220-1101 Question 307
Single answerModular power supplyA technician is building a custom desktop for a video editor using a fully modular ATX power supply. The system powers on, fans spin, and the motherboard LEDs light up, but the computer will not POST. The technician confirms the 24-pin motherboard connector is attached correctly. Which action should the technician perform NEXT to most likely resolve the issue?
- A
Connect the 4/8-pin CPU power cable from the power supply to the motherboard's CPU power connector near the processor socket
- B
Replace the modular power supply with a non-modular unit because modular models are less compatible with custom builds
- C
Move the existing PCIe power cable from the graphics card to the motherboard's CPU power connector because the connectors are electrically interchangeable
- D
Install additional SATA power cables to improve overall power delivery to the motherboard
Show answer and explanation
Correct answer: A
Explanation
In real-world PC assembly, especially with modular and fully modular power supplies, the technician must choose and install each required cable individually. The 24-pin ATX motherboard cable alone is not sufficient for most modern systems. The separate CPU power cable, commonly a 4-pin, 8-pin, or 4+4 EPS connector, must also be connected to the motherboard near the CPU socket. A system may appear partially powered because standby power is present, yet it will fail POST if the CPU does not receive proper power. As a best practice, technicians should verify all required motherboard, CPU, GPU, and drive power connections before replacing parts. Another important best practice is to use only the modular cables designed for that exact PSU model or manufacturer-approved replacements, because modular-side pinouts are not universally standardized.
- A. Correct.
Correct. A very common cause of a no-POST condition in a newly built PC is that the main 24-pin ATX connector is installed, but the separate 4-pin or 8-pin EPS/CPU power connector near the CPU socket is missing. In a modular power supply build, this cable must be selected and connected separately. The motherboard may still show standby lights and some fans may spin without the CPU power cable, but the processor will not initialize properly, preventing POST.
- B. Incorrect.
Incorrect. Modular power supplies are standard and widely compatible when used correctly. Their key characteristic is detachable cabling, which improves cable management and airflow. The issue in this scenario is more likely a missing required power connection than an inherent compatibility problem with modular PSUs.
- C. Incorrect.
Incorrect. PCIe power cables and CPU/EPS power cables may look similar and can both be 6+2 or 4+4 style components depending on the connector type, but they are not interchangeable. Their pinouts differ, and using the wrong cable or connector can prevent booting or even damage components. This option reflects a dangerous misconception about modular power supply cabling.
- D. Incorrect.
Incorrect. SATA power cables provide power to storage devices and some accessories, not the CPU power circuitry on the motherboard. Adding SATA power will not resolve a missing CPU power connection or a no-POST issue related to processor initialization.