iPhone 6 wont turn on

Dead. This thing is as good as paperweight now unless you bring it to Apple.

Unplug the battery and hold the power button for 15 seconds then plug the battery back in and try to turn it on. But you replacing the home button wasn't a good idea because now the Touch ID functions will never work again

If you unplug the new home button and use a known good home button you can get the phone to power back on by unplugging the battery for a few seconds, plugging back up and use the home and power button together to get the screen on.

The issue is within the new home button itself. It shorts the phone and the phone goes off and won't come back on. Usually doesn't cause any actual issues, it is just how the phone reacts to the home button. It is probably too late for that button, you will need to get another one. Make sure the phone and screen are on when you plug in the new home button, at that point the button will work.