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 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.

Don't rush to replace anything until you troubleshoot the motherboard!