What is a common sign that a power adapter is defective?

A common sign that a power adapter is defective is when the device fails to charge or power on while plugged in. This indicates that the power adapter is not supplying the necessary voltage or current to the device, preventing it from operating properly. If a device shows no signs of life even when connected to a power source, it points directly to a problem with the power adapter, as this component is responsible for converting AC power from the outlet to a usable form for the device.

Other symptoms can also provide clues about potential issues, but the inability of the device to charge or power on while connected is the most definitive sign of adapter failure. For example, a device that runs out of battery quickly might indicate other issues such as battery health problems, and signs of high temperatures could result from various hardware malfunctions, including overheating internal components. Unusual noises often suggest mechanical or electronic disturbances unrelated to power supply issues. Therefore, the failure to charge or power on, while connected to an adapter, stands out as a strong indicator of a defective power adapter.