Replacing PC Parts
The Laptop Repair Workbook
Copyright 2008 by Morris Rosenthal
All Rights Reserved
Replacing the motherboard
Illustrated How to Install a Motherboard
The process of replacing the motherboard began with
removing the old motherboard. Now it's time to
compare the old motherboard with the replacement motherboard to see how the
physically match. I've pulled the I/O core shield out of the back of the
case, and I've placed it on the I/O core of the old motherboard. You can
see (if the flash isn't blinding you:-) that the old I/O core didn't have
a game port or integrated sound, which the new motherboard supports. New
motherboards should always ship with their own I/O shield, but with a second-hand
replacement like we're using here, you have to make due. Fortunately, the
old I/O shield has punch-outs in the proper locations.
You'll need to exercise a bit of common sense when removing sharp pieces
of tin from a flimsy shield. While pliers may seem like a good idea, you
want to control the amount of force carefully, it doesn't take much to stretch
the shield so that it will never fit on the motherboard I/O core properly.
I worked the game port cover out with my fingers, and now I'm using a screwdriver
to pop out the tabs over the sound jacks for mic, line and speakers. Once
the metal tab is standing up, one or two bends is enough to break it off.
After we double check that the I/O shield now fits over the new I/O core,
we install it in the case. It's always a two handed job, the only thing that
secures the shield is the spring force on the dimples around the edges, and
of course, the motherboard, once the ports protrude through the shield. You
need to get the shield firmly fixed in place because otherwise it will just
slip when you're trying to align the motherboard ports and making installing
the motherboard a pain.
Here I've stood the new motherboard up in the case to compare the locations
of the holes in the motherboard with the standoffs in the case. In this
particular instance, it happens that all seven of the installed standoffs
aligned properly with holes in the motherboard (thanks to a standard ATX
form factor) so we didn't have to do anything. The main trick is to count
the standoffs before installing the motherboard, count out a like number
of screws, and make sure you use all of them to secure the motherboard.
The motherboard is installed into the case on an angle, with the back edge
and the I/O core going first. Once the I/O core is properly aligned with
the shield, you can push the ports through the openings and set the motherboard
down on the standoffs. Check for wires and cables having been caught below
the motherboard before you start securing it with screws.
We counted out seven screws to match the number of standoffs in the case,
and now we are going to use every one of those screws to secure the motherboard.
If there's a screw leftover when you're done, it means that there's a metal
standoff that didn't end up under a hole in the motherboard, and is probably
waiting for you to plug in the power and burn up the replacement motherboard.
In other words, if you didn't use up all the screws, take the motherboard
back out and count again. If you counted right, you need to visually inspect
the motherboard and the standoff locations, figure out which one isn't being
used, and remove it.
I like to make the most important motherboard connection first, and that's
the power switch. It's normally labeled "PW SW" or "Power SW" and the motherboard
will be labeled with "PW SW", "P-ON" "PW" or something similarly cryptic.
You won't hurt anything if you attach the power switch to the wrong connector
in the block, but you won't get the PC to turn on either. I went ahead and
connected the rest of the front panel leads to the motherboard, but you really
don't need to. Nobody uses reset switches or keyboard locks anymore, most
motherboards have a built in piezoelectric speaker, and who cares about LED's.
Now it's time to load the adapters back in, in no particular order. I did
the PCI adapters first, starting with the modem, and I even reinstalled the
sound card even though the replacement motherboard had integrated sound.
Last was the AGP adapter, which fortunately was compatible with the new
motherboard. If you were were doing a serious motherboard upgrade, with PCI
Express or AGP 8X video, you'd need a new video card as well.
As soon as all the adapter are in place, secure them all with a single hold
down screw on the back rail. It pays to do them all at once since the exact
dimensions of each card and motherboard vary a little, which means if you
installed the adapters and secured them one at a time, you might have to
loosen the screws up later to get another adapter to seat in the motherboard.
Just make sure you inspect the way the adapters are seated in the motherboard
when you're done, that inserting the screw didn't force the back of the adapter
down so far that the front popped out, especially with AGP cards.
Standard ATX motherboards all use the 20 pin ATX power connector, but newer
motherboards for Pentium 4 and Athlon 64 will always require at least one
more connection, often a 2x2 12V header, sometimes an addition 1x4 lead,
as the type used for the drives. I actually cover building PC's with Socket
775 for Pentium 4 (including 46 bit and forthcoming dual core) plus Athlon
64 in Socket 939 (also supports dual core athlon) in the 4th edition of "Build
Your Own PC," which I write for McGraw-Hill.
All that's left is reconnecting all the drive cables, power and data, that
we undid when removing the old motherboard (left). The recent ATA ports are
color coded for use with 80 wire cables and auto selecting master/slave on
ATA drives. If you have serial ATA (SATA) drives, it's even easier, just
one slim data cable per drive. Plenty more details for the individual component
is available in the other replacing parts pages on this site if you get a
little lost. Below we finish the job off with a cable tie, just to neaten
up the case a little and encourage better air circulation. That's what I've
got on how to install a motherboard.
Replacing the motherboard is about the most expensive and complicated step
you can take, so you want to do your homework first to make sure a new
motherboard is required. Computer Repair with Diagnostic Flowcharts is 100%
dedicated troubleshooting, so you can minimize wasted time and money. The
120 page printable eBook version with 17 flowcharts and text can be
instantly downloaded anywhere in the world for
$9.95, or a tiny fraction of what you'll spend on replacing a motherboard
that may not need it.
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