Question

you are testing the power supply in a pc - system by measuring the voltage on the 12 v rail using a multimeter. the voltage is registering as + 12.1 volts. what should you do?
nothing, the power supply is working normally.
replace the power supply.
disconnect all devices that are drawing power from the power supply before testing it.
switch the voltage selector on the back from 220 vac to 110 vac.
i want to review this question later. (optional)

Explanation:

A PC power - supply's 12V rail with a reading of 12.3 volts is within an acceptable tolerance range for normal operation. So no action is needed.

Answer:

Nothing, the power supply is working normally.