What is the consequence of a blown input fuse, F1, on the power supply?

When an input fuse, such as F1, blows in the power supply system of a FANUC controller, the immediate effect is that the power distribution to the controller is interrupted. This lack of power prevents the system from functioning properly. As a direct result, the teach pendant, which relies on the controller to display information and enable interaction with the robot, will not power on or display any information. This absence of a display indicates that the controller is not receiving the necessary power due to the blown fuse, rendering the teach pendant non-functional.

While other outcomes, such as a restart or triggered warning signals, might be possible in other scenarios involving different kinds of faults, a blown fuse specifically cuts off power completely, leading to the no display condition on the teach pendant. Safe mode is typically a state that the system can enter to prevent damage when operational conditions are outside acceptable limits, but in the case of a blown fuse, the power loss would prevent any operational state from being established at all, further reinforcing the reasoning behind the correct answer.