CompTIA A+ Core 1 (220-1201)Hardware and Network TroubleshootingHard
A technician is troubleshooting a desktop computer that fails to boot. When powered on, the system lights up, fans spin, but there is no video output, and no POST beeps are heard. The technician has already reseated the RAM and video card. Which of the following components is MOST likely causing the issue?
- AA faulty power supply unit (PSU)
- BA failing hard drive
- CA corrupted operating system
- DA dead CPU or motherboard
Show answer & explanationAnswer & explanation
Correct answer: D. A dead CPU or motherboard
If the system powers on (lights, fans), but there's no video and no POST beeps after reseating RAM and video, it indicates a critical failure before or during the initial POST sequence. This points to either a dead CPU (which prevents POST from even starting) or a dead motherboard (which coordinates all POST activities and component power).
Why the other options are wrong
- A. A faulty PSU would likely result in no power at all, or intermittent power, not consistent power with fans/lights but no POST/video.
- B. A failing hard drive would allow POST to complete and some video output, but would then result in a boot error like 'No Boot Device Found'.
- C. A corrupted operating system would occur after POST and video output, leading to boot errors or crashes, not a complete lack of POST beeps and video.
No POST, No Video, Fans Spin
When a computer powers on (fans, lights) but has no video output and no POST beeps, even after reseating RAM/GPU, it strongly indicates a failure of the CPU or motherboard, as these are critical for initiating the power-on self-test.
- Power present, but no boot sequence
- RAM/GPU ruled out
- CPU and motherboard are core for POST
- Often requires component replacement
Memory trick: CPU or Motherboard: Core Parts are Broken.