I work in the PC repair industry and have many years of experience
diagnosing and troubleshooting PC problems. Judging by your
description of the problem, I am going to assume you are talking about
an x86-based system and not a Macintosh.
Troubleshooting boot problems like the one you are describing is
mostly a process of elimination. A computer's motherboard can identify
some problems by using a series of beeps. This is part of the Power-On
Self Test (POST) and takes places before the operating system is
booted. The fact that your computer is not completing POST (no beeps)
certainly indicates some sort of hardware fault. To narrow down the
possibilities, you'll have to open up your computer and investigate.
Please note that the following troubleshooting steps are what I would
do to troubleshoot this problem. If you have any doubt about your
ability to complete any of these steps, or are uncomfortable with the
idea of poking around inside your computer, I highly recommend you
take your system to an A+ certified hardware repair technician. It
will cost more, but it beats making the problem worse!
In addition, please take care regarding static discharge. Work on a
flat, non-conductive surface like formica or wood. Avoid working on
carpet or a metal desk. To further reduce the risk of a static
discharge, keep one hand on the computer's metal casing as much as
possible. You can even buy a "discharge" bracelet, which consists of a
conductive wrist strap that clips onto your computer's case. Remember,
a static shock equivalent to what you might get by stroking a cat in
the wintertime is several hundred times the power needed to fry nearly
every component in your system! You can NOT be too careful about this.
You will need a medium-sized Phillips (cross-head) screwdriver to get
into most computers. If you are opening up a proprietary brand like
Compaq you may also need a hexagonal-head screwdriver.
Before you begin, examine the monitor connector on the back of your
computer. If it is on a line with the rest of your systems connections
(mouse, keyboard, USB ports, printer port) then it is actually an
on-board video card, and the entire motherboard will need to be
replaced no matter which component went bad. If your monitor
connection is separated from the others (and it will usually be
aligned perpendicular compared to the printer port) then it is most
likely a separate card and can be replaced.
One final warning: many computer manufacturers will consider home
repair of a system a reason to void your warranty. If your computer is
still under warranty, DO NOT ATTEMPT TO REPAIR IT YOURSELF. Contact
the manufacturer for warranty information.
All set? Here we go...
The first step is to unplug ALL cables from the back of the machine.
Next, we need to get the case off. In newer computers, the left side
panel of the case (as you look at the front) will slide backwards and
come out when the screws are removed. In most older systems (and a few
newer ones yet) you must remove the entire case shell; the sides and
top are all one piece. Some models, particularly IBM and some early HP
systems require you to slide off the ENTIRE case shell (front, top,
bottom and sides). Take a look at your system and try to see how the
case comes off before you actually attempt to remove it. Your
computer's manual may help with this, too. The screws you'll need to
remove are usually located on the back of the case, along the outside
edge. Do NOT remove screws that are adjacent to the exhaust fan vent
and power plug. These hold the power supply in place and can be
difficult to replace if removed.
Once you've gotten the case off, you should have access to the
computer's motherboard. It may be pretty dusty in there; a bottle of
canned air will clear it out nicely. Plugged into the motherboard you
will see several wide, flat grey cables. These are data cables from
your hard drive, floppy drive and CD-ROM. Across the board from them
will usually be your system's CPU. It will have a large heatsink or
fan on it and should be the largest single chip on the motherboard.
Near this will be a connector, usually white, with a bundle of many
multi-colored individual wires plugged into it. The other end of these
will lead into the system's power supply, usually a metal box located
high in the rear of the case.
Below the system's CPU you will probably see at least one card. These
are easily recognizable by the fact that they stand perpendicular to
the motherboard and provide external connections on the back of the
case. The video card is usually in the topmost slot and will be the
card that your monitor plugs into. Expansions cards are generally held
in place with a single screw that fits into the card's backplate. Find
and remove this screw. Be careful not to let it drop onto the
motherboard! Now (after grounding yourself on the metal casing by
touching it), using a steady pull, remove the video card from its
slot. If it doesn't budge under moderate pressure, make sure there is
not a latch on the motherboard that is holding it in place. If there
is no latch and you can't pull the card out, try VERY gently rocking
it back and forth in its slot to see where it is hanging up. If you
simply cannot remove the card, DO NOT TRY TO FORCE IT! Replace the
card's screw, put the case back on, and head to a computer repair
shop.
Once you have removed the video card, set it some place safe and
non-conductive. Now replace the case (but don't screw it in yet) and
plug the system back in. Power it on and listen. If your system STILL
does not beep, then the problem is most likely your motherboard.
If your system DOES begin beeping after a few seconds, then the
culprit is your video card. Power the computer back off (you may need
to hold the power button in for several seconds before it will turn
off), remove the case again, and re-insert the video card (after
grounding yourself on the metal casing by touching it). If it doesn't
seem to be going in straight, make sure the backplate is not getting
caught somewhere. It may take a fair amount of pressure to get the
card back into its slot, but once again, DO NOT try to force it in.
Once you have the card settled in its slot, replace its backplate
screw, put the case back on, and power on the system again. If it does
not beep with the card re-inserted, then the problem is definitely
with your video card and it will need to be replaced. There is also
the off chance that your system will boot normally after re-inserting
the card. This means that it simply came unseated somehow, and that it
is now seated correctly.
If you still got no beeps with the video card removed, there are a few
possible causes:
First, make sure the system's speaker is plugged in! The internal
speaker is usually located near the front or bottom of the case and is
connected to the motherboard via a red and black wire pair. In some
cases, the speaker is embedded on the board itself, in which case it
will look like a squat black cylinder with a small hole in the top.
Another card (other than the video card) may be preventing the system
from completing POST. This is rare, but just to be sure, you can try
removing the rest of the expansion cards from your system in the same
manner as the video card, powering the system on once after removing
each card. If the system begins beeping after the removal of a card,
then that card is most likely the troublemaker and will need to be
replaced. If all cards are out, and the system is still silent, then
you will need to take it to a repair shop for professional
diagnostics.
It is also possible that the CPU or RAM chips have worked loose
somehow. However, reseating these components, particularly the CPU, is
a very delicate operation and I cannot in all honesty recommend that
you try it yourself unless you have a fair amount of technical
experience. These components are VERY sensitive to static discharge.
In addition, it is easy to crush or damage your CPU while trying to
remove the fan or heatsink that covers it. If you suspect that one of
these components (CPU, RAM, or motherboard) is bad, your safest
solution will be to take it to a repair shop.
This answer is intended to be a quick-and-dirty troubleshooting guide.
If you get the case off but cannot positively identify the components
mentioned above, do not attempt to follow these steps on your own.
The source of this information is my own experience. I've been
repairing PC-style systems for over 10 years and am confident of my
methods, but they say a picture is worth a thousand words. Below I've
listed a few links to video card installation guides that have several
pictures that may assist you in identifying your computer's
components.
An excellent guide to getting inside your case, with lots of pictures:
http://www.zdnet.com.au/reviews/computers/components/story/0,2000023499,20267937-2,00.htm
How to upgrade your own video card:
http://www.videocardupgrade.com/find_video_card.shtml
I hope this information helps you solve your problem! |
