Here’s the secret Ninja gremlins don’t want you to know: the blender checks if the lid is locked. If it’s even a tiny bit crooked, the motor will refuse to start. It’s like a toddler who demands the sippy cup be perfectly aligned.
Twist that lid until you hear a second click. Some models have a clear plastic cap in the center—make sure that’s pushed down too. I once spent five minutes trying to blend a smoothie before realizing the cap was slightly askew. The blender was judging me.
How Do You Turn On The Ninja Blender at Kirsten Nord blog