Transistor Lower Base Bias Resistor Open Circuit Tutorial

There is no potential divider action and the full +9 volts is applied to the base by R1.

This causes a high base current to flow, which in turn causes a high collector current to flow.

There is a large volts drop across R3, causing a low collector volts.

There is a large volts drop across R4, causing the emitter volts to rise.