How am I supposed to know if SMC reset has taken place? I have a Macbook Air (mid - 2013) which means non - removable battery and currently it's running El Capitan OS X. I tried to do some SMC reset by pressing 


shift + control + option + Power button


but there light indicator on the MagSafe adapter does not change any color. It used to do so when I first got it. But not anymore. So, how am I supposed to know if SMC reset has taken place?
A SMC or PRAM reset will invoke the Boot Chime to activate or become louder.
I would also suggest verbose mode (Cmd+V) and look for a reset message.