Why doesn't my screen turn on if the battery isn't plugged in?

My phone's screen does not turn on unless my battery is plugged in. If the battery is not plugged in, but it is plugged into the wall, it shows a screen telling me to plug in the battery. When the battery is inserted, the screen is able to turn on and behave normally, except I can't see what's happening. The screen has taken no damage, and it is newly replaced with this guide. No other part of the phone has taken physical damage.