220-1101 Question 109
Single answerAA technician is replacing the motherboard in a small office desktop used for basic accounting tasks. After installing the new board, the system powers on, all fans spin, and the power LED lights up, but there is no video output and the system does not complete POST. The technician confirms the monitor works on another PC and the graphics card is seated correctly. Which action should the technician perform FIRST to resolve the issue?
- A
Verify that the 24-pin ATX power connector and the 4/8-pin CPU power connector are both attached to the motherboard
- B
Replace the monitor cable with a higher-speed HDMI cable
- C
Install additional RAM to improve POST compatibility
- D
Update the motherboard BIOS using the operating system installer
Show answer and explanation
Correct answer: A
Explanation
In A+ Core 1 troubleshooting, technicians should start with the most likely and least invasive checks after hardware replacement. For a motherboard swap, confirming all required power connections is critical, especially the separate CPU power connector in addition to the 24-pin ATX connector. Systems may appear to power on because fans and LEDs receive power, yet still fail POST if the CPU is not powered correctly. This aligns with standard motherboard installation best practices from system board and PSU documentation provided by manufacturers such as ASUS, Gigabyte, MSI, Dell, and HP, which consistently identify both motherboard and CPU power connections as required for successful startup.
- A. Correct.
Correct. A very common cause of a system powering on but failing to POST after a motherboard replacement is that the main 24-pin motherboard power connector is attached but the separate 4-pin or 8-pin CPU power connector is missing. In that case, fans and LEDs may work, but the CPU cannot initialize properly, resulting in no display and no successful POST. Checking motherboard power connections is one of the first hardware verification steps in a no-POST scenario.
- B. Incorrect.
Incorrect. If the monitor already works on another computer, replacing the cable is not the first or most likely fix in this scenario. A bad cable can cause no display, but it would not explain a failure to complete POST after a motherboard replacement as directly as a missing motherboard power connection would.
- C. Incorrect.
Incorrect. Adding more RAM is not an appropriate first step. A system can often POST with a single properly seated compatible RAM module. While improperly seated or incompatible RAM can cause no-POST symptoms, the scenario points to a recent motherboard replacement, making incomplete power connection verification a higher-priority and more likely issue.
- D. Incorrect.
Incorrect. You cannot normally update the BIOS from an operating system installer when the system is not completing POST and displaying no video. BIOS updates may address compatibility problems in some cases, but they are not the first troubleshooting step when basic power and POST-related hardware checks have not yet been confirmed.