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Since I first became involved with PCBUILD, so many years ago, I have considered a FAQ or series of articles to help the novice computer user understand and trouble shoot problems. It seems time for me to get to it. It will be in the form of a weekly newsletter posted here to our web site.
Now, with that said, this Newsletter is not intended for someone with an A+ Tech Certification or other advanced training in computer repair. I intend to start at the beginning, so it maybe a bit redundant for those with advanced skills.
It is time for my basic words of advice. If you have a newer computer, still covered under warranty, I want you to think long and hard before you take the cover off of the case. Often this will violate any existing warranty and you could be without the warranty if you are required to replace some of the parts.
The next point you need to consider is where you are going to work on your computer and static electricity. ALWAYS unplug the power cord from the case before you remove the cover. This does not insure that all dangers of electricity has been removed, it only insures that no power is running through the components. When you touch any components inside the case, a charge of electricity can move from you and course through the system. The best way to insure against this problem is to wear an anti-static wrist strap. That does not mean I always have one handy, so another approach is to touch the internal frame of the case to discharge any static electricity before actually touching any components. Remember that although the carpeted floor of your family room may seem a good ideal place for working on a computer, carpeting will create static electricity. I advise placing the computer case on a table, desk or workbench to avoid any such problems.
The last thing I will mention on the subject of static electricity is touching electronic circuitry on the motherboard, video cards, modems, sound cards, hard drives and so forth. It only takes a small effort to grasp components by the insulated areas, non-circuitry portions, and it will insure that you do not send a bolt of static electricity coursing through it. Remember even a small charge of static electricity blasting through most of today’s components is like a lighting bolt striking your house. It will damage the component and should be avoided at all costs.
I also want to mention handling of drives, hard drives in particular. Never drop a hard drive, even a few inches on to a surface. The armature and heads inside the hard drive rest but only micro-fractions off of the drive’s spinning platter. Even when the drive is at rest, dropping a hard drive onto any surface can cause the heads to dig into the platter, pitting it. Like wise, floppy drives, CD Rom drives, DVD drives, even zip and Jazz drives should be handled with extreme care. When handling them, gently place them down on a surface.
If you are still with me, then lets begin with the basics. The PC computer most people use today consists of only a few components and in actuality it requires only five components to post, the term for starting up and displaying information on the monitor. These components are:
- case with a power supply
- motherboard
- CPU
- Ram memory module(s)
- Video card
Remember these, as this is the basic configuration of all PCs. The computer will not boot or actually process data in this configuration, but it will start and display the pertinent information about the system. If later on you have a computer that will not start or post, remember you can strip the system down to these bare minimums in order for it to post. If it still will not post, then you have a severe problem and you may need to take the computer to a reliable technician.
You will need a drive of some sort in order for a computer to boot, or load the operating system. This drive can be a floppy disk drive, a hard drive or a CD Rom drive. But we will discuss this later.
Computer will not post (start)
We are going to deal with this issue first. It is the toughest issue for a diagnostician. The easiest way to solve this issue is with a diagnostics card like those available from Ultra-X. You simply insert the card in a computer slot, (either a PCI slot or an ISA slot), turn on the power and the card will give you a read out of codes displaying the problem. These cards cost many hundreds of dollars and a tool for a computer professional, so we will assume you are not going to buy one. *wink*
You should first remove all the cards, (sound card, network card, modem and so forth), from the motherboard. After each of these steps always try to turn on the computer. If it comes on, you have found your problem. Remember that solving most problems with a computer requires good common sense and a little deductive reasoning. Now remove the ribbon cables from the motherboard, cables running to drives, ports or other devices. This does not include the power connection wires or case LED light wires.
The first thing to check is that you have power running to the computer, is the wall outlet dead? The next thing to look for is the fan in the power supply coming on when you turn on the computer? If you are using an AT form factor power supply, the fan should at least come on. An ATX will probably not even turn on the fan if there is an issue. Now check to see if the power converter switch in the back of the case, from the power supply is set to your local power type supplied. In the USA, Canada and many other areas, that is 110volts. In Europe and a few countries elsewhere it is 220volts.
The power cables running to the motherboard from the power supply should be checked to see if they are properly seated. If it is an AT form factor, be sure that the two connectors have the black wires next to each other. Reversing these will cause a problem. In the case of the AT form factor power supply, disconnect the power wires from the motherboard and try turning on the power. The power supply fan should come on, if not, you may have a bad power switch. In the case of a ATX form factor, confirm that the power wire is connected properly to the motherboard to the proper pins, you will need your motherboard manual to verify the pins this wire connects with from the switch on the front of the case. Finally, check that the switch on the ATX power supply, on the back of the case, is in the ‘on’ position.
Now, check the Ram memory modules. Remove them and reseat them. They might have become loosened from the motherboard. You should also check that the video card is well seated into the slot on the motherboard. You can remove the card and reinstall it. If you have not found the problem, then we move on to the more difficult measures.
We should now remove the CMOS settings, one or more of them may be wrong and causing the issue. There are two ways to deal with this. The simplest is to find the jumper pins on the motherboard that discharge the power to the BIOS. You should have your motherboard manual on hand to find them. If you do not have the manual, typically you can download one from the motherboard manufacturer’s web site. The computer’s power cable must be unplugged and then you move the jumper to the discharge position. This only takes about ten seconds, then you can move the jumper back. The second method is to remove the battery from the motherboard. This is straight forward, find the battery on the motherboard, carefully remove it, wait a couple of minutes and then replace it.
The next item to check is the CPU. First, if your motherboard has jumpers to set the clock multiplier and FSB, check these settings in your manual against the jumpers on the motherboard. Now, carefully remove the CPU and examine if for browned areas or obvious signs of heat damage, then return it to the socket.
Okay. We have checked all the easiest of items. The next step will require some more creative diagnostics. At this point, we must confirm that the memory, CPU and video card are working. To do this, you will need another computer.You need to switch out each of these items to the other computer to confirm that it works. Try the video card and ram memory first. When you switch out the CPU, you will need to adjust the jumpers on the second computer’s motherboard to match the settings required for your CPU. If as a matter of course, the second computer will not boot with one of your components, you probably have found your problem part. Try using the good part from the second computer in the first computer to see if it will run with this component.
Finally, if you have followed all the above measures, you have verified the CPU, the video card and ram will work in another computer, you can safely believe that the motherboard is the problem. You will need to remove the motherboard and replace it.
We plunged right in and solved possibly the most difficult diagnostic issue you may ever confront. We will address other issues in upcoming editions of this Newsletter. If you found some of the terminology difficult to understand, please let me know by Email. I want everyone to stay with us as we explore other issues in upcoming editions of this Newsletter.
Have fun
Bob Wright
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