220-1101 Question 389
Single answerNo powerA technician is troubleshooting a desktop PC that will not power on after being moved to a different office. Pressing the power button produces no lights, no fans, and no beep codes. The monitor powers on normally, and the wall outlet is known to work because a lamp functions when plugged into it. The technician confirms the power cable is firmly connected to the back of the PC. Which of the following should the technician check NEXT?
- A
Verify the power supply's rear voltage selector is set correctly for the local power standard
- B
Replace the CPU because a failed processor commonly causes a complete no-power condition
- C
Reseat the RAM modules because memory issues prevent the system from receiving power
- D
Update the BIOS using the motherboard manufacturer's latest firmware
Show answer and explanation
Correct answer: A
Explanation
The best next step is to verify the PSU's rear voltage selector is set correctly for the local electrical standard, if the power supply has one. In CompTIA A+ Core 1 troubleshooting, a true no-power condition should be approached from the outside in: verify the power source, confirm cabling, check external switches and PSU settings, and then test internal components only after basic power delivery has been ruled out. A moved PC is a classic scenario where a rear PSU switch or 115V/230V selector may have been changed accidentally. This aligns with standard vendor and field-service best practices: confirm AC source, PSU configuration, and physical connections before replacing internal hardware.
- A. Correct.
This is correct. On power supplies that include a manual 115V/230V selector, an incorrect setting can prevent the system from powering on and may damage the PSU when connected to the wrong input voltage. After a move, this is a realistic next check once the outlet and power cable have been verified. In basic no-power troubleshooting, technicians should confirm external power, cable connections, and PSU input settings before moving to more invasive internal component checks.
- B. Incorrect.
This is incorrect. A failed CPU is far less likely to cause a true no-power symptom than a power delivery issue. With a no-power condition, the technician should first verify AC input, PSU settings, PSU switch position, front-panel connections, and power supply function. CPU failures more often appear as a no-POST or no-boot issue rather than no lights and no fan activity at all.
- C. Incorrect.
This is incorrect. Improperly seated RAM can prevent POST and may cause beep codes or diagnostic LEDs, but it does not typically stop all power activity. In this scenario there are no signs of any power reaching the system, so memory is not the best next troubleshooting step.
- D. Incorrect.
This is incorrect. A BIOS update is not an appropriate first response to a no-power issue. Firmware updates are used to address compatibility, stability, or known hardware support issues when the system can power on sufficiently to perform the update. They do not resolve a basic lack of electrical power to the system.