Lesson 3: Troubleshooting PC Hardware

Continuous beep:

Problem with system memory modules or memory controller.

flashing

Upgrade to BIOS or UEFI codebase.

2. Establish a theory of probable cause (question the obvious):

-Conduct research -Question the obvious

BIOS has these roles. BIOS is stored in ROM.

-Power on Self Test (test and initialize the processor, test the video card, disk drives and adapters)) -Hardware configures of your system. -Boot order setup

BIOS security

1, Set passwords 2. Enable secure boot 3. Restrict or disable USB port

Assuming you can rule out an issue with the display, to troubleshoot POST, try the following tests and solutions:

1. Ask what has changed— 2. Check cabling and connections, especially if maintenance work has just been performed on the PC— 3. Check for faulty interfaces and devices— 4. Check the PSU— 5. Check for a faulty CPU or system firmware—

CompTIA's A+ troubleshooting model

1. Identify the problem: 2. Establish a theory of probable cause (question the obvious): 3. Test the theory to determine the cause: 4. Establish a plan of action to resolve the problem and implement the solution: 5. Verify full-system functionality and, if applicable, implement preventive measures. 6. Document the findings, actions, and outcomes.

Hardware Security Module (HSM)

A device that can safely store and manage encryption keys. This can be used in servers, data transmission, protecting log files, etc.

Hardware Security Module from "BIOS"

A secure USB key or thumb drive used to store cryptographic material can be referred to as a hardware security module (HSM). It is also possible to use a removable USB thumb drive to store keys. This is useful if the computer does not support TPM, as a recovery mechanism in case the TPM is damaged, or if a disk needs to be moved to another computer. Secure means that the user must authenticate with a password, personal identification number (PIN), or fingerprint before he or she is able to access the keys stored on the module.

Unified Extensible Firmware Interface (UEFI)

A type of system firmware providing support for 64-bit CPU operation at boot, full GUI and mouse operation at boot, and better boot security.

GPT vs MBR

BIOS use Master Boot Record to hold boot info. UEFI use GPT to hold their information.

1. Identify the problem:

Gather information from the user, identify user changes, and, if applicable, perform backups before making changes. If something worked previously, then experiences mechanical failures, it is likely that the problem has arisen because of some user-initiated change or some environmental or infrastructure change.

Hardware ROT

Hardware Root of Trust, a cryptographic module in a computer system that can endorse trusted execution and attest to boot settings and metrics. Uses to scan and verify OS files before boot. Also known as a TPM

smart

In addition to symptoms that you can detect by observing system operation, most fixed disks have a self-diagnostic program called Self-Monitoring, Analysis, and Reporting Technology (SMART) . SMART can alert the operating system if a failure is detected.

3 long beeps

Keyboard issue (check that a key is not depressed).

blue screen of death (BSOD)

Microsoft status screen that indicates an error from which the system cannot recover (also called a stop error). Blue screens are usually caused by bad driver software or hardware faults (memory or disk). Other operating systems use similar crash indicators, such as Apple's pinwheel and Linux's kernel panic message.

1 long, 1 short beep:

Motherboard problem.

1 short beep:

Normal POST- system is OK. Most modern PCs are configured to boot silently, however.

2 short beeps:

POST error- error code shown on screen.

Repeating short beeps:

Power supply fault or motherboard problem.

No beep:

Power supply, motherboard problem, or faulty onboard speaker.

There are typically three generic approaches to resolving an IT problem:

Repair—You need to determine whether the cost of repair makes this the best option. Replace—Often more expensive and may be time-consuming if a part is not available. There may also be an opportunity to upgrade the part or software. Workaround—Not all problems are critical. If neither repair nor replacement is cost-effective, it may be best either to find a workaround or just to document the issue and move on

power-on self-test (POST) .

The POST is a diagnostic program implemented in the system firmware that checks the hardware to ensure the components required to boot the PC are present and functioning correctly.

"boot options" from BIOS

This defines the order in which the system firmware searches devices for a boot manager. Disk or network adapter device from which an operating system can be loaded.

1 long, 2 or 3 short beeps:

Video adapter error.

There are two main scenarios for RAID failure:

failure of a device within the array and failure of the whole array or volume.

Trusted platform module (TPM) from "BIOS"

is a specification for hardware-based storage of digital certificates, cryptographic keys, and hashed passwords. The TPM establishes a root of trust. Each TPM microprocessor is hard coded with a unique, unchangeable key, referred to as the endorsement key. During the boot process, the TPM compares hashes of key system state data (system firmware, boot loader, and OS kernel) to ensure they have not been tampered with. The TPM chip has a secure storage area that a disk encryption program such as Windows BitLocker can write its keys to.

Firmware is

specialized program code stored in flash memory. Firmware is distinct from software because it is very closely tied to the basic functions of a specific hardware device type and model. PC or system firmware provides low-level code to allow PC components installed on a particular motherboard to be initialized so that they can load the main operating system software.

A fixed disk that is failing might display the following symptoms:

§ Unusual noise (HDD only)—A healthy hard disk makes a certain low-level noise when accessing the platters. A loud or grinding noise, or any sort of clicking sound , is a sign of a mechanical problem. § No LED status indicator activity— § Constant LED activity—. § Bootable device not found— § Missing drives in OS— § Read/write failure— § Blue screen of death (BSOD)—