I'm gonna cry.
Just installed my new Holmes Hobbies SHV500 servo and Hitec Proton rx in my Rival. Connected the servo's power lead to the balance port of my 3s lipo and instantly cooked everything. Servo wiring melted, rx fried, ESC dead.
Verified polarity with a multimeter before I connected the servo power, and have no idea what happened.
So frigging upset right now.