Learn
How To Diagnose Power Supply Problems
by: Otis F Cooper
The Power Supply convert's your regular
household current into low DC voltage used by the computer. When this component
fails,there is simply no activity going on wih your computer.Remember to
do the easy troubleshooting first.Inspect the Power Supply for any damage.Double-Check
all connections.
Learning how to check your power
supply and how to replace it when needed can be a life saver if you're
a computer buff or in business with the trusted PC.Don't take for granted
the simple pleasure of turning on your PC and everything works just fine.
We turned on one of our computers
recently and in about one hour,it just re-booted itself.And it continued
doing so about 10 times a day until we found out the power supply was the
culprit.Things to look for when your power supply is going bad or just
dies on you are the following.
NO POWER TO THE COMPUTER
Here you must first check the wall
outlet for power by connecting another device such as a radio or lamp to
be sure power is present.If the computer is connected through a surge protector,check
it as well.
If the wall out has power,check the
power cable going to the PC to see if AC voltage is making its way to the
system unit.Do this with the use of a multimeter.
If there is power,you will have to
open the PC and check for power from the power supply to the motherboard.
When using a multimeter to check
voltage,be sure you have a good ground for the black lead of the multimeter.
RE-BOOTING PROBLEMS
One main problem you may face with
an ailing Power Supply is that it may re-boot the computer without any
warning.All information is lost and it seems as though this happens at
the worst possible time.
Booting errors when the computer
first start's up is another indicator of this component going on the blink.
POWER DISTRIBUTION PROBLEMS
When the power supply begins to fail,you
may receive power at one device and not another.For example,the Hard Drive
may receive power but the CDROM Drive has nothing at all.
Another headache with would cause
re-booting is the intermittent power going to the drives or the motherboard
itself.Follow the steps below to check your power supply should you experience
some of the above problems.
CHECKING THE POWER SUPPLY
If the wall outlet,and the power
cord are good,make sure the connection at the motherboard is secure.Then
you may have to face the fact that the power supply itself is bad.If you
have a Multimeter you can test the power supply output before purchasing
a new one.Simply follow these steps.
Turn off the PC,but do not unplug
it,open the system unit. Set the multimeter to read DC volts in the next
range higher than 12 volts.Locate a power connector similair to the hard
drive,or cdrom drive connector that is unused and turn on the PC.
You can also unplug a drive connector
and use it as well.Turn on the PC and insert the BLACK probe into the power
connector on one of the BLACK wires.Touch the RED probe to the YELLOW wire
on the power connector.
The multimeter reading should be
+12 volts Now touch the RED probe to the RED wire and the reading should
be +5 volts.If no readings or different readings occured,you'll have to
replace the power supply.If the readings were correct,you should check
the P8 or P9 connectors at the motherboard. These connectors may also be
named P4 and P5.To check these connectors,perform the following...
Insert the BLACK probe into P8 at
one of the BLACK wires. Insert the RED probe into the P8 connector at the
RED wire. The reading on the multimeter should be +5 volts
Check the power going to the Motherboard
connections by inserting the RED probe into P8 at the YELLOW wire and you
should get +12 volts.Leave the BLACK wire touching the black wire at the
P8 connector.Check the BLUE wire and the reading should be a -12 volts.
Now move the BLACK probe to the BLACK
wire on the P9 connector.Test the WHITE wire by inserting the RED probe
and the reading should be -5 volts.Check the RED wires on the P9 connector
and you should get +5 volts on each red wire.You won't get exactly 5 or
12 volts but the readings will be very close, such as 5.02 volts.
If the Power Supply is a couple of
volts off,in either direction,such as when the RED wire should be reading
-5 volts but it reads -8 volts,or if there are no readings,replace the
power supply.
DO NOT remove the power supply from
the system unit case when performing these tests.DO NOT perform these tests
if you do not feel comfortable.Be sure to remove any and all electrical
static build-up from your clothes and body BEFORE touching any parts inside
the system unit.And NEVER open the power supply case for any reason,since
high voltage may be present.
About The
Author
Otis F. Cooper is solely dedicated
to boosting the knowledge and confidence of every computer user that is
serious about knowing computers.Use his informative articles and videos
to understand every aspect about the PC. Read more about his formula for
pc training at http://www.ultimatepcrepair.com
allaboutpc@juno.com
Courtesy of http://www.ArticleCity.com/
