220-1101 Question 400
Single answerLight-emitting diode (LED) status indicatorsA technician is troubleshooting a desktop PC that will not complete POST. When the power button is pressed, the fans spin, the screen stays black, and the front-panel power LED flashes amber in a repeating pattern. The technician wants to identify the failed component as quickly as possible before replacing parts. Which action should the technician take FIRST?
- A
Consult the computer manufacturer's service manual to interpret the LED blink code for that specific model
- B
Replace the power supply because an amber LED always indicates insufficient wattage
- C
Reseat the CPU because any repeating LED pattern indicates a processor fault
- D
Clear the TPM and reset BIOS security settings because POST failures are commonly caused by encryption hardware
Show answer and explanation
Correct answer: A
Explanation
A+ Core 1 expects technicians to use built-in diagnostic indicators, including LEDs and beep codes, as part of a structured troubleshooting process. The key applied skill here is recognizing that front-panel LEDs often provide model-specific POST diagnostics. Best practice is to verify the exact meaning of the blink or color pattern in the manufacturer's documentation before swapping parts. Major vendors such as Dell, HP, and Lenovo publish service manuals and support articles that map LED patterns to likely hardware failures. This approach saves time, avoids unnecessary replacements, and follows standard troubleshooting methodology: identify the problem, establish a theory based on evidence, test the theory, and then plan corrective action.
- A. Correct.
Correct. LED status indicators and blink codes are vendor-specific on many desktops and laptops. A flashing amber power LED can indicate different failures depending on the manufacturer and model, such as memory, power, motherboard, or CPU issues. The best first step is to consult the manufacturer's service documentation or hardware maintenance manual to decode the pattern accurately before replacing components.
- B. Incorrect.
Incorrect. Amber LEDs are not a universal indicator of insufficient wattage or a failed power supply. Some systems use amber, white, green, or combinations of colors and blink sequences to report different POST or hardware faults. Replacing the power supply without first interpreting the vendor's LED code would be premature and may not resolve the problem.
- C. Incorrect.
Incorrect. A repeating LED pattern does not universally indicate a CPU problem. On many systems, blink patterns can point to RAM, motherboard, GPU, or power-related issues. Reseating the CPU first is a common guess, but it is not the most efficient or evidence-based first action when the system provides a diagnostic LED pattern.
- D. Incorrect.
Incorrect. TPM or BIOS security settings are not the most likely first cause to investigate in this scenario, especially when the system is presenting a hardware-status LED code during POST. Clearing security settings without understanding the LED pattern could create additional issues and does not align with standard hardware troubleshooting practice.