Hardware Assembly, Maintenance and Troubleshooting
What this domain tests
Systematic assembly, preventive maintenance and a logical fault-finding sequence. Questions often give a symptom and ask for the next best test rather than a random part swap.
Rules
- Work on a grounded mat with a wrist strap. Fit the CPU, cooler and RAM before mounting the motherboard; connect the 24-pin ATX and 4/8-pin CPU power, then front-panel headers.
- First power-on: check fans, listen for POST beeps and watch for a display. No display with fans running suggests RAM, graphics or monitor signal; repeated beeps often indicate memory.
- Troubleshoot in order: visual inspection for bulging capacitors, burnt smell or loose cables, then power rails, connections, substitution with a known-good part, and signal tracing.
- Half-split method: test at the midpoint of a signal path to halve the search area.
- Preventive maintenance: clean dust, check fan operation, reseat connectors, back up data, update firmware only when needed, and record changes.
- Do not repair power-supply internals unless trained; capacitors hold charge.
Worked example
A desktop powers on but shows no image. Confirm the monitor is on the correct input and the cable is seated. Listen for beep codes; if the board beeps repeatedly, power off, reseat the RAM and try one stick in the first slot. If there is still no image, substitute a known-good graphics card or use onboard video. Only then suspect the motherboard. Each step tests one variable.
Traps
- Replacing parts before checking power and cabling.
- Changing several things at once, so the cause is unknown.
- Ignoring ESD precautions while handling boards.
- Assuming a lit power LED means the supply is healthy.