Question 1

Laser printer safety: While servicing a laser printer, which component should you avoid touching because it operates at high temperature during printing?

Accepted Answer

Introduction / Context: Laser printers fix toner to paper by heat and pressure. Safety awareness is crucial during maintenance to avoid burns and equipment damage. Given Data / Assumptions: We are working on a standard office laser printer. The printer has recently been operating, so internal components may be hot. Technician must know which parts are hazardous to touch. Concept / Approach: The fuser assembly contains heated rollers that reach high temperatures to melt toner and bond it to paper. Immediately after printing, the fuser is very hot. While the high-voltage power supply and corona assemblies are electrically dangerous, the thermal hazard is specifically the fuser. Step-by-Step Solution: Identify the function of the fuser: heat and pressure for toner fixing.Recognize it operates at high temperature during and after print jobs.Select “fuser” as the hot component to avoid touching. Verification / Alternative check: Service manuals warn about fuser temperature and recommend cooldown time. Temperature sensors (thermistors) and thermal fuses on the fuser underline the heat risk. Why Other Options Are Wrong: Printer head: Not used in laser printers (inkjets use printheads). Primary corona: High voltage risk, but not the primary heat hazard. High-voltage power supply: Electrical hazard, not typically hot to the touch. None of the above: Incorrect because the fuser is correct. Common Pitfalls: Opening the fuser immediately after heavy printing; touching the roller surface; ignoring lockout/tagout and ESD protocols while servicing. Final Answer: fuser

Question 2

Telecom basics: Integrated Services Digital Network (ISDN) uses which signal technology for bearer channels?

Accepted Answer

Introduction / Context: ISDN was designed to carry voice and data over the public network using a digital end-to-end architecture. Knowing whether the bearer channels are digital or analog is fundamental for configuring terminal adapters and PBX interfaces. Given Data / Assumptions: ISDN Basic Rate Interface (BRI) and Primary Rate Interface (PRI) are considered. Bearer channels (B channels) carry user information. Signaling occurs on a D channel, also digital. Concept / Approach: ISDN provides digital signaling and digital bearer channels. Even voice is encoded digitally on B channels. Although ISDN lines may traverse analog segments deeper in the carrier plant historically, the service interface to the customer is digital. Therefore, the accurate choice is “only digital.” Step-by-Step Solution: Identify ISDN B and D channels as digital channels.Note that user equipment interfaces via digital framing and coding.Choose “only digital.” Verification / Alternative check: Standards (e.g., ITU-T I.430/I.431) define the electrical and framing properties of ISDN as digital interfaces, confirming the answer. Why Other Options Are Wrong: Digital and analog / only analog / neither: Contradict the digital nature of ISDN interfaces. Mostly digital: Hedging phrase; ISDN is defined as digital at the interface. Common Pitfalls: Confusing ISDN with analog POTS lines or with DSL variants; assuming “digital phone service” must be VoIP—ISDN predates IP telephony and is circuit-switched digital. Final Answer: only digital

Question 3

ISA device configuration: When configuring a new ISA network interface card, which of the following is a valid hexadecimal I/O base address?

Accepted Answer

Introduction / Context: Legacy ISA network adapters required manual selection of I/O base addresses and IRQs. Recognizing valid and non-conflicting addresses prevents resource clashes with serial, parallel, and other devices. Given Data / Assumptions: Hexadecimal notation without the H suffix is implied by context. Typical ISA NIC addresses include 300, 320, 340, 360, etc. Common reserved ports: COM1 3F8, COM2 2F8, LPT1 378. Concept / Approach: To avoid conflicts, choose an address not already used by standard ports. 378 is the default for LPT1; 3F8 and 2F8 are defaults for COM1 and COM2. 360 is a classic free range used by many ISA network cards. Therefore, 360 is the valid choice in this set for a NIC. Step-by-Step Solution: Eliminate 3F8 (COM1) and 2F8 (COM2) due to conflicts.Eliminate 378 (LPT1) due to conflict.Select 360 as a standard NIC I/O base address. Verification / Alternative check: Vendor jumpers/manuals list 300–3E0 ranges; OS hardware listings show NICs at 300/320/340/360 without clashes. Why Other Options Are Wrong: 378: Parallel port base; would break printing or the NIC. 2F8 / 3F8: Serial port bases; would break COM ports or the NIC. None of the above: Incorrect because 360 is valid. Common Pitfalls: Forgetting that ranges include multiple consecutive ports (e.g., 360–36F); neglecting to align IRQ and DMA settings; assuming PnP will auto-resolve on pure ISA hardware. Final Answer: 360

Question 4

Video memory sizing: How much video RAM is required to support a resolution of 1024 × 768 at 24-bit true color (no overlays or extra buffers)?

Accepted Answer

Introduction / Context: Sizing video memory for a given resolution and color depth is a classic calculation. Even though modern GPUs have abundant VRAM, understanding the framebuffer requirement remains useful for embedded systems, thin clients, and legacy hardware. Given Data / Assumptions: Resolution: 1024 × 768 pixels. Color depth: 24 bits per pixel (true color), which equals 3 bytes per pixel. Only a single framebuffer is considered (no double buffering, Z-buffer, or textures). Concept / Approach: Video memory required for a single framebuffer equals pixel_count * bytes_per_pixel. Compute pixel_count, multiply by 3 bytes, then convert bytes to megabytes. Choose the smallest offered VRAM size that meets or exceeds this requirement from the options provided. Step-by-Step Solution: Compute pixels: 1024 * 768 = 786,432 pixels.Bytes per pixel at 24-bit: 3 bytes.Required bytes: 786,432 * 3 = 2,359,296 bytes.Convert to MB (1 MB = 1,048,576 bytes): 2,359,296 / 1,048,576 ≈ 2.25 MB.Select the next standard size ≥ 2.25 MB from options: 4MB. Verification / Alternative check: Older graphics cards offering 2 MB could not do 1024 × 768 at 24-bit; cards with 4 MB were commonly specified for this mode, confirming the selection. Why Other Options Are Wrong: 512KB / 1MB: Insufficient for the 2.25 MB requirement. 8MB: Works but is not the minimum required from the set; the question expects the adequate choice. None of the above: Incorrect because 4MB meets the need. Common Pitfalls: Confusing bits with bytes; forgetting overhead for additional buffers (which would further increase the requirement); assuming decimal megabytes instead of binary in legacy specs. Final Answer: 4MB

Question 5

Electronics recycling — Among common PC components, which item is generally the easiest to recycle responsibly through manufacturer take-back or office supply programs?

Accepted Answer

Introduction / Context: Troubleshooting skills extend beyond repair. Responsible end-of-life handling of parts protects the environment and meets regulatory expectations. Knowing which components can be most readily recycled helps technicians advise customers and set up green workflows. Given Data / Assumptions: We are comparing routine PC parts returned from offices: motherboards, CMOS batteries, toner cartridges, and CRTs. “Easiest to recycle” means widely accepted by retail/office programs with clear, low-friction logistics. We are not analyzing specialized industrial channels, only typical end-user options. Concept / Approach: Toner cartridges have mature collection ecosystems (drop-off bins, mail-back labels, and vendor take-back). In contrast, motherboards require e-waste facilities, CMOS batteries are hazardous and require special bins, and CRTs are regulated due to leaded glass, imposing fees and strict handling. Step-by-Step Solution: List common recycling pathways for each item.Identify availability and friction: toner programs are ubiquitous and simple; others require specialized e-waste streams.Conclude that toner cartridges are the easiest item to recycle in everyday practice. Verification / Alternative check: Major printer manufacturers and office retailers routinely provide prepaid labels and in-store bins for toner cartridges, confirming their convenience relative to other components. Why Other Options Are Wrong: Motherboards: contain mixed materials and require certified e-waste processing. CMOS batteries: considered hazardous waste; need battery-specific collection. CRTs: heavy, hazardous, tightly regulated; rarely “easy.” “None of the above” ignores the widespread cartridge programs. Common Pitfalls: Throwing cartridges in trash, shipping without caps (spills), or mixing batteries with general recyclables. Always follow vendor instructions. Final Answer: Toner cartridges.

Question 6

Windows 95 startup behavior — What file extension does Windows 95 use for its automatic backup copy of the Registry at startup?

Accepted Answer

Introduction / Context: Understanding legacy Windows startup files is useful when recovering older systems or studying OS history. Windows 95 maintained Registry data and created backup copies during startup for recovery. Given Data / Assumptions: Platform: Microsoft Windows 95 (pre-ScanReg daily .cab backups used by later versions). Registry core files include System.dat and User.dat. Question concerns the extension of the startup backup copy. Concept / Approach: Windows 95 creates fallback copies of Registry hives using a conventional backup extension. While the active hives use .dat, backups are commonly stored using the .bak extension to indicate a restorable previous state. Step-by-Step Solution: Identify the active hive files: System.dat and User.dat.Recall the conventional Windows 9x backup convention: .bak for prior copies.Select the extension used for the startup backup: .bak. Verification / Alternative check: Legacy troubleshooting guides and Windows 95 references describe replacing corrupted .dat files with their .bak counterparts when repairing the system. Why Other Options Are Wrong: .dat are active Registry files, not the backup extension. .dao and .tmp are unrelated; “None of the above” is incorrect because .bak is correct. Common Pitfalls: Confusing Windows 95 behavior with Windows 98/ME ScanReg .cab restore points; assuming .tmp holds reliable backups. Final Answer: .bak.

Question 7

PC protection during lightning storms — What is the best immediate way to protect a running PC and modem at home when a thunderstorm develops at night?

Accepted Answer

Introduction / Context: Lightning-induced surges can enter through power and telecom lines. While protective devices reduce risk, the most certain way to prevent damage in a live storm is complete physical isolation from those conductors. Given Data / Assumptions: Home user with a PC and dial-up or DSL modem connected to phone line. Thunderstorm is active; immediate action is sought. Goal: minimize risk to equipment and safety. Concept / Approach: Surge suppressors help, but a direct or nearby strike can exceed their ratings. Removing conductive paths (mains plug and telephone line) is the definitive protection because it prevents surge energy from coupling into the equipment. Step-by-Step Solution: Shut down the computer gracefully if time allows.Physically unplug the AC mains cord from the outlet.Disconnect the phone or coax line from the modem.Wait until the storm passes before reconnecting and powering up. Verification / Alternative check: Utility and insurer recommendations consistently state that unplugging is the only sure protection against severe surges during lightning events. Why Other Options Are Wrong: Lightning rods protect structures, not individual electronics; surge protectors can be overwhelmed; having protectors on both lines reduces risk but is less certain than physical disconnection; the joke option is non-technical. Common Pitfalls: Unplugging only the power while leaving the modem line connected, which can still channel a damaging surge into the PC. Final Answer: Unplug the PC from mains and disconnect the phone line from the modem.

Question 8

PC hardware — Which chip handles legacy serial (COM) port communications on IBM-PC compatibles?

Accepted Answer

Introduction / Context: PC serial ports (COM1–COM4) use a Universal Asynchronous Receiver/Transmitter (UART) to convert between parallel bus data and serial bit streams. Technicians often need to recognize common UART models and their functions. Given Data / Assumptions: Legacy ISA/PCI systems with standard COM ports. Typical UART model numbers include 8250, 16450, and 16550. Question asks for the device that controls serial communication. Concept / Approach: The 16550 UART introduced FIFO buffering to improve throughput and reduce CPU interrupts, becoming the de facto standard for reliable serial communication on PCs. Step-by-Step Solution: Identify the function needed: serializing/deserializing and buffering.Recall standard part: 16550 UART provides hardware FIFOs for COM ports.Confirm that BIOS and CPU do not directly perform this low-level serialization; DMA823 relates to memory transfers, not UART. Verification / Alternative check: Motherboard and I/O card documentation list 16550 or compatible cores for COM ports. Why Other Options Are Wrong: ROM BIOS initializes hardware but is not the serial hardware engine; the CPU runs drivers but does not replace a UART; DMA823 is unrelated to serial line coding. Common Pitfalls: Confusing DMA controllers with serial controllers, or assuming the BIOS “does the work” beyond initialization. Final Answer: UART 16550.

Question 9

Hard-drive care — Which of the following is a valid preventative maintenance task for a hard drive in everyday support practice?

Accepted Answer

Introduction / Context: Preventative maintenance reduces downtime and data loss. For modern HDDs and SSDs, practical tasks focus on monitoring health and filesystem integrity rather than invasive mechanical adjustments. Given Data / Assumptions: Typical office PCs with either HDDs or SSDs. Routine admin privileges available. Goal: realistic tasks that improve reliability. Concept / Approach: Valid preventative actions include checking SMART attributes, running vendor diagnostics, scanning for bad sectors (HDDs), and verifying the filesystem. Mechanical “head alignment” is a legacy lab procedure, not field maintenance on sealed drives. Step-by-Step Solution: Schedule periodic SMART reviews and vendor diagnostic tests.Run OS file system checks and monitor reallocated/pending sector counts (HDD) or media wear (SSD).Back up critical data proactively when indicators degrade. Verification / Alternative check: Drive vendor tools (e.g., SeaTools, Data Lifeguard) and OS utilities (chkdsk, fsck) are standard in preventative routines. Why Other Options Are Wrong: Head alignment diagnostics: not applicable to sealed modern drives. Initializing (re-partitioning/formatting) regularly risks data loss and is not maintenance. Uninstalling programs is housekeeping, not drive maintenance. Common Pitfalls: Ignoring SMART warnings, skipping backups, and running destructive tests on mission-critical systems during business hours. Final Answer: Disk check diagnostics (surface scan, SMART review, file system check).

Question 10

New CD-RW installed, existing CD-ROM stops working — What should the customer check first on IDE/PATA systems?

Accepted Answer

Introduction / Context: On legacy IDE/PATA channels, two devices share a cable and require proper role assignment. Installing an optical drive with incorrect jumpers often causes both drives to disappear or one to stop functioning. Given Data / Assumptions: System previously worked with a CD-ROM. A new CD-RW was added to the same IDE channel. After installation, the old drive no longer works. Concept / Approach: Each IDE channel supports two devices: one Master and one Slave (or both Cable-Select with a CS-rated cable). Conflicting jumpers or mixing CS with fixed roles breaks device detection by the BIOS/OS. Step-by-Step Solution: Power down and open the case safely.Check the rear jumper block on both optical drives for Master/Slave/CS settings.Match settings appropriately for their positions and the cable type.Reboot and verify both devices enumerate correctly in BIOS and OS. Verification / Alternative check: Motherboard and drive labels/silkscreens show valid jumper configurations; correcting them typically restores operation without firmware changes. Why Other Options Are Wrong: BIOS flashing is unnecessary for simple detection conflicts. CONFIG.SYS is not responsible for hardware enumeration on modern Windows. Adding devices manually rarely fixes physical role conflicts. Common Pitfalls: Leaving both on Master, mixing CS with fixed roles, or using a non-CS cable with CS mode. Final Answer: Verify jumper settings (Master/Slave/Cable-Select) on the new CD-RW.

Question 11

ESD safety — For a conductive ESD workbench/mat, what should it be grounded to for best practice in a typical office/service environment?

Accepted Answer

Introduction / Context: Electrostatic discharge controls rely on a single common, safe reference point so charges bleed away slowly without creating hazardous shock risks. Proper grounding of mats and wrist straps is essential. Given Data / Assumptions: Conductive/antistatic mat on a service bench with a 1 MΩ safety resistor in the ground lead. Standard building wiring with a verified safety ground in the AC outlet. Technician uses a wrist strap connected to the same reference. Concept / Approach: Best practice is to tie the ESD mat and wrist strap to the building’s AC safety ground. This provides a stable, low-impedance reference and ensures all equipment chassis connected to mains share the same ground potential, minimizing differential voltages. Step-by-Step Solution: Attach the mat's ground lead (via 1 MΩ) to the AC outlet's ground prong using an approved ground adapter.Connect the wrist strap to the mat's common point ground.Clip the PC chassis to the same mat ground if desired, ensuring everything shares the same reference. Verification / Alternative check: ESD standards and training materials specify connection to equipment grounding conductors, not to signal grounds or floating metal alone. Why Other Options Are Wrong: Bench-only ground leaves the system floating. Motherboard pins are not a safe tie-point. A chassis that is not tied to building ground can float and create ESD or shock hazards. Common Pitfalls: Bypassing the 1 MΩ resistor, using unverified outlets, or daisy-chaining grounds to random pipes or radiators. Final Answer: AC outlet safety ground.

Question 12

PC resource conflicts — Why are IRQ conflicts historically more common than I/O address conflicts on legacy PCs?

Accepted Answer

Introduction / Context: Legacy ISA/AT hardware required manual configuration of device resources. Understanding why certain conflicts were common helps when supporting older systems and embedded designs that retain similar concepts. Given Data / Assumptions: Environment: ISA/AT-era PCs with fixed IRQ lines and configurable I/O ranges. Devices compete for limited, sharable resources. Plug and Play was limited or absent. Concept / Approach: IRQ lines were a scarce resource (typically 15 usable on AT systems, with several reserved), while I/O address space was much larger and easier to partition to avoid overlap. Therefore, IRQ conflicts were statistically and practically more frequent. Step-by-Step Solution: Count available IRQ lines versus I/O address range size.Note typical “favorite” IRQs used by common devices (e.g., 3/4 for serial, 5/7 for LPT/Sound).Recognize that scarce IRQs led to more frequent contention than broadly spaced I/O blocks. Verification / Alternative check: Old motherboard manuals show limited IRQs and many default claims by popular devices, confirming typical conflicts on installation. Why Other Options Are Wrong: BIOS does manage IRQ routing where possible, but scarcity is the real reason. I/O addresses can and do conflict if misconfigured. Software cannot automatically solve all I/O overlaps on non-PnP systems. Common Pitfalls: Assuming modern PCI/PCIe interrupt sharing rules apply to pure ISA systems; forgetting reserved IRQs (e.g., 2 for cascade). Final Answer: There are far more I/O addresses available than IRQ lines.

Question 13

PC fundamentals — In the term ROM BIOS, what does BIOS stand for?

Accepted Answer

Introduction / Context: BIOS is foundational firmware that initializes hardware and starts the boot process on classic PCs. Expanding the acronym correctly is common knowledge for A+/IT support exams. Given Data / Assumptions: The phrase “ROM BIOS” refers to firmware in read-only memory (or flash). The acronym BIOS is being expanded. Concept / Approach: BIOS expands to Basic Input Output System. It provides low-level routines for device access and performs POST before loading the operating system’s boot code. Step-by-Step Solution: Identify each candidate expansion.Select the historically accurate phrase: Basic Input Output System.Reject distractors with altered wording (“Intuitive,” “Industry,” “Organizational”). Verification / Alternative check: Textbooks and vendor documentation consistently define BIOS as Basic Input Output System. Why Other Options Are Wrong: Options A, B, and D are fabricated expansions; “None of the above” is false because the correct expansion is present. Common Pitfalls: Confusing BIOS (legacy) with UEFI (modern firmware) terminology; both serve similar roles but have different architectures. Final Answer: Basic Input Output System.

Question 14

Modem data transfer — Which transmission method do dial-up modems most commonly use for character data?

Accepted Answer

Introduction / Context: Legacy dial-up modems historically carried serial data over analog phone lines. Knowing whether transmission is synchronous or asynchronous clarifies line coding, framing, and UART behavior. Given Data / Assumptions: Standard external/internal modems attached to COM ports (RS-232). Typical terminal/serial communication with start/stop bits. PPP is a link-layer protocol encapsulated over the serial link. Concept / Approach: Asynchronous serial communication frames each character with start/stop bits. This matches how UARTs and COM ports operate for dial-up access. While some specialized modems support synchronous modes, general PC use is asynchronous. Step-by-Step Solution: Identify the physical layer method used by COM port modems: async serial with start/stop bits.Recognize PPP runs over this link but is a protocol, not the electrical transmission method.Select “Asynchronous” as the correct transmission method. Verification / Alternative check: Serial port settings (8N1, baud) and UART operation confirm asynchronous framing is standard for dial-up PC setups. Why Other Options Are Wrong: Synchronous is less common for PC dial-up; “Timed interval” is not a standard; PPP describes link framing and negotiation layered over the serial method. Common Pitfalls: Confusing physical transmission characteristics with higher-layer protocols; assuming PPP implies synchronous signaling. Final Answer: Asynchronous.

Question 15

Electrical Storm Safety for PCs  During a severe electrical storm, what is the only practical way to totally protect a personal computer from surge and lightning damage?

Accepted Answer

Introduction / Context: Lightning surges and severe utility disturbances can enter a computer through any conductive path. Understanding complete isolation techniques helps protect hardware, data, and connected peripherals during electrical storms. Given Data / Assumptions: A typical PC is connected to mains power, network cabling, phone/DSL, and peripheral cables. Lightning can couple into any connected cable, not just the AC cord. We seek a method that provides total protection, not partial mitigation. Concept / Approach: Total protection requires eliminating all conductive paths for surge energy. While surge protectors and UPS devices reduce many transients, they cannot guarantee safety against a near or direct lightning strike. The most effective approach is full physical disconnection of power and all external signal cables so no path remains for energy to reach the electronics. Step-by-Step Solution: Identify all external connections: AC mains, Ethernet, coaxial, telephone/DSL, USB peripherals with their own power bricks, and printer cables.Recognize that surges can propagate through any of these paths.Choose complete isolation: unplug AC power and disconnect every external cable from the PC and peripherals.Store disconnected cables away from equipment to avoid accidental arcing. Verification / Alternative check: Insurance and safety guidelines consistently note that only full disconnection can be considered total protection during a lightning event. Protective devices reduce risk but do not eliminate it. Why Other Options Are Wrong: Disconnect the AC power cable: Leaves network, phone, or coax paths intact for surges. Use a surge protector: Helpful for typical spikes but not guaranteed for lightning energy. Turn off the AC power: A switch open-circuits but still leaves connected conductors in place. None of the above: Incorrect because full disconnection is listed. Common Pitfalls: Assuming a surge strip or UPS provides absolute protection; ignoring phone/coax lines; forgetting externally powered USB hubs or printers that create additional paths. Final Answer: Disconnect all external cables and power cords

Question 16

AT Command Set: Resetting a Modem  When using the standard AT command set, which command resets the modem to its default profile?

Accepted Answer

Introduction / Context: The classic Hayes-compatible AT command set is still referenced in embedded systems and legacy troubleshooting. Knowing the reset command is useful for clearing unexpected states, restoring defaults, and re-establishing known modem behavior. Given Data / Assumptions: A Hayes-compatible modem accepts text commands prefixed with AT. The task is to reset the modem to a default profile without power cycling. We are not changing serial control signals (like DTR) but issuing a command. Concept / Approach: ATZ is the canonical software reset that loads the stored default profile and re-initializes settings. It is distinct from hardware control signals and other AT commands that query or set parameters. Using ATZ is a quick, non-disruptive way to standardize the modem state. Step-by-Step Solution: Open the serial session with correct COM port and baud rate.Enter AT to verify OK response (link working).Issue ATZ to reset the modem and load defaults.Optionally send ATI or AT&V to query identity and current profile. Verification / Alternative check: After ATZ, most modems respond with OK and revert to default settings. If persistent profiles are used (AT&F or AT&Y), behavior can be confirmed by printing active settings. Why Other Options Are Wrong: ATR: Not the standard reset command. DTR: A hardware serial control line (Data Terminal Ready), not an AT text command. DCE: Refers to the device role (Data Communication Equipment), not a command. None of the above: Incorrect because ATZ is valid. Common Pitfalls: Confusing ATZ with AT&F (factory defaults). ATZ loads the stored profile; AT&F loads factory defaults. Both may be used in sequence if required. Final Answer: ATZ

Question 17

Preventing Overheating in Desktop PCs  Which action best helps prevent a computer from overheating during normal operation?

Accepted Answer

Introduction / Context: Thermal management in desktop PCs depends on designed airflow through specific intake and exhaust paths. Correct chassis configuration is essential to move heat away from the CPU, GPU, VRMs, storage, and power supply components. Given Data / Assumptions: Typical ATX or similar case with front intake and rear/top exhaust fans. CPU cooler and PSU fan rely on controlled airflow paths. System is operating in a standard office or home environment. Concept / Approach: The case is engineered to channel cool air across hot components. Removing covers or slot blanks disrupts pressure and airflow, often creating hot spots. Keeping the cover closed maintains intended ducting and static pressure, improving heatsink and fan effectiveness and dust filtration performance. Step-by-Step Solution: Verify all case fans operate and are oriented correctly (front/bottom intake, rear/top exhaust in most designs).Ensure the side panels and slot covers are installed to preserve directed airflow.Keep dust filters clean to maintain adequate intake volume.Monitor temperatures via BIOS or software to confirm stability under load. Verification / Alternative check: Temperature readings before and after closing the case typically show lower CPU and system temperatures with proper ducting. OEM thermal guidance emphasizes closed-case operation for consistent cooling and acoustics. Why Other Options Are Wrong: Remove the slot cover from the back: Breaks designed airflow channels and can raise temperatures. Remove the CPU fan: Catastrophic—removes primary cooling from the processor. All of the above: Cannot be correct because the other actions are harmful. None of the above: Incorrect because keeping the cover closed is beneficial. Common Pitfalls: Running with side panels off; ignoring dust buildup; poor cable management blocking airflow; reversed fan orientation. Final Answer: Keep the computer cover closed

Question 18

Power-On Self-Test (POST) Memory Count  During the boot process, from which location does the system start counting memory?

Accepted Answer

Introduction / Context: On power-up, a PC performs a Power-On Self-Test (POST) to check essential hardware, including system memory. Knowing where the memory count begins clarifies troubleshooting for RAM-related boot issues. Given Data / Assumptions: Standard PC architecture with DIMMs installed on the motherboard. Optional add-in memory expansion boards are rare in modern systems. Cache memory and video memory are separate from main system RAM. Concept / Approach: The POST initializes the chipset and begins testing main system memory located on the motherboard. Video adapter memory and caches are not counted as part of the base system RAM tally; they are tested separately (if at all) by device-specific routines. Therefore, the memory count starts with the system board RAM. Step-by-Step Solution: Power on the system; BIOS initializes CPU and chipset.POST routine begins scanning and testing base memory on the system board.Additional memory configurations or remapping occur after base checks.Video/expansion devices initialize later in the sequence. Verification / Alternative check: BIOS documentation and diagnostic screens show system memory count reflecting motherboard RAM first, before peripheral initialization. Memory test programs run after POST confirm base RAM locations. Why Other Options Are Wrong: Expansion memory board: Not standard in contemporary PCs; even when present historically, base memory is still on the system board. Video adapter: Its VRAM is separate and not part of the system memory count. Cache: Cache is tested differently and is not tallied as system memory. None of the above: Incorrect because the system board is correct. Common Pitfalls: Confusing VRAM or cache size with main memory; misattributing POST errors to the wrong device. Final Answer: System board

Question 19

Meaning of Parity Errors  In legacy memory systems that implement parity checking, a reported parity error usually indicates faulty memory. True or False?

Accepted Answer

Introduction / Context: Parity is an error-detection scheme once common on SIMMs and early DIMMs. Understanding what a parity error implies is important when diagnosing intermittent crashes, data corruption, or boot failures on older platforms and embedded controllers that still use parity or ECC reporting. Given Data / Assumptions: Parity checking compares stored parity with computed parity on reads. A mismatch indicates a single-bit error was detected. We are discussing classic parity (1 parity bit per byte), not modern ECC multi-bit correction. Concept / Approach: A parity error typically means the data read back from memory does not match the expected parity, strongly suggesting faulty RAM cells, marginal contacts, or signal integrity problems on the memory path. Although the memory module is often at fault, the error can also be caused by a bad slot, dirty contacts, or motherboard issues. Step-by-Step Solution: A parity bit is generated on write and checked on read.If the check fails, the system raises a parity error interrupt or halts.The most common root cause is defective memory or poor seating.Confirm by reseating modules, cleaning contacts, and swapping known-good memory. Verification / Alternative check: Running memory diagnostics or swapping modules across slots can isolate a failing stick. Consistent errors following a particular module or slot confirm hardware fault. Why Other Options Are Wrong: False would minimize the diagnostic value of parity errors. While other causes exist, the usual, most actionable interpretation is bad memory or its immediate interface. Common Pitfalls: Replacing the motherboard before reseating and testing memory; overlooking oxidation on contacts; ignoring power quality that can exacerbate marginal memory behavior. Final Answer: True

Question 20

Troubleshooting an Internal PCI Modem That Will Not Dial  After installing a new internal PCI modem, the system will not dial out. Which issue most likely explains the failure to seize the line?

Accepted Answer

Introduction / Context: Analog dial-up modems have two RJ-11 jacks: LINE (wall) and PHONE (handset). If cabled incorrectly, the modem cannot seize the telephone line to dial, resulting in no dial tone or failed calls. Given Data / Assumptions: Internal PCI modem installed and detected by the OS. Two jacks present: LINE and PHONE. Dial-out attempts fail to produce a call or dial tone. Concept / Approach: The wall telephone line must be connected to the LINE jack so the modem can directly access the PSTN. The PHONE jack is a pass-through for an optional handset and does not supply the modem with an incoming line when used alone. Plugging the wall cable into PHONE prevents line seizure and dialing. Step-by-Step Solution: Inspect cabling at the back of the modem card.Verify the wall RJ-11 cable is plugged into LINE, not PHONE.Retest dialing after correcting the connection.Optionally issue the ATX3 or ATDT commands to confirm dial tone detection and dialing. Verification / Alternative check: After moving the cable to LINE, the modem should detect dial tone and proceed with dialing. Modem logs or terminal sessions will show successful initialization and call progress. Why Other Options Are Wrong: Port speed set too high: Usually auto-negotiated and rarely prevents dialing. Not set up in Control Panel: May affect driver configuration, but mis-cabling is the classic no-dial culprit. LINE-IN wording: If interpreted as the correct LINE jack, that would be proper, not a fault. None of the above: Incorrect because the PHONE jack misconnection is a well-known cause. Common Pitfalls: Confusing the two RJ-11 ports; using faulty phone cords; forgetting to disable call waiting codes that can interrupt dialing. Final Answer: The phone line from the wall is plugged into the PHONE port on the modem card

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