220-1101 - Hardware and Network Troubleshooting (29% of the exam) - Section 5.2

Troubleshoot problems related to motherboards, RAM, CPU, and power, including POST codes, no-power and overheating symptoms, in a given scenario.

Diagnose core component failures from their symptoms - no power or POST, continuous reboots, BIOS time and setting loss (a failing CMOS battery), burning smells, and overheating shutdowns - and read POST beep codes and diagnostic LEDs. Distinguish a RAM fault (random crashes, blue screens) from a CPU or power-supply fault, and verify with appropriate tools such as a power-supply tester or multimeter.

POST beep codesCMOS batteryOverheating shutdownPower-supply tester

Practice question for this objective

Free sampleHardware and Network Troubleshootinghard

A technician presses the power button on a workstation and nothing happens: no fans spin, no LEDs light, and there are no POST beeps. The wall outlet and the power cable have already been confirmed good on another device. What is the best next step to isolate the fault?

AReplace the motherboard, because the absence of any POST beeps proves the board itself is dead.
BReseat the RAM and clear the CMOS to force the system to run a fresh power-on self-test.
CSwap the CPU with a known-good processor to rule out a failed chip as the root cause.
DTest the power supply rails with a power-supply tester before swapping any other components. Correct

For a completely dead PC with mains confirmed good, verify the power supply with a tester before replacing motherboard, RAM, or CPU. A no-power symptom (no fans, no LEDs, no beeps) most often traces to the power supply; a PSU tester checks each rail against spec quickly and non-destructively, letting the technician confirm or eliminate the likeliest cause before committing to costlier component swaps.

Why A is wrong: No beeps can suggest a board fault, so this is tempting, but a dead PSU produces the identical no-beep symptom, and swapping the board first is expensive and skips the obvious upstream check.

Why B is wrong: Reseating RAM and clearing CMOS help with POST failures, but here the system gets no power at all, so there is no POST to influence and the step diagnoses nothing.

Why C is wrong: A dead CPU can stop a system, making this seem thorough, but a totally unpowered board with no fans points upstream to power delivery, and pulling the CPU first is slow and out of order.

Why D is correct: Correct. With a completely dead system and mains already proven good, verifying the PSU outputs with a tester is the cheapest, fastest way to confirm or clear the most probable cause before touching costlier parts.

See more 220-1101 practice questions, answers explained.

Exam traps in Hardware and Network Troubleshooting

Answers that look right on this material and are not. Each one is a distractor from a different question in the 220-1101 bank for this domain.

Replace the CPU, since a no-video POST failure points to a dead processor.
Why it is wrong: A dead CPU can stop POST before video, which is tempting, but the beep code specifically flags memory, so the processor is not the indicated fault to act on first.
The system firmware is corrupt and must be re-flashed to a newer version to hold its settings.
Why it is wrong: Corrupt firmware is a tempting guess for lost settings, but a corrupt BIOS would usually block POST entirely, and here the machine boots normally and only loses config after mains power is removed.
Update the motherboard BIOS from a USB drive to add compatibility for the new memory module.
Why it is wrong: A BIOS update can improve memory support, which makes it tempting, but with no video output there is no way to reach the firmware update tool, and the beep pattern already signals a memory fault to address first.

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