While helping Reginald diagnose his PC today I realized there was a need to some information on PC diagnostic techniques and so I am adding this post of dealing with a PC that just won't boot at all. (STEP BY STEP PROCEDURES)
By "won't boot at all" I am referring to a PC that does nothing when you power up.
First check the power, do you have a power LED
If not check the power cable, is it secure, don't forget to check the wall outlet, is there power at the outlet, is the power cable plugged into the wall and the PC (Trace the cable), make sure both eds are the same cable!
Make sure the power switch on the back, the one at the power supply (most power supplies have them, some PCs no not) is switched ON!
Are the Fans Turning, or is there any indication of power getting to the PC
Is there evidence of power to the motherboard, leds lit, CPU fan turning etc.
POST CODE beeps? Do you here any? A healhty PC will have one short beep at the end of the POST sequence.
2. Open it up NOTE: Be sure and observe all safety precautions!
Prepare a good work area the kitchen table will do fine. You will need access to a power outlet and a computer monitor and keyboard.
Remove the case cover or access panel and orient the computer so you can easily access the motherboard and other components.
Plug the PC in, if it has a power switch on the power supply make sure it is ON and press the power button on the front panel.
Observe the power, are LED's lit, are fans turning etc? If you have power proceed to step 4, otherwise you will need to test your power supply (not an easy task without proper equipment, you might just want to replace it with a known GOOD power supply and see if this solves the problem.
4. Do you get a POST code?
If you are fortunate enough to get an audible POST CODE (a series of beeps) then this is a plus.
Refer to the BIOS manufacturer manual for the proper meaning of each code.
A single short beep is the sign of a normal POST finish - OK READY
If you get a ONE SHORT BEEP you should suspect that PC is booting and the possible culprit is a video problem (not always but usually)
If you get any other series of beeps consulting the post codes for your particular BIOS could lead you straight to the defective component.
If you cannot rely on POST CODE then proceed to step 5.
5. Disconnect all unnecessary items INCLUDING POWER FROM WALL !
START BY DISCONNECTING ALL POWER
Remove all cards from the mother board (modem, network, sound, RAM etc.), this includes RAM - Don't take short cuts, you will probably only end up having to start over.
Disconnect the date cables from your Hard Drives, Floppy, CD Rom, DVD etc at the motherboard. The goal is to have only the mother board and internal power supply cables connected (DON'T disconnect the front panel cables, however DO check that they are connected properly)
Check you manual and insert only the minimum RAM needed to boot your PC. Some motherboards use one stick and some motherboards require 2 sticks, again refer to your manual for the proper type RAM and slot locations to be filled. REMEMBER: USE THE MINIMUM REQUIRED RAM.
If your motherboard has built in video you are ready, otherwise re-insert the video card making sure it is inserted into the correct slot and is inserted correctly.
Connect a monitor to the video connector, and reconnect the power cord to the power supply.
make sure the monitor's power cable is connected and has power to it also.
Switch the power on at the back of the PC (on the power supply) press the power button on the front of the PC and turn on the monitor.
Is there an indication of power, LED's on and fans turning? If so you should expect to see POST information or a splash screen on your monitor.
If your PC booted up & you see information on the screen SKIP TO STEP 6
If the monitor still displays nothing, this article assumes you have made sure you are using a working monitor in good condition, then the suspects could be any of the following...
CPU could be defective
RAM could be defective
Power supply could be weak or defective
Video Card (if you don't have built in video) could be defective
For each of these components you need to either swap them out with known good components or test them by placing them in another PC. Do this one component at a time!
If all components are good then you more than likely have a dead motherboard.
6. Start adding back the other components.
DISCONNECT ALL POWER !
Add back each of the components one at a time starting with any other RAM that you have and ending with the drives. I repeat, do the RAM first and the drives last!
With RAM be sure and add it back to the correct slot and in the correct configuration as indicated by your motherboard's manual.
Between each additional piece of equipment added RAM, a card, a drive, etc reconnect the power and turn the computer on and observe that it still boots correctly. If at any point the PC does not boot then you suspect that component is either defective or it is in conflict with other components in the system. Leave it out and continue reinstalling the other components, testing and following safe practice procedures between each until all components have been reinstalled EXCEPT the HARD DRIVES.
Now on to the hard Drives - We saved doing these for last to take into account some of you may have OS's (operating system) already installed and my have been diagnosing a used rather than new built computer.
Connect each HDD (Hard Drive) one at a time, as we did with the other components, saving any HDD that might contain the OS for last.
Boot the machine and observe its functionality, if there is a problem with the machine not operating properly after the OS boots up then it is more than likely a software issue and not hardware. Unfortunately driver conflicts and other software issues are beyond the scope of this articlea and will have to be addressed separately.
At this point, excluding any software issues you should have a functioning machine and should have discovered the faulty component and either replaced or omitted it from your hardware configuration.
I hope this article is useful to those of you who are trying to diagnose hardware problems on your own.
The purpose of this article is to teach step by step LOGICAL diagnostic practices for discovering hardware issues with your equipment and while not all inclusive should supply a well grounded basic technique for diagnosing hardware issues in a dead PD.
I have written this article to help computer owners who wish to try the do-it-yourself approach BUT in no way do I encourage attempting self repair on your computers. As such, I can not, nor will not be held liable for the use or misuse of any information contained in this article and strongly advise you call a professional service technician.
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