220-1101 Question 268
Single answerHeadersA technician is assembling a custom desktop PC and needs to connect the front-panel cables from the case to the motherboard. The case has leads labeled PWR SW, RESET SW, HDD LED, and PLED. The motherboard manual refers to these as the system panel header. Which of the following should the technician do FIRST to avoid damaging components or miswiring the front-panel connections?
- A
Match each case lead to the pinout shown in the motherboard manual for the front-panel header
- B
Connect all front-panel leads in any open motherboard header until the system powers on
- C
Attach the PWR SW lead to a USB header because both use small pin connectors
- D
Install the HDD LED lead without checking polarity because LEDs function the same in either direction
Show answer and explanation
Correct answer: A
Explanation
On A+ Core 1, headers commonly refer to motherboard connection points for internal components and case wiring, including front-panel headers, USB headers, audio headers, and fan headers. In this scenario, the technician is working specifically with the system panel header, which is used for case buttons and indicator LEDs. The correct action is to verify the motherboard's documented pinout before connecting anything, because header layouts are not standardized in the same physical arrangement across all boards. Manufacturer documentation and motherboard silkscreen labels are the best references. Best practice also includes observing polarity for LED connections and avoiding forced connections into unrelated headers such as USB or audio headers.
- A. Correct.
Correct. Front-panel case connectors such as power switch, reset switch, power LED, and drive activity LED must be connected to the correct motherboard front-panel header pins as documented by the motherboard manufacturer. Using the motherboard manual or the silkscreen label on the board is the proper first step because header layouts vary by manufacturer and model.
- B. Incorrect.
Incorrect. Randomly trying open headers is poor practice and can lead to nonfunctional controls, incorrect LED behavior, or possible damage if the wrong header is used. A+ best practice is to identify the correct header and pinout before making connections.
- C. Incorrect.
Incorrect. A USB header and a front-panel system header are different interfaces with different pin assignments and voltages. Although the connectors may appear similar in size, they are not interchangeable. This reflects a common misconception that any small motherboard header can accept any small case lead.
- D. Incorrect.
Incorrect. LED leads are polarity-sensitive. While the power switch and reset switch typically are not polarity-sensitive, HDD LED and power LED leads usually must be connected with the correct positive and negative orientation to function properly. Skipping the polarity check may result in the LED not lighting.