220-1201 That their computer does not power on at all Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Replace the CMOS battery.

  Why it's wrong here

  A dead CMOS battery primarily causes the system to lose its BIOS/UEFI configuration, such as date, time, and boot order, when power is removed. While this can lead to boot issues or errors, it does not prevent the power supply unit (PSU) from receiving power or the motherboard from initiating the power-on sequence, which would typically involve fans spinning and indicator LEDs illuminating. The complete lack of any power activity indicates a more fundamental power delivery problem, not a CMOS battery failure.

• ✓

  Check if the power supply's on/off switch is set to the '1' (on) position.

  Why this is correct

  The power supply unit (PSU) often includes a physical on/off switch on its rear panel, typically marked '0' for off and '1' for on. If this switch is in the '0' (off) position, it completely interrupts the flow of AC power from the wall outlet to the PSU's internal components, preventing any DC power from being delivered to the motherboard or other system components. This simple oversight is a common cause of a computer appearing completely dead, making it the most logical and immediate troubleshooting step to verify primary power delivery.

• ✗

  Reseat the RAM modules.

  Why it's wrong here

  Issues with Random Access Memory (RAM), such as improper seating or module failure, typically manifest after the power supply unit (PSU) has successfully initiated power to the motherboard. Common symptoms include the system powering on (fans spin, LEDs light up) but failing to display video, or the motherboard emitting specific beep codes indicating a memory error. A complete absence of any power activity, including no fan spin or LED illumination, indicates a problem upstream of the RAM, specifically with the primary power delivery system.

• ✗

  Test the PSU with a multimeter.

  Why it's wrong here

  Testing the PSU with a multimeter is incorrect because the scenario describes a complete lack of power—no fans or LEDs—which points to a primary power failure, not a voltage-rail issue. A multimeter checks specific output voltages (e.g., +12V, +5V) but cannot verify the PSU’s ability to deliver the correct power-good signal or handle load. This option is tempting because a multimeter is a standard tool for diagnosing faulty PSUs when the system partially powers on (e.g., fans spin briefly then stop), where measuring rail voltages would isolate a failed component.