Computer Assembly - How To Assemble A PC
First Boot Common Problems
If something goes wrong after any installation of hardware then first you should double-check your install and verify that you did what you meant to do.
If you noticed anything unusual when you flipped on the power switch on the power supply, which is done before you even push the power button on the front of the computer, then you may have the system panel cables incorrectly connected. This is very easy to do since they are not keyed, but I've never seen it ruin anything. One symptom of incorrectly connected system panel cables at this stage would be if the hard drive LED on the front of the computer lit. After all, there's no hard drive in the computer. But this means the wrong system panel cable is plugged into the wrong system panel connector pins for the hard drive LED.
If you push the power button on the front of the computer and absolutely nothing happens, no lights, no fans, just stone cold silence, then this can also be caused if the system panel cables are incorrectly connected. The system panel cables include connections for the power switch and the reset button. It could be other things like your power is out or the power supply is not connected to the motherboard, but I doubt it's that gross an error. Also, check the red slider switch on the back of the power supply. The switch should be visible on the power supply looking at the back of the case. Verify it is set for the right voltage for your country. It should allow two values which may be 110/220 or 115/230. A value of 110 or 115, whichever it offers, is correct for the U.S.
For any problem you encounter during the first boot, it's always worthwhile to try fixing it by clearing the CMOS. As I mentioned at the start of the Computer Assembly - First Boot page, it's possible for the BIOS parameters to be set in ways that will cause the computer not to boot, although in most cases (but perhaps not all cases) it should still exhibit signs of power, such as fans spinning, at least for a few seconds.
If the computer powers on, but shuts itself down after only a few seconds then it could be that the computer thinks the fan on the CPU cooler is not turning. If this symptom occurs with a single long beep before shutting down then for sure this is the problem (and congratulations on having at least the speaker portion of the system panel cables connected properly). This automatic shutdown is actually a safety feature built into many motherboards, usually as an option in the BIOS, since if the computer is running without a fan cooling the processor then the processor will very quickly overheat and become ruined. Many motherboards require that the CPU cooler fan be connected into a particular fan header on the motherboard, which is then checked by the BIOS on boot to verify a fan speed is recognized. If the CPU cooler fan is connected to the right header but the fan is not spinning then this is still a problem. It may also be possible, and I'm speculating here, that the BIOS could decide the fan is not spinning fast enough, or it could be that the fan is spinning but the BIOS is not detecting it for some reason. In any event, if the symptom matches then the computer is definitely unhappy that, as far as it is concerned, the fan on the CPU cooler is not spinning. If all seems well but the symptom persists then you can try a different make and model CPU cooler.
If the computer emits a beep sequence other than a single beep then something is wrong. The beep code emitted will give an idea of what the problem is. Beeps can be short or long. They can be emitted in a sequence, such as one long and two short. They can repeat after an interval. The manual for your motherboard should contain a chart describing what each beep code means. If it doesn't then call the motherboard manufacturer to find out what the beep code means. Although it's not uncommon to see different motherboards use the same beep code for at least some of the problems, there's no standard so different motherboards may use different beep codes for the same problem. Another reference for what the beep codes mean is this computer beep code page from ComputerHope.
One common cause of the faulty beep code is that the computer is not recognizing the video card. The beep code commonly used to indicate this problem is one-long-two-short. If the beep code indicates "no video card found" then try reseating the video card. You can try this several times if the problem persists. But if, after a number of tries, you still get the "no video card" found beep code then you should replace the video card. When this has happened to me, I've returned the video card and instead purchased the next more powerful video card - may as well get a little more kick for my effort. Plus, you never know if there's just some sensitivity that maybe a particular motherboard has with a particular model of video card, so changing the model takes that variable out of the equation. You may even want to go a step further and use a different make of video card, meaning use an NVIDIA-based model rather than an ATI-based model, or vice versa.
Another common cause of the faulty beep code is that the RAM is not installed properly. It may be in the wrong slots, not fully seated, or possibly bad. Try re-seating the RAM and trying the first boot procedure again. Double check the motherboard manual to make sure you are using the right memory slots. If you are using more than one stick of RAM, try using just one stick at a time in the proper slot to see if it's a bad stick of RAM. It's highly unlikely that the memory slot itself is bad, but of course you can't rule anything out until the problem is solved.
If all seems well but the BIOS header screen is displaying the wrong processor speed (a lower processor speed) for your processor then this is nothing to worry about and even normal at this point. It's just defaulting to something safe. It will run at full speed once you set the BIOS parameters in a later step. I actually mention this can occur on the Computer Assembly - First Boot page, but I get questions expressing concern about it all the time so apparently it's easy to miss.
Here is my #1 most frequently asked help question. It goes something like this. I'm having problems at the first boot step in the assembly process. When I turn on the computer, the fans spin, but there are no beeps and the monitor LED never goes to steady green. The computer just sits there with the monitor displaying a message like "No signal or cable disconnected". What could the problem be?
Try this: Try pushing the reset button.
Try this: Is the power supply up to it? You should be using a high-quality power supply with wattage that meets or exceeds the minimum power supply wattage recommended for the video card. If the power supply is not at least 500 watts then it may not be sufficient. And a computer configured with two video cards using SLI or Crossfire could easily need at least a 550-watt power supply.
Try this: Verify all the power connections that are required from the power supply to the motherboard have been made. For example, I needed to make two connections, one for a 24-pin power connector and one for a 8-pin power connector.
Try this: If clearing the CMOS did not work then try clearing it again, but this time by removing the battery from the motherboard and leaving it out for 30 minutes. When you cleared it the first time, you may have left the battery out for seconds. That's fine and the "book" says that should do it. But experience has shown that a much longer time period - 30 minutes instead of a few seconds - can make the difference. As usual, everything should be unplugged from the back when you're working inside the computer, especially the power cord in this case. After returning the battery to the motherboard, re-connecting everything in back, and then turning on the computer, see if you get a beep this time. If you do then enter the BIOS so you can load default BIOS settings.
Try this: Check the system panel cable connections. Since there is no beep, it could be they are not connected entirely correctly since the connection to the internal speaker is one of the system panel cables. The connection to the power and reset buttons are also system panel cables, so since those are working then at least some of the connections are right. Since the system panel connections are not keyed, it's easy to plug them into the wrong pins or the wrong way around on the right pins. Manuals are often not as helpful as they should be. I've never known plugging them in wrong to damage anything and I've done it plenty of times, but it can cause the computer not to boot. It's easy to accidentally unplug them, too, since they are close together and space is rather confined.
Try this: Try booting with just one memory module installed. If the problem persists and you have more than one memory module then try booting with just the other memory module. Be careful to install the single memory module in the proper memory module slot that should be used when there is only a single memory module installed.
Try this: Try re-seating the memory modules and video card. Check carefully and make sure they are inserted fully and properly into their slots. Be careful not to over tighten the slot screw holding the video card in place as this can twist it within the slot, causing an electrical misconnection. If you're using two memory modules then try using one memory module at a time. If after re-booting the problem persists then try re-seating them again.
Try this: Is the memory of high quality, and are you sure the memory is right for the motherboard? I hope you used the
Crucial Memory Selector
or followed my links to get the right RAM.
Try this: Visually inspect the processor. I know this means re-mounting the CPU cooler, but a damaged processor is one of the more likely reasons for these symptoms. Examine the pins and verify that none are missing or bent. Verify that the processor is mounted flat and flush with the socket.
Try this: Try booting without the memory modules installed. Or try booting without the video card installed. The computer should certainly give quite a nice beep sequence with either of these components missing, so if it does beep with either component removed then you know the problem is with that particular component.
Try this: It could be the motherboard is grounding to the case through one of the mounting screws. This is a common cause of this problem, but I saved it for last since it's the most hassle to verify. To check, remove the motherboard from the computer case and place it on a table. You can set it on something to ensure the table isn't scratched, such as the packing in which the motherboard came. Leave all of the first boot components (video card, RAM, and so on) installed and connect all the power and other cables just as you would if the motherboard were inside the case. The difference is the mounting screws are not inserted into the motherboard since the motherboard is not mounted in the case. See if it will boot. If it will then the problem is that the motherboard is grounding to the case through one or more of the mounting screws. It may be that the problem will clear up by simply remounting the motherboard into the computer case again. If the problem persists then you can insert small, rubber washers between the screws and motherboard on the top of the motherboard. If the problem still persists then you can insert small, rubber washers between the mounting posts and motherboard on the bottom of the motherboard.
Try this: As a last resort, take it to a local computer shop and have them check it out. This normally costs under $100. The other option is to RMA (return merchandise authorization) the bad component to the reseller for replacement. This option is not so great if you haven't managed to isolate the problem to a particular component. It's going to be very frustrating if you go to all the trouble of swapping out a component with the reseller only to discover that the problem persists once you have it all put together again. So when the local computer shop guy tells you what was wrong, please consider posting it on the My Super PC Forums if there's something overlooked here.
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