Upgrading Motherboard

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62UPGRADING A

MOTHERBOARD

For the great majority of personal computers in the marketplace today, the motherboard(also called the main board) represents the single, most complex and expensive sub-assemblyin the system. The motherboard contains the core processing elements (i.e., the CPU,main chipset, cache, and RAM), manages the system resources, such as IRQ lines andDMA channels, and supports the system’s expansion bus architectures (i.e., ISA, VL, andPCI). More than any other part of the PC, a motherboard defines the capabilities and over-all performance of a system.

As a PC ages, however, the motherboard limits the system’s upgradeability. True, youcan add RAM and upgrade a CPU. Although these tactics can prolong the working life of

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CONTENTS AT A GLANCE

Considering the UpgradeThe pros and cons of traditional upgrades

The pros and cons of proprietary daughtercard upgrades

The pros and cons of processor card upgrades

Performing the UpgradeStatic precautionsSave your CMOS

Prepare the systemRemove the original motherboardMachining changesInstall the new motherboardRe-assemble the systemTesting the system

Troubleshooting the Upgrade

Further Study

older systems, they have a limited impact on the overall performance of a motherboard(especially older i286 and early i386 motherboards). As PC technology surges ahead andthe price of advanced motherboards continues to drop, replacing an outdated motherboardoutright is becoming an ever-more cost-effective upgrade option. This chapter illustratesthe most important concerns when planning a motherboard upgrade, walks you through anupgrade process, and shows you how to deal with typical upgrade problems.

Considering the UpgradeUpgrading a motherboard is not particularly difficult, but it is a time-consuming, de-tail-oriented process. As a result, advance planning can be a substantial benefit. Thispart of the chapter covers the important points to keep in mind when planning a moth-erboard upgrade. As with any upgrade, call around and find the best price and deliveryterms. Given the added expense of a motherboard, you should find a vendor with a lib-eral return policy, just in case you accidentally obtain an incorrect or defective (“deadout of the box”) replacement:

■ Compare the features All motherboards are not created equal, so check the specifica-tions closely before making a choice. BIOS now plays a vital role in such advancedfeatures as Plug and Play, APM, EIDE and Ultra-ATA support, USB support, boot sec-tor virus protection, and so much more. The move toward PC power conservation (re-ferred to as green PCs) is resulting in features like ACPI. The amount of cache has agreat impact on CPU performance. The number and type of I/O slots defines systemexpandability. Most modern motherboards provide on-board features, such as drivecontrollers, video adapters, and COM ports. If your major interest is enhancedvideo/multimedia performance, a Pentium II motherboard with a single AGP bus slotwill probably do the trick.

■ Check the motherboard dimensions and mounting points You cannot overlook the nutsand bolts involved in a motherboard upgrade. Unfortunately, this is often the most dif-ficult (and neglected) consideration. First, the physical dimensions of the motherboardmust fit within the space currently available in your PC. A smaller motherboard is gen-erally not a problem, but a larger (or oddly shaped) motherboard will invariably en-counter interference from drives and the power supply. The other issue is mountingholes. Chances are very good that mounting holes on the new motherboard will notmatch the original mounting holes.

The use of ATX and NLX motherboards and cases goes a long way to easing the prob-lems of dimensioning. Because ATX and NLX form-factor motherboards, cases, andpower supplies are all designed to be interchangeable, moving to these form factors cangreatly ease the upgrade problems associated with physical motherboard mounting.

1570 UPGRADING A MOTHERBOARD

If you elect to replace a “full AT” or “baby AT” motherboard with an ATX or NLX mother-board, you must also upgrade the case and power supply as well.

■ Check the CPU location vs. your expansion slots Check the sales literature or onlineproduct documentation for the new motherboard and find the location of the new CPUrelative to the expansion slots. Because it is assumed that you will be upgrading yoursystem to a Pentium, Pentium MMX, or Pentium II motherboard, the use of a CPUheatsink will be mandatory. As a result, the CPU/heatsink combination could easily in-terfere with the installation of one or more expansion boards—this could be a real prob-lem if your current system is heavily loaded. Try to pick a motherboard that places theCPU out of the way of expansion boards. For ATX and NLX motherboards, the CPU’splacement normally does not interfere with the expansion slots.

■ Consider collateral upgrades Before finally committing to a new motherboard, take amoment to evaluate the other sub-assemblies found in the PC and anticipate any otherimmediate upgrade needs. How old is the hard drive? Do you need a 3.5” floppy drive,CD-ROM, or even a DVD-ROM? Will an SVGA video board be added? Each of these“added extras” will boost the ultimate cost of the upgrade that much higher, so it is al-ways worthwhile to compare this “adjusted” cost against the purchase price of a simi-lar PC available “off the shelf.” In some cases, it might be in your customer’s bestinterest to simply buy or build a new PC outright.

■ Check the costs Choose your new motherboard carefully using a balance between priceand “cutting-edge” features. New motherboards are expensive, and top-of-the-linemotherboards will always be pricey, but you can usually find a great deal if you look 6to 12 months back. For example, a new Pentium II motherboard (with the Pentium IIinstalled) can easily run over $800, while a recent Pentium/Pentium MMX mother-board (plus CPU) can be had for well under $400. The idea is that you can save a bun-dle of money if you can make due with upgrades that are just slightly off the cuttingedge.

Perhaps even more important, be sure you are aware of any “hidden” costs with themotherboard. For example, be sure that you know whether or not the new motherboardcomes with current BIOS, a CPU, and CMOS backup battery. If you plan to be runningsoftware that demands a math co-processor, see that the CPU has an adequate floating-point unit built in. Also, find out how much RAM is on the motherboard and see if yourcurrent RAM is compatible—you might find yourself buying 32MB to 64MB of newSIMMs or DIMMs because you can’t transfer the memory from the old motherboard to thenew one. This will bump up the cost of the upgrade by at least several hundred dollars.

THE PROS AND CONS OF TRADITIONAL UPGRADES

Motherboard upgrades provide a much more sweeping and comprehensive improvementin system performance than changing any one element on the original motherboard itself.A new motherboard not only upgrades the CPU, it provides better caching, space, and sup-port for larger amounts of faster RAM (such as SDRAM), advanced bus slots for addedsystem performance, and superior data handling through the use of current BIOS andstreamlined, highly integrated chipsets. Although new motherboards are generally re-garded as the best way to rejuvenate an outdated system, motherboards are expensive. Ifyou are upgrading from an i486 or early Pentium motherboard, you will need a new CPU(and probably new system RAM) in addition to the motherboard itself. Such upgrades can

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also consume a fair amount of time (sometimes an hour or longer), depending on theamount of mechanical disassembly that is required. The other disadvantage is that ofphysical incompatibility. If the mounting holes on a new motherboard do not align withthe original mounting standoffs, new mounting holes will have to be created (which fur-ther lengthens the upgrade time).

THE PROS AND CONS OF PROPRIETARY DAUGHTERCARD UPGRADES

The two great drawbacks to motherboard replacement are price and time. Some compa-nies, such as Compaq, addressed these disadvantages by designing a modular mother-board—a unit that mounts the CPU, cache, and often the system RAM on a readilyaccessible module, referred to as a daughtercard. The daughtercard can be replaced inonly a few minutes, with no real disassembly required. Because the daughtercard isspecifically designed to carry the core processing components, an upgrade can easily yielda 100% to 600% performance improvement. These are compelling advantages—espe-cially when a large number of systems need to be upgraded. The problem with daughter-cards is that they are proprietary devices that must be designed to mate with a specificmotherboard. As a result, a daughtercard is generally quite expensive—sometimes morethan a conventional motherboard. Daughterboard upgrades also prevent new bus archi-tectures from being introduced to the system.

THE PROS AND CONS OF PROCESSOR CARD UPGRADES

Older bus-mastering systems (such as the PS/2) have found another alternative to mother-board upgrades. Instead of taking the time to replace the main motherboard assembly, Micro-Channel systems allow a supplemental CPU board (called a processor card) to be installed inany available expansion slot. Because the MicroChannel architecture allows bus-mastering,the processor card can take over system control from the CPU resident on the motherboard—effectively shutting down the original CPU—and provide a CPU enhancement of 200% ormore. As with any expansion board, the processor card can be configured and installed in amatter of minutes. On the down side, a processor card is still rather pricey when comparedto another CPU itself and more expensive than a conventional motherboard. Althoughprocessor cards are more “standardized” than daughtercards, they are generally limited toMCA systems. ISA and PCI systems typically do not incorporate this design philosophy.Processor cards also do not support the introduction of new bus architectures into a system.

Performing the UpgradeUnlike CPU or expansion-card upgrades, replacing an entire motherboard is a rather in-volved process that requires a substantial amount of care to be accomplished successfully.This part of the chapter covers the essential steps and precautions that you will need to re-member during the upgrade. Before starting the upgrade, it is a good idea to run a bench-marking program, such as PC Tools System Info, and notice the system-performancebenchmark figure—this gives you something to measure the system against once the up-


grade is finished. You are also strongly urged to perform a complete system backup be-fore proceeding—collateral system damage during an upgrade is a serious possibility.

STATIC PRECAUTIONS

Most of the ICs used in today’s computers are fabricated with technologies that make themextremely sensitive to ElectroStatic Discharge (ESD). To ensure the safe handling of moth-erboards and other system components during the upgrade, take the following precautions.First, invest in an anti-static mat that is large enough to cover a majority of your work area.See that the anti-static mat is properly cabled and attached to a reliable earth ground. Underno circumstances should you allow a motherboard to rest on a synthetic or static-prone sur-face. Second, use an anti-static wrist strap whenever handling components or tools insidethe PC. Cable the wrist strap to the anti-static mat or to another reliable earth ground. Third,always try to handle printed circuit boards by their edges—avoid touching the individual ICpins or printed wiring. Fourth, have a supply of good-quality anti-static bags on hand tohold the system’s expansion boards as they are temporarily removed. Finally, excessivelydry environments tend to allow substantial buildups of static charges in objects, clothing,and bodies. If it is possible, try to work in an environment with at least 40% humidity.

SAVE YOUR CMOS

Before starting your upgrade, make it a point to obtain a current record of your CMOS set-tings. You can do this by taking <PrintScreen> shots of each CMOS setup page, you canphotocopy and fill-in the CMOS configuration form at the back of this book or you can useany of the CMOS-related software utilities on the companion CD. You should be partic-ularly interested in the hard-drive setup information because you will certainly need toload that data into the new motherboard’s CMOS before the system will recognize yourboot drive. Once you have the CMOS information, set it aside in a safe place.

PREPARE THE SYSTEM

At this point, you can prepare the system for its upgrade. Be especially careful of screw-driver blades when working inside the PC. If you should slip, the blade can easily gougethe motherboard and result in broken traces. It pays to be careful and gentle when up-grading a motherboard. Before you even consider opening the PC cover, turn the systemoff and unplug the cord from the ac receptacle. This helps to ensure your safety by pre-venting the PC from being powered accidentally while you are working on it.

Remove the screws holding down the outer cover and place those screws aside in a safeplace. Gently remove the PC’s outer cover and set it aside (out of the path of normal floortraffic). You should now be able to look into the PC and observe the motherboard, alongwith any expansion boards and drives that are installed. Now that you are looking at thecomplete PC, this is the time for you to label things. Clearly marked labels will help youremember the purpose of each cable (e.g., power, drives, key lock, speaker, drive light,etc.) and show you where each item went on the original motherboard or on various ex-pansion boards. Don’t be afraid to label things. Labels need not be fancy—a roll of mask-ing tape and an indelible marker are all that is required. Remember that you’ll have to takethis all apart, so anything that will help you remember where things go will be an asset.

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REMOVE THE ORIGINAL MOTHERBOARD

At this point, begin clearing the obstructions to the motherboard. Start by removing eachexpansion board. Place each board into an anti-static bag and set each bag aside on theanti-static mat. Next, remove any cables that are attached to the motherboard (such as thekey lock or speaker cables). If floppy-drive and hard-drive cables are connected to themotherboard, remove them as well. Finally, disconnect the power cable(s). For AT-stylemotherboards, you’ll find two 6-pin power connectors from the power supply. For ATXmotherboards, you’ll find a single 20-pin power connector. If drives or chassis assembliesare interfering with the motherboard, remove them now and set them aside carefully.

You should now have an unobstructed view of the motherboard. Locate and removeeach of the six (or more) screws that hold the motherboard in place. Once each of thescrews have been removed, gently lift out the motherboard and lay it aside onto the anti-static mat—preferably in its own anti-static bag (the whole board should fit on the mat).The motherboard should lift out without difficulty. If the motherboard does not budge orlift out easily, you might have overlooked a screw or cable. Do not force the motherboard!Often, one or more white nylon standoffs is still clipping the motherboard in place. Care-fully locate the obstruction and clear it properly.

MACHINING CHANGES

If you are very fortunate, you might be able to obtain a new motherboard with screw holelocations that are identical to those of the original board. In that case, you can simply dropdown to the next step and proceed to install the new motherboard. If not, life gets a bitmore complicated. That new motherboard has to be secured to the chassis to ensure astrong platform for adding the expansion boards more than for electrical grounding. Anybending or flexing of the motherboard can result in failures.

The general solution in this case is to mount threaded, non-conductive standoffs to themotherboard, then position the motherboard so that expansion boards would be positionedproperly against the rear of the machine. Mark the location of as many standoffs as possi-ble, then drill new holes just big enough to accommodate screws inserted from under thechassis. If you must drill new holes, drill slowly and carefully to prevent sending metalshrapnel all over the PC. You can then vacuum any metal particles with a static-safe vac-uum. Notice that you do not have to place a hole for every standoff, just three or four—enough to hold the motherboard securely in place. The remaining standoffs will simplyserve to keep the motherboard rigid.


NLX motherboards do not carry any of the burden found in AT-style or ATX mother-boards—all of that peripheral equipment is attached to the NLX “riser card.” You needonly detach and unplug the NLX motherboard from its riser card.

After you remove the original motherboard, you should also remove the CMOS backupbattery and place it into a heavy-gauge plastic bag before storing the original mother-board. This will prevent an aging CMOS backup battery from rupturing and damagingthe original motherboard.

INSTALL THE NEW MOTHERBOARD

You can now place the new motherboard into the chassis and secure it into place. Do notuse excessive force when tightening the screws—excessive force can cause the mother-board to warp and result in failure. When securing the board, check that no metal bracketsor standoffs can touch the new motherboard and cause a short circuit. It is usually recom-mended for you to use a thin, non-conductive washer between each standoff and the moth-erboard. Once the new motherboard is installed mechanically, you can start re-assemblingthe system.

Refer to the user’s guide that accompanies the new motherboard and check each jumperor DIP switch. This is a particularly important step because many contemporary mother-boards provide services right on-board that have traditionally been assigned to expansionboards (such as video adapters and drive controllers). For example, if you used a dual se-rial port board with your original motherboard, but your new motherboard provides twoserial ports, you won’t need the dual serial port board. If you need to use that board, youwill have to set motherboard jumpers to disable the on-board serial ports. The same thingis true of video adapters. If an SVGA port is available on the new motherboard, but youhave a 3D graphics accelerator board on-hand, you will have to disable the on-board videoport to prevent a hardware conflict. If the new motherboard provides a floppy and IDEcontroller, you can abandon that drive-controller board and plug the drives right into theappropriate connectors on the motherboard. In that case, check the drive-control jumpersto be sure they are enabled. Be sure to review each available jumper carefully. Also ver-ify that the motherboard’s bus speed, clock multiplier, and CPU voltage settings are allconfigured properly for the CPU.

RE-ASSEMBLE THE SYSTEM

Once the motherboard jumpers are set, you can install the CPU, system RAM, andpower/case cables. CPU installation should go easily, but the CPU must be oriented prop-erly in the socket relative to pin 1. Chances are that the CPU will require a heatsink/fan,so be sure to install it securely (along with thermal compound to improve heat transfer be-tween the CPU and heatsink/fan assembly). If you need to install the BIOS IC(s), youmight do that next. Be careful to orient each BIOS ROM properly, relative to pin 1. If ithas more than one BIOS ROM, be sure to install IC1 and IC2 in their proper places. Re-versing the BIOS ROM locations should not damage them, but the system will probablynot boot. The new motherboard will need a backup battery to support the CMOS/RTC IC.If a battery is not already on the new motherboard, install a new battery (or re-connect theoriginal battery pack).

Be sure that each SIMM snaps gently into place. If they do not, they might be insertedbackward. When inserting cables, note that the red strip on each ribbon cable is pin 1. Besure that pin 1 on the cable is matched to pin 1 on the corresponding connector. Insertinga ribbon cable backward is rarely damaging, but it might prevent the system from booting.

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Most current motherboards and case styles are now relatively compatible, so youshould not manually machine the case unless it is absolutely necessary. ATX and NLXmotherboards should be drop-in replacements, which require no machining under anycircumstances.

Re-connect the power cables. Finally, install the expansion boards that you will need inthe system. Remember that you might not need all of the adapter boards you started withif the motherboard will be taking over particular functions. If you had disassembled anydrives or chassis sub-assemblies before removing the original motherboard, be sure to re-assemble any of those items now and check that their power and signal cabling are secure.Reconnect any ancillary devices, such as the mouse, keyboard, and monitor.

TESTING THE SYSTEM

At last, you will face the “moment of truth.” If things have gone well, this procedureshould have taken no more than an hour. Once the components and cabling are all secure,it will be time to re-connect the ac line cord and try applying power to the system. Be surethat your hands and any tools are clear of the PC. Turn on the monitor, doublecheck yourpower-cable installation one more time, then go ahead and hit the power switch.

After a moment or two, you should see a BIOS message appear on the monitor. This isa good sign. When the POST displays its message asking to start the SETUP procedure(usually by pressing the F1 key), go ahead and start it. Review each screen in the Setuproutine and restore as many CMOS settings as possible (especially the memory amount,floppy-drive types, and hard-drive configuration). Chances are that several Setup vari-ables were not in the original system. Just leave these in their default states for now—youcan always optimize them later. Save the CMOS setup and reboot the computer. Your up-graded system should now complete its POST successfully and boot to DOS, as expected.Congratulations, you have completed your motherboard upgrade.

When the system boots as expected, the last step should be to power-down the computerand re-assemble the outer housing. You can then run your benchmarking program again(such as PC Tools System Info) to determine the new benchmarks for your PC. You cansee the relative improvement in performance over that of the original system.

Troubleshooting the UpgradeUnfortunately, motherboard upgrades are frequently fraught with problems. The sheernumber of jumpers, DIP switches, cables, and CMOS settings often present problems forthe novice. This part of the chapter outlines a series of problems and solutions that typi-cally plague motherboard upgrades. If you need additional technical or troubleshootinginformation for motherboards, refer to Chapter 28.

Symptom 62-1. The motherboard is installed, but the system won’t bootThis is a classic sign of installation problems. Start with the basics. Check all of the ca-bles and connectors—especially the power connectors. Also be sure that no metal stand-


If you cannot adequately reconfigure the CMOS setup, select the “BIOS defaults,” whichshould plug in the variables necessary to get the PC working. You can then tweak theCMOS values later to improve system performance.

offs or brackets are shorting the motherboard from underneath. Next, check for any wiringor cables that might be installed backward. Although this will rarely keep a PC from boot-ing, it is possible. Be sure that pin 1 on each cable aligns with pin 1 of each connector. Fi-nally, doublecheck the socket-mounted ICs, such as the CPU, BIOS ROM(s), and SIMMs.They should all be aligned properly, inserted evenly and completely. If you locate an in-correctly installed IC, it might be damaged. Remove it from the motherboard, check it forbent or broken pins, reinsert it correctly, and try the motherboard again. If the IC is dam-aged, it should be replaced.

Symptom 62-2. The motherboard starts, but it will not boot from the harddrive or recognize the correct amount of RAM in the system You might seean error message, such as “CMOS error: press <F1> to run Setup.” This error generallyindicates that the motherboard is working, but the system CMOS contains incorrect infor-mation. Either you forgot to enter the new CMOS variables, you forgot to save the settingswhen you updated them, or the backup battery is not installed and CMOS contents werelost after the system was powered down. Check the backup battery first. If the battery isa coin cell, see that it is inserted properly and completely into its holder. If the battery is a“pack-type,” check to see that it is plugged into the proper motherboard connector in theright polarity. If the battery is installed correctly, try a new one. Run the Setup programand check each drive and memory setting. If you entered a drive parameter or RAMamount improperly, correct the settings and save CMOS again. Reboot the PC. If newCMOS settings are lost after the PC is powered down, the backup battery has failed—trya new battery.

Symptom 62-3. You cannot use one or more drives in the PC Either thedrive(s) have been entered improperly in the CMOS setup routine or the drive(s) are ca-bled improperly. Start by checking the CMOS setup. Be sure that proper references forthe floppy drives and hard drives are in the system. Fill in any missing information and re-boot the computer. If the CMOS settings are all correct, check the data cables and powercables at each drive—loose power or signal cables can easily disable a drive.

Symptom 62-4. The system boots and runs, but it locks up unpredictablyBe sure that the CPU and all system RAM is installed correctly and securely. Try reseat-ing the RAM. Check the system CPU for excessive heat. An overheated CPU can lock upwithout warning. If the CPU is fitted with a heatsink, be sure that it is securely attachedand that you have used ample amounts of thermal compound to aid heat transfer. If theCPU runs hot and there is no heatsink, try adding one.

Another factor to consider is the possibility of controller conflicts. For example, if avideo port is on the new motherboard, but you also have a video board installed in an ex-pansion slot, you will have to set jumpers to disable the motherboard’s video port. Thesame thing is true for drive-controller conflicts, as well as serial or parallel-port conflicts.Take another close look at the expansion boards in your system and be sure that the boardfunctions do not conflict with the functions provided on the motherboard.

Symptom 62-5. The system is active, but the video is erratic or absentCheck to see no video conflict is between the motherboard and a video expansion board.

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If a video port is on the motherboard, it probably should be disabled when an expansionvideo board is used in the system. Also check that the monitor is turned on and that thevideo cable is securely connected to the video port. If problems persist, check that thevideo board is installed correctly and that if extra memory must be excluded from the up-per memory area, the proper command-line switches are included with EMM386 in theCONFIG.SYS file.

Further StudyThat’s all for Chapter 62. Be sure to review the glossary and chapter questions on the ac-companying CD. If you have access to the Internet, take some time to review these moth-erboard upgrade resources:

Intel: http://www.intel.com

Supermicro: http://www.supermicro.com

Tyan: http://www.tyan.com


Documents

Upgrading Motherboard