All of a sudden can't get S6 to turn on.

[AC Question]

Is there a way to turn on other than just with the power button?

 

[Tim1954]

No. Just hold the button down until it happens. Make sure the battery is charged.. It might take half a minute, so just hold it and be patient.
If zero happens, it's time for repair shop.

 

[pontiac005]

Try holding the power and home button down at the same time.