Transcript Diagnostics - WordPress.com

RUN STANDARD
DIAGNOSTIC
TESTS
What is a Diagnostic Test?

A diagnostic test is the procedure of examining the
state of a computer system hardware or software to
locate faults.
Built-in Diagnostic tools


Each computer system has built-in tools to determine
the operating state of the machine.
The most common computer problems will be found
during these 3 phases:
1.
2.
3.
booting the computer
loading the operating system
manually checking the system.
Booting The Computer

Booting involves:
1.
2.
3.


Turning the machine on
Making sure the power LED is on
Seeing that the screen reflects the expected activity
Involved In this process is the POST or Power On
Self Test diagnostic tool.
Any fault related to a major component will be
detected by POST.
Power On Self Test (POST)

POST tests every major component that is critical to
the computers operation.
Power On Self Test (POST)

Any faults found during POST will result in either:
1.
2.


An error message on the screen
A series of beeps called beep codes which are
unique to the BIOS manufacture.
To view detailed information that POST has
gathered you must go into the BIOS.
For a Mac system, when you boot the PC will either
show a happy face and load, or show a sad face
and refuse to load.
Power On Self Test (POST)
American Megatrends Inc. (AMI) beep codes:
Beep Code
Meaning
1 beep
There is a problem in the system memory or the motherboard.
2 beeps
Memory parity error. The parity circuit is not working properly.
5 beeps
The system CPU has failed.
6 beeps
Keyboard controller failure.
8 beeps
Video memory error. The BIOS cannot write to the frame buffer memory
on the video card.
9 beeps
ROM checksum error. The BIOS ROM chip on the motherboard is likely
faulty.
10 beeps
CMOS checksum error. Something on the motherboard is causing an error
when trying to interact with the CMOS.
Continuous beeping
A problem with the memory or video.
Power On Self Test (POST)
Phoenix beep codes:
Beep Code
Meaning
1-1-1-3
Faulty CPU/motherboard.
1-1-2-1
Faulty CPU/motherboard.
1-1-4-1
Level 2 cache error.
1-1-4-1
Level 2 cache error.
1-2-2-3
BIOS ROM error.
1-3-3-1
2-3-1-1
2-3-3-3
2-1-4-3
2-2-1-1
3-1-4-1
3-2-1-1
3-2-1-2
Extended memory error.
Video card failure.
Floppy drive or hard drive failure.
Loading the Operating System


Most common faults at this stage are due to failures
or mis-configuration in minor hardware as well as
system services failing to load.
All this activity Is logged and can be viewed at any
time.
Booting the Operating System

If the faults in the OS boot process are so sever that
the OS won’t boot most systems offer a restricted or
“Safe Mode” as well as recovery tools.
Manually Checking the System

Most OS come with built-in managements tools that
can be used to view information or manage
hardware devices.
Manually Checking the System

Some common diagnostic tools offered by Microsoft
Windows OS are:
 Device
Manager
 Event Viewer
 Check Disk (chkdsk)
 Windows Services
 Memory Diagnostic
 Performance Monitor
 Task Manager
 Disk Defrag
Common Problem Scenario

System appears dead
 Listen
to the power supply and determine if the internal
fan starts up. If the fan does not start up then the cause
of the problem could be:
1. The system is not plugged into a power outlet, or the
outlet has no power.
2. The power supply unit is faulty.
3. There is an internal short circuit and the fan does not
start as a protective measure.
4. The computer is dead!
Common Problem Scenario

No Video
 No
video appears on the screen when the system is
performing its POST. Things to consider:
1. Video card is faulty — swap it out with a known
good card.
2. There is a fault in the motherboard.
3. The video card is not inserted correctly.
4. The monitor is turned off or has no power.
Common Problem Scenario

No boot device or unable to boot.
 The
system could not find a bootable device; the most
likely cause is the hard disk drive. Things to consider:
1. Missing boot files — they may have been deleted by
the user.
2. A virus has caused damage to the boot files or has
corrupted the file system or Master Boot Record
(MBR).
3. A common mistake is a floppy disk being left in the
drive.
4. Cables not connected to hard disk drive properly.
Common Problem Scenario

System hangs / locks up
 One of the most difficult problems with personal computers
occurs when it appears as though a system is not responding
to any user input. Possibilities are:
1.
Faulty memory (RAM) — you could turn memory testing on
in CMOS settings which may confirm the problem, or
perform a rigorous test using third-party diagnostic
software.
2.
Conflict with devices — you should check the systems
properties information available on you operating system
platform, for any messages or indications of conflict.
3.
Device driver is faulty — try to isolate the problem
occurrence to when a particular device is in use, such as a
scanner or printer. A driver update may be a solution.
Common Problem Scenario

The Operating System has become unstable.
 The
most reliable solution is to reinstall the operating
system. Alternatively you may be able to restore to a
backup of the system, where performance levels were
known to be good.
Fault Finding Procedures
Communicate


Experienced technicians can ask a few pointed
questions to isolate the cause of a problem.
A history can be established e.g. What worked
before, What has changed, What works now.
Fault Finding Procedures
KISS Principle
Keep It Simple Stupid, Look for the simple things first.
 If a system doesn’t start check if the power is on.
 If nothing displays on a monitor try another one.
 If you suspect a video card fault swap it with a known
good one.
 If the mouse-pointer movement seems erratic, then turn
the mouse over and clean the rollers, if it still is not
working properly then replace it with a new mouse.
Fault Finding Procedures


POST Card / Diagnostic Card
Where a system does not boot, or appears to be
dead, there are some specialist interface cards that
can be used to diagnose the problem.
A set of LEDs display a code that can be
referenced from the manual.
Preventative Maintenance

The best way to avoid many of the issues discussed
is to undertake preventative maintenance.
Preventative Maintenance

When we undertake maintenance we aim to:
 preserve
our IT systems in optimal condition
 fix problems that occur
 upgrade the existing systems to minimise future risks to
the business.
Preventative Maintenance


The idea of preventative maintenance to prevent a
future problem from occurring.
Most of us do this every year or so when we get our
cars serviced, their usually isn’t anything wrong with
the car in its current state but if the oil, filters, spark
plugs aren’t replaced now then they might cause a
problem in the future.
Reactive Maintenance
Reactive Maintenance



Reactive maintenance is the process when a problem is fixed
after it has occurred.
If you get a flat tyre and get it replaced its reactive
maintenance.
If your monitor explodes then you replace it.
Preventative Maintenance




Electrical damage can be prevented using surge
protected power boards and uninterruptable power
supply (UPS)
Environmental damage can be prevented by using
good ventilation and air-conditioning.
Data lose can be prevented by backing up user
data and configuration files as well as
implementing anti-virus software.
Software issues can be prevented by keeping
software updated with patches and service packs.