Crash When turning on Observer

Alcatel One Touch Flash Plus

I was trying to turn on the back side of observer with piston. And when the piston connected with observwr its crash

What I expected to happen was...:
When I turn it on, the tnt is exsplode

What actually happened was...:
Instead, it doesnt do annything

Reproduce:
1. Take Observer.
2. Turn it on by piston (connect it)
3. And bam! Its crash to home screen