Recently we've been getting a lot of questions from people who basically have the same problem - they've assembled a PC but it won't start up correctly!

There is a standard troubleshooting procedure for that scenario which everyone should follow, and I'll describe it to you in a moment. But first let me address a few common issues for people whose older PC won't start any more:

* Does it 'hang' when it's loading Windows or when it reaches the desktop?

If so your problem is most likely a software one and NOT a hardware problem. You should, of course, check that all the cooling fans are working (especially the ones on the processor and the video card) in case overheating is a problem. If you have two or more sticks of RAM which are from different manufacturers you could try using them one at a time in case a RAM mismatch is causing the problem. But other than that the only real way to see if it's a software or a hardware problem is to try running it with a fresh, clean installation of Windows.

Go buy a second hard drive. Extra storage space is always worth having and they're quite inexpensive. Swap your current drive out, put the new one in, and load Windows onto it. If all runs fine you know for certain that the problem is in your original Windows installation. If not you've got a second hard drive to use once you track down the hardware problem and fix it!

* Have you recently changed internal hardware items?

Added RAM? Changed a display card? Added or changed a drive? Whatever the internal change has been, if the machine won't start afterwards you've got clues to where the problem lies. Remove the recently added device or component and try again. If it still won't start have a good look inside to ensure you haven't dislodged or damaged some other component while you were working in there. Make sure everything is firmly in place.

* Have you reset CMOS?

No, setting it to default in BIOS Setup isn't good enough. When you make changes to the hardware of a PC you need to physically reset the CMOS memory, either by 'shorting' a jumper on the mainboard or by removing the CMOS battery and waiting several minutes at least before replacing it. A vast number of instances where machines won't start up are simply the result of changes made without resetting CMOS afterwards.

* Did you ensure that the power was switched off at the mains before working inside the PC?

Shutting down Windows isn't good enough. Modern ATX motherboards still have power running through them after Windows has been shut down! You must either switch off at the wall outlet or remove the power cord before opening it up to perform internal work. Damage to components can ensue if you make hardware changes when the motherboard is still receiving power.

Now, to the original point of this post.

* Does your newly assembled PC refuse to POST?

Even without a hard drive fitted, your machine should run the Power On Self Test. If it doesn't, then it is either incorrectly assembled or it contains a faulty component. You should be getting the memory check, the device detection information, and perhaps an 'Operating System not found" message.

Unfortunately, although PCs are quite easy to assemble, putting the whole thing together before trying it to see if it works is far from the ideal approach. If the entire PC is fully assembled, tracking down the reason for the failure can become a nightmare. The 'bare bones' approach is far better when assembling, and far better when troubleshooting. If your system is already fully assembled, go back several steps and try again.

The 'bare bones' PC contains only the following components:

- Motherboard
- Processor
- Processor heatsink/fan unit, connected to power
- A video card if there is no onboard video available
- One RAM module (unless the RAM is of a type which requires installing in pairs. 'Dual channel' RAM is NOT such a type!)
- The front panel connectors for Power Switch, Power LED and case speaker attached to the motherboard
- The ATX connector connected and supplying power to the motherboard. - The P4 power connector attached also if required. A molex connector attached to the display card if required.

That's it. Attach monitor and keyboard and see if it'll POST. Reset CMOS and try again if it doesn't. If you are building a new system stop at this point and try it out. If you're troubleshooting a fully assembled PC strip it back to this point and try!

If the PC won't POST in this configuration you need to determine why before proceeding:

*check power switch and LED connectors. If they are reversed the system won't start
* check that the processor is correctly fitted
* try a different RAM module
* ensure that the display card is correcxtly seated.
* get a technician to check it over if you can't locate the cause

Once the 'bare bones' system is operational, add other components one by one. Try starting the machine after every addition to check that it will still POST. This is the ONLY procedure by which you can adequately and effectively troubleshoot where a hardware problem lies.

'Other components' includes additional RAM modules, add in cards, drives, etc etc etc....

If your are troubleshooting a system which has already had Windows installed to a hard drive, add that drive last so that the system doesn't continually try to boot into Windows.

If you strike problems and need to post a new thread about your problem, include the following information:

* Identification details (make and model) of all components
* Full details of any onscreen error messages
* Full description of any BIOS 'beep' codes emitted through the internal speaker.

Cheers, and good luck with it.

Sayi commented: very useful article +0
Muralidharan.E commented: Usefull article +0

I have built a system not that long back and not any problems with it at all, in fact it's far more stable than any i previously had ever bought from any shop. I have recondition pc's in the past and this new one was set to be a challenge.. and came up trumps. Just to say never lose hope in building a first machine... if thwey work trouble free after your labours then it's a real buzz to you ego. Plus being your own technical support beats paying a £1 a min on any premium line...

Simple basics to be aware of

1) Static : Most components for computers can be easily damaged from static so be extremely careful, earth yourself by ensuring that your pc is connected to the mains but switched off at source (at the wall) this will provide a static drain for you. and ensure that you freqently earth your body to the chassis by touching the chassis with your free hand. Better still obtain a static wrist strap with a clip lead and connect that to the chassis, this will free both hands and avoid static damage too.

2) Don't drop components or manhandle in any way... you payed good money for them, so treat them like gold.

3) Read all instructions provided with components prior to installing them. Ideally draw up a basic list of components and make sure you have puchased all of them before proceeding to build the pc, including leads and outside peripherals.

4) Work preferably in the daytime for maximum light in a well lit place... by a windows good, also you'll be more awake to concentrate with the job at hand earlier in the day. Keep yourself organised - methodical and this will make the project more a pleasure.

5) Careful when installing the motherboard using the plastic lugs to avoid shorting the motherboard to the chassis in the case. Ideally use a rubber mat and lay motherboard on that on a flat table surface, then install processor and fan, not forgetting thermal paste. between underside of cooling plate and top of the processor itself, this will draw excess processor heat away from processor. This will aid in preventing processor damage another major pc hiccup leading to invalid page fault errors or other wierd messages appearing.
Good idea to install ram sticks (Memory at this point!)... Once this is done the dodgy bits over with. Then install motherboard and lugs into pc cpu tower, midi tower whatever case.

6) Graphics cards, sound cards etc... handle carefully install as per instructions provided. with windows XP you will get reports that your hardware doesn't have a xp certificate - licence... continue with installation.. it's just XP trying to be awkward with licencing regulations.. usually cards will work with no problems.

7) ensure cpu cases have adequate cooling depending on spec of machine as an overheated machine will prove very unpredictable or unreliable..

8) Usb 2.0 may present problems with Windows 98 se, though ok with XP

Hope this helps in building you new home pc project

Have fun and hopefully a working pc to display to your friends, and able to say ... hey i built that one ....waheey lol

My own ‘Golden rules of static’:

  • Never work on the insides of your PC in a carpeted room.
  • Never work on the insides of your PC whilst wearing clothing made of synthetic materials such as nylon or the like.
  • Always ‘ground’ your body by touching a bare metal portion of the case chassis before touching components.
  • Always handle components by their edges. Do not touch onboard chips or their connectors.
  • Never touch the metal card connectors.

I personally don't use an anti-static wrist-strap, and don't think that using one will be much help if the points above are neglected.

Im copying one of my posts in here, as I think it is good advice to avoid Electro Stactic Discharges.

If you work on a PC, and that PC has a three pin plug, (where one is earth), and a power switch to cut power to the system - you should only cut the power via the switch, and leave the plug in as it provides earth. Then as you work on the system, ensure that you make regular physical contact with the (unpainted) metal frame, either by grabbing it for a few seconds, or using, as suggested, an ESD wristband.

For some more info

Also try and ensure someone else is around incase you have a problem.

Be safe...

Another thing to point out: You can get special ESD mats which will help control the discharge. Also you should keep all components in their special protective bags until you really need them.

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