I am not sure which process for resetting you tried, but I’ve seen a lot of places and people say to hold the power button for 10 seconds. However… I found a video from someone who said that if you push the power button and the mute button simultaneously for exactly 2 minutes or more while charging. If it doesn’t work, try it again off the charger.
My OG Studio wireless headset was broken for 3 years (simple headband fix) so I didn’t turn them on or charge them. After fixing them a few moments ago, I was alarmed when they didn’t light up when charging. But I took very good care of them and knew that everything should still work properly.
I’m glad I tried this. It really worked! Hopefully it will help someone who needs it.