Lesson 3: Objectives Flashcards
What are the 3 parts of troubleshooting a problem?
Cause
Symptom
Consequence
From a buisness perspective, what is the most important part of the problem to solve, the cause, the symptom or the consequence?
Consequence
Step 1 in CompTIA’s troubleshooting model is what?
Identify the problem
Step 2 in in CompTIA’s troubleshooting model is what?
Establish a theory of probable cause (Question the obvious)
Step 3 in CompTIA’s troubleshooting model is what?
Test the theory to determine the cause
Step 4 in CompTIA’s troubleshooting model is what?
Establish a plan of action to resolve the problem and implement the solution
Step 5 in CompTIA’s troubleshooting model is what?
Verify full system functionality and, if applicable, implement preventitive measures
Step 6 in CompTIA’s troubleshooting model is what?
Document the findings, actions, and outcomes.
According to CompTIA’s troubleshooting model, during which step should you perform backups?
Step 1: Identify the problem
According to CompTIA’s troubleshooting model, during which step should you conduct external or internal research based on symptoms, if necessary?
Step 2: Establish a theory of probable cause (Question the obvious)
According to CompTIA’s troubleshooting model, what should you do if you test a theory and determine the theory is not confirmed? (Step 3)
Re-establish a new theory of escalate the problem.
According to CompTIA’s troubleshooting model, what should you do while establishing a plan of action to resolve the problem and implement a solution? (Step 4)
Refer to the vendor’s instructions for guidance.
Identifying the problem means establishing what?
The consequence or impact of an issue and listing symptoms.
What should be used to prioritize each support case within the overall process of problem management?
The consequence.
Where will you find one of your best sources of information once a problem arises?
From the first report of the problem, generally a user or another technician if you can ask the right questions.
What are some good questions to ask when gathering information from the user? (6)
-What are the exact error messages appearing on the screen or coming through the speaker?
-Is anyone else experiencing the same problem?
-How long has the problem been occurring?
-What changes have been made recently to the system? Were these changes initiated by you or via another support request?
-If something worked previously, then experiences mechanical failures, it’s likely the problm has arisen because of some user-initiated change or some environmental or infrasture change
-Has anything been tried to solve the problem?
What is the Severity of the problem?
How many are affected
How do you determine the probable cause of a problem?
By identifying the symptoms and considering possible causes to determine what the probable cause is.
When researching a problem, be aware of what? (2)
-Internal documentation and information and
-External support resources such as vendor support or forums
What steps should you take when researching a problem? (5)
-Physical inspection—look and listen
-If symptoms / problem is no longer apparent, attempt to reproduce the problem, repeat the exact circumstances that cause the failure or error.
-Check system documentation, installation, and event logs and diagnostic tools for useful information
-Consult other technicians who might have worked on the system recently or might be working on some related issue. consider environmental and infrastructure changes might have been instigated by a different group within the company.
-Consult vendor documentation and use web searches and forum resources to see if the issue is well-known and has an existing fix
Name 3 generic escalation routes:
-Senior technical and admin staff, SME’s (Subject Matter Experts), and developers/ programmers within your company
-Suppliers and manufacturers via warranty and support contracts and helplines or web contact portals
-Other support contractors / consultants, websites, and social media
What are the 3 generic approaches to resolving an IT problem?
Repair
Replace
Workaround
What is the main factor of consideration when repairing a problem?
Cost of repair
What is the main factor when replacing an IT problem?
Often more expensive and can be time-consuming if a part isn’t available. Upgrades may be possible though
When might you use a workaround to solve an IT problem?
When a problem isn’t critical and neither repair nor replacement is cost-effective. It may be best to just document the issue and move on.
To replace a system or part undar warranty what do you need from the vendor?
A RMA Returned Materials Authorization ticket
When devising a plan of action, what considerations should be made?
(4)
Resources
Time
Cost
Impacts
What will an effective configuration management system help with?
Understanding how different systems are interconnected
When implementing a solution, when should you test?
After each change
When implementing a solution and testing after each change, what should you do if the change doesn’t fix the problem?
Reverse the change and try something else.
Name 5 examples of tests to ensure the system as a whole is functioning.
-Trying to use a componenet or performing the activity that prompted the problem report
-Inspecting a component to see whether it is properly connected or damaed or whether any status or indicator lights show a problem
-Disabling or uninstalling the component if it might be the cause of a wider problem
-Consulting logs and software tools to confirm a component is configured properly
-Updating software or a device driver
What are the three main areas of documentation for IT problems?
Findings
Actions
Outcomes
According to CompTIA’s troubleshooting model, what two steps should you take to identify the problem (Step 1)
-Gather information from the user, identify user changes, and, if applicable, perform backups before making changes.
-Inquire regarding environmental or infrastructure changes
For many years, the system firmware for a PC was a type called the BIOS or Basic Input / Output System. Newer models use a different kind of firmware called what?
UEFI Unified Extensible Firmware Interface
UEFI Unified Extensible Firmware interface provides support for what? (6)
A 64-bit CPU operation at boot
A full GUI Graphical User Interface
Mouse operation at boot
Network functionality at boot
Better boot security.
May also support a legacy BIOS mode
The key combinations to reach the UEFI Unified Extensible Firmware Interface vary from system to system but typical examples include (6)
Esc
Del
F1
F2
F10
F12
If a computer boots too quickly to press the key combination to reach the UEFI Unified Extensible Firmware Interface screen, how can you access it?
Shift-click the restart button from the windows logon screen to access UEFI boot options
What are the typical choices for boot device order? (4)
Fixed Disk HDD or SDD
Optical Drive
USB
Network / PXE
Fixed Disk (HDD or SDD) boot devide order: How should SATA boot disk be connected?
-Sata boot disk should generally be connected to the lowest numbered port but its usually possible to select the hard drive sequence if multiple fixed drives are installed.
-An SSD attached with SATA will be listed with SATA/AHCI devices
-AN SSD installed as a PCIe AIC Add-in Card or the M.2 interface will be listed under NVMe.
When would you need to make the Optical Drive the highest boot priority?
If you’re performing a repair install from optical media
When would you set Network / PXE as the highest boot priority?
When you’re using the network adapter to obstain boot settings from a specially configured server.
Why is allowing USB setup a security risk?
Because a setup program might alow individual ports to be enabled or disabled.
Where would cooling fans be controlled?
System settings typically under a menu such as cooling, power, or advanced.
What sort of fan options are available in the system settings? 5
Balanced
Cool (Runs fans harder)
Quiet (Reduce fan speed and allow higher temperatures)
Fanless
Custom
What are Duty Cycle Settings used for?
To control the frequency of power pulses to keep the. Fan running. A high % makes the fan run faster
What two types of boot passwords might be used?
-Supervisor / Admin / Setup: Protect access to the system setup program
-User / System: Lock access to the whole computer. Very secure way of protecting the entire PC as nothing can be done until the firmware as initialized the system.
Under a secure boot, how is the firmware configured?
With cryptographic keys that can identify trusted code. The system firmware checks the OS boot loader using the stored keys to ensure that it’s been digitally signed by the OS vendor. This prevents a boot loader that’s been modified by malware or an OS installed without authorization from being used
TPM (Trusted Platform Module) establishes what?
Root of trust
Each TPM (Trusted Platform Module) microprocessor is hard-coded with what?
Trusted Platform Module
A unique, unchangeable key, referred to as the endoresement key.
TPM has a secure storage area used for what?
Disk encryption programs such as BitLocker can write their keys to.
TPM can be enabled, disabled, and reset where?
Trusted Platform Module
System setup program, though it’s possible to
During the boot process, the TPM compares what?
Trusted Platform Module
The hashes of the key system state data (System firmware, boot loader, and OS kernel) to ensure they haven’t been tampered with.
Is hardware or software based cryptographic key storage more prone to tampering and insider threats?
Software is more susceptible
When might you want to use a removable USB thumb drive (AKA a HSM) to store keys?
-If a computer doesn’t support TPM
-As a recovery mechanism in case the TPM is damaged
-If a disk needs to be moved to another computer.
A computer that won’t start and a PC that suddenly turns off or restarts has what as a common cause?
Power problems
What kind of voltage is used to power motherboard components and peripheral devices?
VDC DC voltages
What voltage of power does a PSU supply immediately and what computer components start up as a result?
12 V power is supplied immediately and fans and hard disks should spin up.
Once the fans and hard disk have been supplied power, the PSU tests what power supplies and that power is sent where?
5 V and 3.3 V supplies are tested and power is sent to the processor
How would you diagnose no power symptoms?
Check if the LED’s on the front panel of the system case are lit up and whether you can hear the fans.
Name 4 causes of a power issue
-A fault in the PSU
-Incoming electricity supple
-Power cables / connectors
-Fuses
To isolate the cause of no power, what tests should you try? (6)
- Check that other equipment in the area is working—there may be a fault in the power circuit or a complete power failure
- Try plugging another piece of known-good basic electrical equipment into the wall socket.
- Check that the PSU cabling is connected to the PC and on the wall socket correctly and that all switches are on
- Try another power cable—there may be a problem with the plug or fuse. Check that all wires are connected to the orrect terminals in the plug.check the fuse resistance with a multimeter or swap for a known good fuse.
- Try disconnecting extra devices, such as plug-in graphics card. If this solves the problem, either the PSU is underpowered and you need to fit one with a higher wattage rating or one of the devices is faulty
- If you can ensure a safe working environment, test the PSU using a multimeter or power supply tester
What should you do if you suspect that a power supply is faulty?
Do not leave it turned on for longer than necessary and do not leave it unattended. Turn off immediately if there are any unusual sights, smells, or noises
A Black Screen—power present but the computer doesn’t start and there are no beeps from the internal speaker, what kind of a failure are you likely experiencing?
Either the display is faulty or the POST procedure isn’t executing.
What steps should you take to troubleshoot POST? (5)
- Ask what changed—such as firmware updated and pc hasn’t been booted since, reset procedure
- Check cabling and connections, especially if maintenance work has just been performed on the PC—incorrectly oriented storage adapter cable or badly seated adapter card can stop POST from running.
- Check for faulty interfaces and devices—faulty adapter card or device can hault POST.
- Check the PSU—even though fans are receiving power, there may be a fault that’s preventing the power good signal from being sent to the CPU, preventing POST
- Check for a faulty CPU or system firmware—if possible, replace CPU chip with known good one or update the system firmware.
What resource might you use to find the meaning of a POST beep code?
The manufact’s website.
Original IBM PC Beep Code: 1 short beep:
Normal POST, modern machines are configured to boot silently
Original IBM PC Beep Code: 2 short beeps
POST error, error code shown on screen
Original IBM PC Beep Code: No Beep
Power Supply, motherboard problem, or faulty onboard speaker
Original IBM PC Beep Code: Continuous Beep
Problem with system memory modules or memory controller
Original IBM PC Beep Code: Repeating short beeps
Power supply fault or motherboard problem
Original IBM PC Beep Code: 1 long, 1 short beep
Motherboard problem
Original IBM PC Beep Code: 1 long, 2 or 3 short beeps
Video adapter error
Original IBM PC Beep Code: 3 long beeps
Keyboard issue (Check that a key isn’t depressed)
If the first device listed in the boot sequence isn’t available what will the computer do?
Attempts to boot from the next listed device
How is (hard) drive activity usually indicated?
An LED on the front panel
If a fixed disk is not detected at boot what should you try?
Check to make sure the disk is powering up. Drive activity is indicated by LED on the front panel.
If it’s inactive, ensure the drive has a power connector attached. If no LED’s or you don’t hear the HD spinning,..
What are the two ways of formatting the boot information?
MBR and GPT
Where is the boot sector located?
Either on the sector after the MBR or the first sector of each partition
Between the MBR and GPT, which is restricted to a single sector?
MBR
Damage to either the MBR or GPT causes what kind of errors? (3)
-Boot Device not found
-OS not found
-Invalid Drive specification
After the boot device is located and the the code from the boot sector is loaded into memory and takes over from system firmware, the boot sector code loads the rest of the OS files into system memory. Error messages after this point can usually be attributed to what?
Software or device driver problems
BSOD is also called what?
Stop Error
BSOD are usually caused by what? 3
Bad driver software
hardware faults (memory or disk)
corruption of OS files.
Where can you find more information on BSOD?
-QR code on the BSOD
-Error should be written to the System log with BugCheck as the source
What are the apple and linux equivalents to the BSOD?
-Apple—Pinwheel
-Linux—Kernal Panic Message
From the event description on a Windows BSOD, besides the QR code, what would you use to find information about the event online?
The first hex value such as 0x0a
When is a HDD most likely to fail?
Either in the first few months of operation or after a few years. (Due to mechanical problems)
With any fixed disk (HDD or SSD), a sudden loss of power can cause what?
Damage and / or file corruption, especially if the loss of power occurs during the middle of a write operation.
What are the symptoms of a fixed disk that is failing? (7)
-Unusual noise (HDD)—Clicking sound or grinding noise
-No LED status Indicator Activity
-Constant LED Activity—AKA disk thrashing
-Bootable Device Not Found
-Missing Drives in the OS
-Read / Write Failure
-BSOD
When you hear a grinding noise or a clicking sound on a HDD, what kind of problem does it indicate?
Mechanical Problem
Fixed Disk: No LED status indicator indicates what?
The whole system might not be receiving power or the individual disk unit could be faulty
Fixed Disk: Constant LED Activity indicates what? (3)
-Can be a sign there isn’t enough system RAM so the disk is being used continually for paging.
-Could also be a sign of a faulty software process or
-The system is infected with malware
Fixed Disk: Bootable Device not Found cause
The disk is faulty or there is file corruption
Fixed Disk: Missing drives in OS could indicate what? If system boots but a second fixed disk or removable drive doesn’t appear in tools such as file explorer or cannot be accessed via command line,
Check that it’s been initialized and formatted with a partition structure and file system
Fixed Disk: Missing drives in OS could indicate what if the disk isn’t detected by a config tool such as Windows Dsk Management
Hardware or cable / connector fault
Fixed Disk: Read / Write Failure results in what kind of error when trying to open or save a file?
Cannot read from the source disk.
Fixed Disk: Read / Write Failure: Cannot read from the source disk on an HDD is usually caused by what?
Bad sectors
Fixed Disk: Read / Write Failure: what are bad sectors on an HDD caused by?
2
-Power failure
-Mechanical fault
Fixed Disk: Read / Write Failure: what tests should you do?
Chkdsk, if more bad sectors are located each time it’s run the disk is about to ail.
Fixed Disk: Read / Write Failure: On a SSD, errors will be caused by what?
One or more bad blocks. SSD circuitry degrades over the course of many write operations.
Extended read / write times is a symptom of what?
Failing drive.
What should you do if you’re alerted to a drive failure by SMART or experience symptoms of drive failure such as extended read / write times?
Run more advanced diagnostic tests on the drive.
Where can you get utilities for testing drives?
Most fixed disk vendors supply utilitites for testing drives
Where would you find IOPS?
Windows utilities where you use SMART and nu manual tests
What kind of IOPS (Input / Output Operations per Second) results might indicate the device itself is faulty?
If performance of the disk is reduced from the vendors baseline measurements under test conditions
IOPS (Input / Output Operations per Second): what does it mean if the test results are slower to the devices benchmark under test conditions?
Any slow read / write access observed is likely to be due to a more complex system performance issue.
IOPS (Input / Output Operations per Second): What could cause the complex system performance issues (When the IOPS test meets baseline measurements)
(4)
-Application load
-General system resource issues
-File fragmentation (On hard disks)
-Limited remaining capacity
Why might you experience extended read / write times?
Particular sectors (HDD) or blocks (SSD) fail.
When bad sectors or blocks are detected on HDD or SSD, what happens?
The disk firmware marks them as unavailable for use.
If there is file corruption on a hard disk and no backup, how can you attempt to recover data from the device?
Using a recovery utility
How is file recovery from a SSD usually done?
Only with highly specialized tools.
What are the two main RAID failure scenarios?
-Failure of a device within the array
-Failure of the whole array or volume
If one of the underlying RAID devices fails, the volume will be listed as what?
Degraded
Most desktop-level RAID solutions can handle the loss of how many disks?
1
After swapping out a bad RAID array, how would you rebuild the RAID? (2)
-Using the RAID Configuration utili if using hardware RAID controller
-Using an OS utility if using RAID software.
When hot-swapping a faulty disk from a RAID array, what mistake could cause the array to fail?
Accidentally swapping out a healthy disk instead of the failing one
How is disk failure normally indicated on a RAID array?
With a red LED
If a volume in a RAID array isn’t available what went wrong?
-More than the tolerated number of disks has failed or
-The controller has failed
If the boot volume of a RAID is affected what will happen?
The OS won’t start
If too many of a RAID disks have failed, what should you do?
-Turn to the latest backup or
-Try to use file recovery solutions.
If the issue with a RAID is controller failure, what should you do with the data and how should you fix it?
-The data on the volume should be recoverable, though there may be fie corruption if a write operation was interrupted by the failure.
-Install a new controller or import the disks to another system.
If the RAID failure affects the boot process,
Use the RAID Configuration utility to verify its status.
If you cannot access the RAID configuration Utility, then what?
The controller itself is likely to have failed.
Symptoms such as:
-System locking up
-Intermittent shutdowns
-Continuous rebooting
-BSOD/Kernel Panic Errors
-Application Crashes
Are difficult to diagnose with a specific cause, especially if you don’t witness them directly. Most likely causes are what?
-Software
-Disk / File Corruption Problems
-Malware
Symptoms such as:
-System locking up
-Intermittent shutdowns
-Continuous rebooting
-BSOD/Kernel Panic Errors
-Application Crashes
If not attributed to Software / Malware / Disk or File Corruption:
(3)
-If they occur when the PC has been running for a long itme, could be a thermal problem
-Check Power supply is providing good, stable voltages to the system.
-If not the power supply, must suspect a problem with memory, CPU or motherboard.
Vendor supplied diagnostic test programs to identify hardware-level errors are often run from where?
The firmware setup utility instead of the OS
Burning smell or smoke almost always indicates what?
Something, usually the PSU is overheating.
What should you do if you smell something burning from a PC
Shut it off immediately and investigate the problem.
Besides the PSU overheating, what else can cause a burning smell?
Case and / or fan vents are clogged with dust.
Techniques for diagnosing and correcting overheating issues includes:
(5)
-Internal Temperature Sensors
-CPU Fans are Working
-Ensure Heat Sink is properly fitted
-Use blanking plates to cover holes in the back
-Verify the room temperature the PC is installed in
Where and how would you check the system internal temperature sensors?
Driver or management software and use vendor documentation to confirm the system is operating within acceptable limits
What will happen if the processor is running too hot?
It can decrease performance. It can cause crashes or reboot the machine
How can installing an upgraded processor cause overheating problems?
The factory fan might not be enough to properly cool it down.
Actual physical damage to a computer is usually caused where?
-Peripherals
-Ports
-Cables
What might indicate a component has “Blown”
-It may have scorch marks.
-Capacitor swelling
What might indicate capacitor swelling?
If capacitors are swollen or bulging or emitting any kind of reside, they could have been damaged or failed due to manufacturing defect
If there’s physical damage to the motherboard, how will you confirm whether there’s a problem?
With diagnostic software to run tests.
Name 3 common causes for performance issues:
-Overheating
-Misconfigurations
-Check for problems with Computing, storage and networking functions
What might be negatively impacted by inaccurate date/time?
-Security systems such as authentication and
-Utilities such as backup programs and
-Schedulers
How is the RTC (Real Time Clock) chipset powered?
By battery when the computer is powered off and the computer when it’s powered off.
What kind of battery does the RTC use?
a coin cell lithium battery
If the date / time displayed on the system firmware setup program is inaccurate, it might be a sigh of what?
That the RTC battery is failing.
RTC battery is also often called what?
CMOS battery
Common causes of missing video include:
-Monitor turned off / not plugged in / standby
-Inaccurate data source (pulling video from the proper place)
-Cabling and connectors
What should you check cabling and connecting for when assessing missing video issues
-Securely connected at both ends
-Not stretched or crimped
-Proper cabling for application (ie HDMI for HDMI / 4k capable for 4k)
How should you troubleshoot cabling issues?
Using the known good technique.
What kind of imaging technologies can projectors use? (3)
-CRT
-LCD
-DLP
What kind of bulbs does a PC monitor use?
-Backlight
-LED array
What might indicate a projector bulb needs to be replaced (4)
-Image may start to dim
-Bulb health warning indicator light
-Failed bulb / burned out bulb
-Might hear a pop from within the broken filament
What typically causes intermittent projector shutdown issues?
Overheating
What should you attempt to fix intermittent projector shutdown issues?
-Check the projectors fan is working
-Vents are free from dust and are unobstructed
-Ambient temperature isn’t too high.
If you rule out overheating as the cause for intermittent projector shutdown issues, what should you check?
Loose connector cables and verify the bulb is secured properly
What are the common causes of video quality issues>
Fault in the display itself or with the input source (Signal from video card)
What are the common problems associated with video quality? Symptoms. (7)
-Dim image
-Fuzzy image
-Flashing screen
-Dead pixels
-Burn-in
-Incorrect color display
-Audio issues
Video Quality Problems: Dim Image: check for
-Use OSD to check brightness / contrast
-Check for Power-saving mode, auto-brightness, adaptive brightness, eye-saving features
Video Quality Problems: Dim Image with almost invisible image usually means what and what’s the solution?
-The display’s backlight probably failed
-Unit will need to be repaired under warranty or replaced
Video Quality Problems: Fuzzy Image: Cause
-If the output resolution doesn’t match the display devices native resolution which can be caused by:
-Faulty or incorrectly configured video card driver
Video Quality Problems: Fuzzy Image: How would you resolve?
-Use OS to change the output resolution
-Update the driver
Video Quality Problems: Flashing Screen Causes?
-Video Cable and Connectors
-Displays backlight / circuitry starting to fail
-Faulty or overheating video card (attach to new computer to isolate this cause)
Video Quality Problems: Symptoms of a Failing Display
-Flashing screen
-Bright or dim bands or lines
-Bright spots at the edge of the screen
Video Quality Problems: Dead Pixels: What causes dead pixels?
Defects in a flat-panel monitor
Video Quality Problems: Dead Pixels: if a digital display panel has stuck (Constantly bright) pixels, how might fix it?
-There are software utilities available to cycle the pixel through a series of relatively extreme color states to try to reactivate it.
-Sometimes you can fix it by gently pressing or tapping the affected area of the screen with a stylus or pencil eraser
Video Quality Problems: Dead Pixels: What is the risk of tapping the screen to attempt to fix the pixels?
You can cause further damage or scratch the screen
Video Quality Problems: Dead Pixels: How would you fix dead pixels (Solid black)
They usually cannot be fixed.
Video Quality Problems: Burn-In: What causes burn-in?
When a static image is displayed for an extended period of itme, the monitor’s picture elements can be damaged and a ghost image is burned into the display permanently.
What kind of displays are more prone to burn-in issues?
Plasma screens and OLED
Video Quality Problems: Incorrect Color Display: How should color settings be configured? What should be used?
With the assistance of a color profile
Video Quality Problems: Incorrect Color Display: Where might you find the settings to adjust the color display?
Color management applet in control panel
Video Quality Problems: Incorrect Color Display: color glitches such as purple or green horizontal lines. What are they usually caused by? And how would you fix it?
-Faulty or loose connector or cabling that’s either faulty or of insufficient wuality for the current image resolution.
-Replace the cable, if this doesn’t fix it then
-There could be a hardware fault in the monitor or graphics adapter
Video Quality Problems: Audio Issues: What kinds of connections cannot deliver combined video and audio signal?
-DVI
-VGA
Video Quality Problems: Audio Issues: If there’s no sound from built-in r separate speakers, check power, cables / connectors, and any physical volume control. If you discount these issues, what should you do?
-Use the OS to verify the audio output is set to the correct device and
-Check the OS volume control
According to CompTIA’s troubleshooting model, during which step should you begin documentation?
-Step 1: Identify the problem while gathering information from the user.
