Step By Step Mainboard installation
Unplug everything from the computer: power cords,
keyboard and mouse cables, the monitor cable, Zip drives, etc.
Before you open the computer case, discharge any static electricity that you may have
built up. (Touch a doorknob, the metal part of a desk, anything to ground yourself and
discharge the electricity.) Even the smallest spark of static electricity can fry a
circuit and ruin a board.
Once the case is open, make a rough sketch of the PCs inner workings. Now start to
disconnect the wires and cables that connect the myriad of components to the motherboard.
You will find three types of wires in the motherboard: wires that supply power, wires that
transfer data, and wires that turn indicator lights on and off.
Power wires will run from the power supply to the motherboard, diskette drive, and some
expansion cards in the expansion bus, such as the diskette drive controller.
Not all devices draw power from the power supply. Some, such as the video controller, will
take all the power they need from the expansion slot socket. If your computer uses a small
fan to keep the microprocessor from overheating, a small power lead will run from the
motherboard to the fan.
Data transfer wires connect the disk drives to the motherboard.
Wires connect some devices inside the computer to indicator lights on the exterior of the
computer. For example, a wire leading from the drive controller indicates when the hard
drive is downloading data to the microprocessor.
Every time you disconnect a wire or a cable, make a note on your sketch. Each note should
The location of the motherboard connector or expansion board to which the cable or wire
was attached. With the exception of the larger connectors for the ribbon cables, there
should be a small mark on the motherboard. Some will be labeled plainly, such as Pwr
LED for the connector that leads to the Power light on the front of the
case or Spkr for the connector to the internal speaker. Some will use more
cryptic labels, such as J7. Any marking on the cable or wire plug, such as
Spkr or Pwr LED should be noted as well as the color and number of
the wires for each connector.
This information will help you when you are reconnecting the wires and cables to the
proper plugs after you install the motherboard.
any expansion cards from the old motherboards expansion bus. Unscrew the plate that
holds the expansion cards to the back of the PC case, then lift them up and out of their
sockets. Be careful with these cards--you will almost certainly need to reseat them in the
You also can reuse the older motherboards SIMMs or DIMMs in many of todays
newer motherboards. If you are reusing your old memory, remove it from the motherboard as
follows. There should be a tab at each end of the module, holding it into the socket. For
the SIMM modules, pull the tab away and tilt the module back until it pops up slightly out
of the socket. Remove DIMM modules by pushing the tabs straight down until the module pops
out of the slot, then simply lift the module out.
Most likely, youll also need to remove the power supply, a hard drive, a diskette
drive, a CD-ROM drive, or any combination of these devices before you can remove the
Find the bolts that hold the motherboard to the case. There will only be two or three. Now
youre ready to remove the motherboard. This is a bit tricky. Although screws hold
the motherboard firmly to the case, small stand-off posts or spacers keep the
motherboard from touching the case and creating electrical short circuits. The posts fit
in a hole-and-slot socket in the case, so you have to slide the motherboard out of
the slot before you can lift the posts out of the hole.
Small plastic tabs keep the stand-off posts from
slipping out of the holes in the motherboard. Once you have the motherboard out of the
case, use needle-nosed pliers to depress the tabs on the posts, then pull the posts
through the bottom of the motherboard. (Be careful. The bottom of the motherboard has lots
of small sharp wire ends that can cut your fingertips.)
Before installing the stand-off posts on the new motherboard, test fit the motherboard by
lowering it into the case to see where the holes for the spacers and the screws line up.
Check how the expansion slots and mouse and keyboard sockets line up with openings in the
Dont be concerned if the new board is smaller than the previous motherboard
(particularly if youve moved from an AT to a baby AT-style motherboard). As long as
all of the holes and sockets on the new motherboard line up with appropriate holes in the
case, youre in good shape.
Look over your new motherboard and make a rough sketch of the connectors and sockets that
will connect it to your hard drive, power supply, etc. It will be a lot easier to read the
small type on the motherboard now than after youve installed it in the case. If your
motherboard came with a schematic diagram showing the connectors and sockets, compare it
to the motherboard .
Youre ready to install the new motherboard. Insert the new microprocessor in the
motherboard and install the old memory.
Insert the stand-off posts by pushing them up through the bottom of the motherboard until
the plastic clips snap into place. Lower the motherboard into the case so the posts fit
into the appropriate mounting holes, then slide the board until the spacers are snug in
the slots. Screw board in place.
Replace the power supply, hard drive, and any other components that you removed from the
case to take out the motherboard.
Reattach the wires and cables to the motherboard. Use the notes you made during
disassembly to identify the wires and cables, then insert them into the appropriate
connectors on the motherboard.
Dont be surprised if you have a few wires with no sockets, especially if you have a
3- or 4-year-old computer case. Older PCs had a turbo switch that could be
used to speed up the motherboards internal clock and had two sets of wires; one
connecting the switch to the motherboard and another connecting the motherboard to a light-emitting
diode (LED, indicator light) to show whether the turbo function
was turned on. New PCs automatically operate at the fastest clock speed, so these sets of
wires arent accounted for on new motherboards. Just tie them in a knot so they
wont touch the motherboard and push them out of the way.
Your new motherboard may be equipped with built-in circuits that control communications to
the disk drives, monitors, and external speakers. What you do next depends on whether you
want to use these built-in controllers or use controllers that plug in to the
If you use the built-in controllers, life is easy. Install the ribbon cable attached to
the disk drives to the disk drive controller socket on the motherboard. Plug the monitor
cable and speaker wires to the sockets on the back of the computer case.
If you dont use these built-in controllers, life is a bit more difficult. Start by
inserting the controller cards into sockets (slots) on the new
motherboards expansion bus. Screw the metal plate at the rear of the controller card
into the case. (This simply keeps it from wiggling around and coming loose.)
Youre not done yet. The CMOS chip on your new motherboard expects to use the
built-in controllers. If the hard drives, etc., are not plugged into the onboard
controller, CMOS wont know where to find them and will act as if they dont
That means youll need to disable these devices, then reinstruct the CMOS
where to find them. To disable the onboard controllers, consult the technical documents
that came with the new motherboard. If the documentation doesnt provide the
information you need, its time to call the technical support number for the
Sometimes, disabling a controller may require moving tiny jumpers (which
connect two or more wires to complete a circuit) or flipping dual in-line package (DIP)
switches. But with todays motherboards, its unlikely youll ever touch a
jumper or a DIP switch. Its more likely that youll reconfigure the motherboard
using the CMOS when you boot up the PC for the first time.
If your new motherboard doesnt have built-in controllers, simply reinstall your old
controller cards. Remember to connect wires from the power supply to the controller cards.
Next step is to GET CONNECTED (click here)