any more information is needed to fix the issue, I'll gladly provide it.
Turns out, if my Arduino wasn't dead, now it definitely is. Tried plugging it into a 9V power supply... The 16u2 started smoking. I'll probably get a new one off AliExpress and use it as a ISP for the 328p if it turns out alive.