Certified Biomedical Equipment Technician (CBET) Practice Exam 2025 - Free Biomedical Equipment Technician Practice Questions and Study Guide

In this scenario, the most likely issue is a blown fuse. A wall-mounted otoscope typically includes an internal fuse to protect its electrical components from damage due to excess current. If the device is not functioning even after changing the lamp and confirming that it is plugged in, it indicates that electricity is not properly reaching the otoscope's operational components.

A blown fuse would prevent power from traveling through the circuit, leading to a complete failure of the device to operate. This is a common failure mode in many electrical devices and is a logical next step after ruling out the lamp and plug connection, as a functioning lamp confirms that the device was receiving some power initially.

While other options might seem plausible, such as a power surge potentially causing issues, it's often the blown fuse that directly interrupts power flow in devices with protective components. A defective receiver may be a possibility but is less common compared to a blown fuse in this context. Similarly, a dead battery is irrelevant for a wall-mounted device that operates on mains power unless specified otherwise.