Lesson 3: Troubleshooting PC Hardware

CompTIA A+ Troubleshooting Model

CompTIA A+ Troubleshooting Model

1. Identify the problem

2. Establish a theory (question the obv)

3. Test the theory

4. Establish an action plan

5. Verify full system functionality

6. Document findings

Basic Input/Output System (BIOS)

Legacy system firmware on a motherboard

• Boots computer & initializes hardware

• Manages data flow between OS & devices

• Only supports 32-bit operation

Firmware

Software programmed into a hardware device on flash memory, providing low-level control and functionality. It is essential for the device to operate properly.

Unified Extensible Firmware Interface (UEFI)

Modern firmware interface replacing BIOS

• Supports larger hard drives and faster boot times

• Support for 64-bit CPU

• May also support booting in a legacy BIOS mode

Boot Options Sequence

The order in which a computer searches for and loads the operating system, typically from devices like hard drives, USB drives, or network servers.

Also called Boot Device Priority

USB Permissions

Settings that determine which users or applications can read from or write to a USB device connected to a computer.

Boot Password

A security feature that restricts unauthorized access to a computer by requiring a password to be entered before the OS can start up.

Secure Boot UEFI

A security feature that ensures only trusted software is loaded during the boot process, protecting against malware and unauthorized software.

Trusted Platform Module (TPM)

A hardware-based security chip that securely stores sensitive information, such as encryption keys and passwords, to enhance system security.

Endorsement Key

A unique RSA key embedded in a Trusted Platform Module (TPM) to securely sign data and attest to the integrity of the platform.

Hardware Security Module

Device that safeguards and manages digital keys, encryption, and decryption for secure authentication and data protection.

Power-On Self-Test (POST)

A diagnostic testing sequence run by a computer when it is turned on to ensure hardware components are functioning correctly.

Beep Code

A series of audible beeps produced by a computer during the boot process to indicate hardware issues or errors.

1 Short beep

Normal POST - system is okay (can also be silent)

2 Short beeps

POST Error - error code shown on screen

No beep

PSU, motherboard problem, or faulty speaker

Continuous beep

Problem with system memory modules or memory controller

Repeating Short beeps

PSU fault or motherboard problem

1 long, 1 short beep

Motherboard problem

1 long, 2 or 3 short beeps

Video adapter error

3 long beeps

Keyboard issue (check that a key is not depressed)

Master Boot Record (MBR)

The first sector of a computer's hard drive that contains the partition table and bootloader code for booting the operating system.

Legacy format with a 2.2 TB limit on partition sizes

Modern Globally Unique ID (GUID) partition table (GPT)

Modern partition table system used in computers, supports large disk sizes and up to 128 partitions, replacing the older MBR system. No limit

Blue Screen of Death (BSOD)

A Windows operating system error screen that appears when a system encounters a critical error, causing it to crash and display a blue screen with error codes.

HDD Failure

The malfunction of a hard disk drive resulting in data loss and potential hardware damage. Common causes include physical damage, overheating, and wear over time.

SDD Failure

Solid State Drive malfunction, leading to data loss or system crashes. Regular backups can help prevent data loss in case of SDD Failure.

• Usually more reliable

• Has a max expected lifetime

Unusual noise (HDD only)

Grinding or clicking sound, indicative of HDD failure

No LED Status Indicator

Indicates an issue with the whole system or an individual disk

Constant LED Activity

Disk thrashing; could be not enough RAM or too much paging. May also indicate:

• Malware

• Faulty software

Paging

A memory management scheme that allows the operating system to store and retrieve data from secondary storage to free up space in RAM.

Disk Thrashing

Excessive swapping of data between RAM and virtual memory, leading to a decrease in performance due to constant read/write operations on the hard disk.

Bootable device not found

Faulty disk or file corruption

Missing drives in OS

When a drive is not detected by the operating system due to connection issues, driver problems, or hardware faults.

Read/Write Failure

A situation where a system is unable to read from or write to a storage device, resulting in data loss or corruption.

Self-Monitoring, Analysis, and Reporting Technology (SMART)

A self-diagnostic program that monitors the health of storage drives to predict potential failures.

• Alerts the OS of failure

• Can be run if it is suspected that a drive is failing or there are extensive read/write times.

Troubleshoot RAID Failure

Process of identifying and resolving issues with a RAID system to restore data redundancy and functionality.

• Usually RAID is what protects against failure

• If degraded, backup data and replace the failed device(s)

Overheating

When an object or system becomes excessively hot, often leading to damage or malfunction.

• Shortens lifespan

Swelling of Capacitors

Expansion of capacitor casing due to internal pressure build-up, often caused by overheating or age, leading to component failure.

• Swollen batteries are informally called spicy pillows

RTC Coin Cell

Small battery on the motherboard that powers the Real-Time Clock (RTC) and BIOS settings when the computer is turned off.

• Should be synced with other computers on the network

• Replace if not synced

Troubleshoot Dim Image

Use OSD to check brightness and contrast. Make sure power-saving, adaptive brightness, and eye comfort are turned off.

Troubleshoot Fuzzy Image

• Output resolution doesn’t match the display resolution.

• Use the OS to change the output resolution or update the driver.

Troubleshoot Flashing Screen

Check cables and connectors

Troubleshoot Dead Pixels

If pixels are black, must replace device

Troubleshoot Burn in

• Mainly Plasma and OLED

• Ghost image burned on screen, must be replaced

Troubleshoot Incorrect Color Display

• May need to be calibrated

• Check cables, if neither of these fix the issue, then there may be a fault in either the monitor or graphics adapter

Troubleshoot Audio Issues

• HDMI, DisplayPort, and other cables should be checked

• Use the OS to verify the audio output is through the desire medium (ex: output is speakers and not headphones or something else)