General questions about the device to identify some problems

My watch worked before, replaced screen (screen was working), but after repair device its not working anymore . Screen and/or watch doesn’t turn on. I think it is a motherboard problem, but it could be the screen. I cant seem to turn the device on, althought there was 1 single time that i was messing around and i managed activate the countdown emergency sound, meaning it was on. Also, it seems that sometimes it vibrates when pressing both digital-crown and power button.

1 - Does the apple watch s4 turn on without a screen (can you ear the countdown sound or feel vibrations)?

2 - Does it turn on with a damaged force touch basket?

3 - Does it vibrate on force-reset combination?

Edit: seems that it vibrates almost always on pressing force-reset keys combination. What does it mean?