Chosen Solution
iPhone 6s vibrates slightly but not turning on have tried battery and screen on another iPhone both work fine could it be logic board or something else? It worked fine with smashed screen gone to change over screen but won’t turn back on can’t understand why when on main part of phone nothing was touched
Either damaged screen connector on board or blown backlight filter. Filter is extremely easy to blow up if the screen was connected / disconnected from the board while the battery is plugged in on the iPhone 6s. Either of those will require a reputable repair shop that does micro soldering / board repairs to fix those problems. You may be able to find someone locally in your area that offers that kind of service.
