How do you check a ac adapter?

To check an AC adapter, first inspect it visually for any signs of damage, such as frayed wires or burnt components. Then, use a multimeter to measure the output voltage: set the multimeter to the appropriate voltage setting, connect the probes to the output terminals of the adapter, and check if the voltage matches the specifications on the adapter label. If the voltage is significantly different or the adapter shows no output, it may be faulty and should be replaced.