PC won't start? - A guide to troubleshooting...

[Xen]

There are a number of solutions to this problem. Unfortunately, troubleshooting this seems to be the most difficult, since there are many things which could be preventing the system from starting. Here's a list to get you started.

(NB: If your system is completely failing to give any power whatsoever, as in, "absolutely nothing is spinning up," pay special attention to the power supply and motherboard troubleshooting steps.)

It is important to remember that parts, more often than not, fail individually. Therefore, once you find a bum part, you're probably done. However, I strongly encourage you to follow all the steps of this troubleshooter, just to be on the safe side.

Before we begin, keep in mind that opening the case may void your warranty if you purchased a prebuilt system. You should only do this if you're comfortable with the idea of opening your computer and poking around in there. If the idea scares you, don't do it. If you feel like you have no idea what's going on, but want to learn, go ahead, but, again, be aware that you're voiding any warranty that came with the computer as a whole.

Most importantly, however, I must disclaim any responsibility for whatever happens to your computer. This is a detailed guide that had input from many in the Orbiting HQ, but if you screw up, I, nor anyone else at Ars Technica, can be held responsible. You are the sole person on the face of our mother Earth who can be responsible for doing anything, be it good or bad, to your computer.

1. Make sure everything is plugged in correctly

This is a very common mistake. Usually it is the motherboard or the boot drive. Some motherboards have two connectors: the really big 20-pin one, and a small 4-pin square one. If your motherboard does not have both of these, it will only have the 20-pin. Make sure that is secured into place. If that's ok, move on to all the hard drive cables: 4-pin power and 40-pin data. The data ribbon should trace to the motherboard. Also, the red side of the ribbon should be on both pins 1 or both pins 40; it cannot be turned around.

A general review of all the wires should be performed. Where do they start and end? Do the connections make sense? Despite what most people think, the inside of a computer is really common sense; everything fits only in one slot/hole/whatever, and all the wires go from point A to point B, with both points relating to each other.

2. Clear the CMOS

This is often the solution, and it's frustrating because it's incredibly simple. All you have to do is find out from the motherboard manual where the CMOS jumper is. Make sure the system has no source of power (meaning the power supply is unplugged and the battery is removed). Then, move the CMOS jumper over the pins that clear it. After a few moments, put the jumper back, plug the power and battery back in, and try it.

If it works, you're done! Congratulations on being extremely lucky! Karma will probably come around later and bite you in the ass.

If not, continue on. You may have a long road in front of you.

3. Strip the system down

The first thing you should do is remove the system from the case, place it on a non-conductive surface, and disconnect all components from the motherboard with these exceptions:

• CPU (and heatsink/fan)
  
• A single stick of memory
  
• Video
  
• Power supply
  
• Power button
  

This means no drives, no peripherals, no extra ports, nothing. This tests two problems at once. They are the possibility of some peripheral preventing the system from powering up and the possibility of the motherboard shorting onto the case somehow (aka, a standoff that should not be there).

To do a quick elimination (only if the system is completely failing to give any power at all), find where the power button connects and short those two pins for a moment with anything conductive that you have on hand. A screwdriver, knife, coin, or anything metal will work. If the system spins up, you need a new power button. (If your system was already spinning up, you can skip this step.)

If the system fails to power up outside the case, here are two things you need to do. First, do a visual inspection of all the capacitors on the motherboard. These are the little battery-looking things. What you'll be looking for is any fluid leaking out of the top or bottom, any "gook" anywhere on them, or if they are bulging out the top or sides.

While you're poking around for bad capacitors, take a look at the ATX power connector; make sure it doesn't have any scorch marks or look melted. If anything shows any of these characteristics, your motherboard is almost definitely your problem. If they all look ok, test repeatedly, with each stick of memory individually in each slot (this means nine tests for three sticks of memory on a board with three slots!).

If the system eventually powers up, you've found good memory ? probably your only problem ? and you're probably done. Put the stripped-down version back into the case and secure it. If it powers up again, skip to step 9.

If not, you need to remove it again and investigate the setup of your motherboard standoffs and make sure nothing is touching the motherboard where it should not be touched. After this is done and all is well with the basics inside the case, skip to step 9.

If it fails to power up with any memory configuration out of the case, we know it must be either the CPU, the memory, the video, the motherboard, or the power supply, or any combination thereof.

With this in mind, and our system still out of the case, we continue.

------------------------------On to the CPU----------------------------------4. Does your CPU work?

There is only one good, reliable way to test this: drop your CPU into a known good and working system. Use a friend's, a neighbor's, roommate's, hallmate's, coworker's, or whomever happens to have a system that will take your CPU.

If your CPU allows this known good system to power up, you know that it is good, and it is not the cause of your problems.

If not, you'll need a new one. As above, it's likely that this is your only problem, and once you get it replaced, you'll be good to go.

Note that I did not say to try another (known good and working) motherboard. The reason for this is that there are too many other variables at play: does the RAM work? does the video work? is the power supply work? These questions will be addressed lat5. Does your memory work?

There are two (probably equally reliable) ways to test this, although one is riskier than the other.

The first is to take your memory and pop it into a working test system (perhaps the same one you used for the CPU) and, again, see if that system powers up.

If it does, we know the memory is good. For good measure, test all of your sticks in all possible combination, just to be sure that it's not a pair of sticks not playing nicely together.

If the good system fails to power up, you have bad memory and need to replace it.

The other (and riskier) way to test memory is to take known good and working memory and put it into your motherboard. This is riskier because the possibility exists that it is the motherboard that is bad. It is not unheard of for bad motherboards to kill good sticks of memory. Take this route only if you have no other test system.

If the system powers, you had bad memory. If it does not, the problem is either your motherboard, your video, or your power supp6. Does your motherboard work?

This is extraordinarily simple to test: get another motherboard from somewhere, put together the basic system (as described in step 3), and see if it boots.

Again, if the system powers, you had a bad motherboard. If it does not, the problem is either your video or your power supp7. Does your video card work?

This can be tested in two ways, just like the memory: using the test computer, and a different card. However, this time, the risk of burning a good part on a bad board does not exist, as we have already tried the board. You must know, however, that if you are testing a good video card with a bad power supply, and that good card plugs directly into the power supply, you may end up a brand-new, very flat paperweight.

Something that makes this test easier is onboard video. If your motherboard has it, and it works, but no known good video cards work, you probably have a bad AGP slot. Take a gander in there for bent pi8. Does your power supply work?

This is simplest of all; at this point, you've ruled out everything except it, so grab a good one and plug it in.

If the system still does not work at this point, it's time for you to post a help thread describing the problem and what you've done so f9. Time to start rebuilding the system.

Congratulations on having gotten this far! If you've skipped to this step from step 3, your problem will probably be encountered here. For those of you that got here the hard way, this is probably not of consequence to you, but I encourage you to follow these steps, anyway.

At this point, you have a good CPU, motherboard, memory, video, and power supply. You also have a good case that is not shorting the motherboard. So, the last thing left to test is the rest of the peripherals and PCI slots.

To do this, start installing things and/or plugging things in one at a time! This way, if there is a bad peripheral (or slot), you will notice it immediately, because all of a sudden your working system won't work after having plugged in that next item. Check the PCI slot for bent pins to make sure it isn't actually a bad card.

This is probably the end of your troubles, once you find that bad peripheral or slot.

If you skipped to this step from step 3, and have installed all of your original peripherals, and still have no problem, then... something was up, but is no longer. Consider yourself.

At this point, you should be done. If you have a buggy system and your problem was not solved by this guide, post something in the OpenForum along with a description of what you have done to troubleshoot it.

Source: Arstechnica

---I might of went alittle too far..Not sur:o :o ---

[KC]

Very good guide.

[Advance]

One problem is, if their computer isn't working, they probally can't read this ;)

Good job though.

[insanekiwi]

good guide. people should print this out and stick it next to their monitor :)

[Hypoxiaicon]

Not a bad guide at all (Y)

[Vignesh]

Nice guide, thanks!

[j.r.l.]

Goog guide. 4/5 because it;s obviously not coming from you

[zedaxax]

good guide

also if your boot files are corrupt and xp wont startup - this has saved my life on several occasions

Start your PC with the 6 XP install disks. Get them here

http://www.microsoft.com/downloads/results...&DisplayLang=en

start your pc witht the first floppy in - follow instructions

Select Repair ? option.

On the startup setup screen when your PC brand logo appears, press "R" for recovery console. it should give you the prompt.

Now type "chkdsk /r" (space after Chkdsk without " ")and enter leave it to finish. Now restart by typing "exit" and press enter. It should work.

If it doesnt help - do steps 1-3 but on step 4 type "chkdsk /p" and enter. If it finishes. type "fixboot X:" (X being the drive letter windows is installed on, it's usually C, but sometimes it can be a virtual drive like E). Next press enter.

Finally type exit to restart.

if non of the above work (which i doubt)

Go to the DOS prompt. Type chkdsk /p /r + enter. When check disk is finished, type fixmbr + enter.

It should work.

[RightyFX]

wow thank you man, i appreciate this

great guide

:yes: