Hardware and Network Troubleshooting

A technician is working at a user's desk when the desktop PC suddenly emits a sharp burning smell along with a faint crackling sound, and a thin wisp of smoke rises from the rear of the case near the power supply. What should the technician do FIRST?

A workstation that has been in service for six years now randomly locks up and sometimes fails to POST. During a visual inspection, a technician notices several small cylindrical components near the CPU socket have domed, bulging tops with brownish residue leaking from the vents. What is the MOST likely cause of the instability?

A user reports that text and images on their newly connected external monitor appear blurry and stretched, and everything looks slightly fuzzy. The monitor works, colors are correct, and there is no flickering. You confirm the monitor is a 2560x1440 native panel, but Windows display settings currently show it running at 1920x1080. What is the MOST likely cause of the blurry appearance?

A user reports that their laptop's touchscreen registers phantom taps and swipes even when no one is touching it, causing apps to open and menus to scroll on their own. The behavior started after the device was left in a hot car. A technician confirms the issue persists in Safe Mode and after a reboot. Following the CompTIA troubleshooting methodology, what is the MOST likely cause?

A user reports that their laptop runs fine for the first hour of use but then abruptly shuts down without warning, especially during video calls and while running spreadsheets. The fan becomes very loud before the shutdown, and the underside of the chassis feels extremely hot near the vents. The battery health reads normal and the AC adapter tests good. Which action is MOST likely to resolve the issue?

A user reports that their laptop powers on normally—the power LED is lit, fans spin, and the keyboard backlight is on—but the built-in screen stays completely black. A technician connects an external monitor via HDMI and the desktop displays perfectly at full resolution. What is the MOST likely cause of the blank built-in display?

A user reports that their laptop's built-in display works fine most of the time, but the image flickers, distorts, or briefly goes black whenever they adjust the screen angle or the laptop is bumped. When the lid is held at certain angles, the display is perfectly stable. An external monitor connected to the laptop shows no problems at any time. Which component is the MOST likely cause?

A technician is troubleshooting a laptop that fails to POST after a memory upgrade. The laptop has two SO-DIMM slots, both now populated with new modules. The technician suspects one of the new modules is defective but wants to confirm which one before ordering a replacement. Following the CompTIA troubleshooting methodology, what is the BEST next step to test the theory?

A user reports that their laptop has recently become extremely slow to boot and applications hang during use. A technician confirms the symptoms and reviews the SMART data, which shows a high reallocated sector count and rising read error rate. According to the CompTIA troubleshooting methodology, what is the technician's NEXT step after gathering this information?

A user reports that a desktop's ink from a laser printer prints fine on the first page but every subsequent page in a long job comes out progressively lighter, and near the end pages are almost blank. Replacing the paper tray and running a cleaning cycle does not help. Which component is the MOST likely cause?

A user reports that their laptop's display shows faint horizontal bands and occasionally flickers, but only after the machine has been running for about 30 minutes. When cold, the screen is perfectly clear. An external monitor connected to the laptop never shows any bands or flickering, even after hours of use. Which component is the MOST likely cause?

A user reports that a laser printer regularly pulls multiple sheets of paper through at once, sometimes jamming and other times printing several blank pages after each job. You inspect the paper tray and confirm the paper is fresh, dry, and properly fanned. What is the MOST likely cause of this behavior?

A user reports that documents from an office laser printer are printing uniformly faded across the entire page. You replace the toner cartridge with a brand-new one and print a test page, but the output is still light and washed out everywhere. The imaging drum was recently replaced and shows no scratches. What is the MOST likely cause?

A user reports that every page from the office laser printer shows a faint duplicate of the previous image repeating further down the page. The primary printed content is otherwise crisp and correctly positioned. What is the MOST likely cause?

A user reports that their LCD monitor shows a single vertical line of pixels that stays the same color regardless of what is displayed on screen. Rebooting, updating the video driver, and connecting the monitor to a different computer with a known-good cable all produce the same vertical line in the exact same position. What is the MOST likely cause?

A technician replaced a faulty DisplayPort cable on a user's second monitor, which now displays correctly. Before leaving the workstation, the technician wants to complete the correct next step in the CompTIA troubleshooting methodology. What should the technician do?

A user reports that a shared laser printer suddenly began producing pages filled with random characters, symbols, and stray text instead of the documents they send. The printer prints its internal test/config page perfectly, and other users on a different print server print to it without issues. What is the MOST likely cause?

A conference room projector has been in service for over three years. Users report that the image has become noticeably dim over the past few weeks, and an on-screen warning about lamp hours appeared at startup. The image is otherwise focused, correctly aligned, and shows accurate colors. What is the MOST likely cause?

A conference room projector powers on normally and displays an image, but after roughly 20 minutes it shuts off on its own. When a technician tries to power it back on immediately, the lamp indicator blinks red and the unit refuses to start until several minutes have passed. What is the MOST likely cause?

A conference room DLP projector has recently started showing brief flashes of red, green, and blue streaks across the image, accompanied by a faint rattling sound from inside the unit. The image is otherwise sharp and correctly aligned. The technician has already verified the source cable and confirmed the same behavior occurs with multiple input devices. Which component is the MOST likely cause of this symptom?