Sunday, August 26, 2012

Computer Troubleshooting–Computer Will Not Pass BIOS

This a continuation of the previous blog post on a computer that will not turn on:  For this post I am going to focus on a computer that can turn on, but does not pass BOIS, usually indicated by a beep.  The BOIS is the initial booting of a computer – the part where you may see lots of technical information on the screen, although some computer manufactures hide this behind a fancy loading screen instead.

  1. The first thing to do with a computer that does not pass BOIS is to check for any error messages on the screen or if nothing on the screen is present, listen for any Beep codes from the computers speaker (this is not the speaker system that is attached to your computer, instead it is an internal speaker that should be attached to the motherboard for the main purpose of beep codes).  One Beep usually means the computer has safely passed BOIS and the computer has been started.  Multiple Beeps or continues beeps usually indicate a problem.  You will have to consult your computer manufacture or motherboard manufacture to determine what the beep codes mean.
  2. If you hear beep codes, you can determine what the beep codes mean and start trouble shooting from there.  For example if the beep code indicates something is wrong with the RAM, double check and make sure all the RAM is properly seated (all the way down).  If that doesn’t solve the problem then you can pull all the RAM out and place just one stick in the first slot – of course if you only have one stick this will not work and you will need to get another stick to test with.
  3. If you do not hear any beep codes, it is possible the computer has not booted far enough along for it to produce any beep codes; however, it is also possible that your computer does not have an internal speaker or that the internal speaker does not work.  If your computer normally makes a beep when you first start it up then your computer most likely has an internal speaker, which helps greatly in troubleshooting BOIS problems.  If your computer will not beep then it is possible the motherboard is bad; it is also possible the power supply is not supplying the correct voltages, power supply testers are fairly cheap and is a good way to determine if your power supply is at fault.
  4. Reset the CMOS/BIOS.  This is usually done on the computers motherboard by switching the jumpers or on some of the better motherboards through an actual button.  You will need to check your computers manual for specific instructions on how to reset the CMOS/BIOS since methods and locations of jumpers and buttons vary wildly!
  5. Try removing and reseating all the RAM in your computer (unless of course you already tried this in step 2).  Not sure why but this seems to fix a lot of the problems with computers not booting.  You can also try plugging in just one RAM stick and see if the computer will boot, do this with all your RAM sticks to make sure they are all good.
  6. Similar to my last post on troubleshooting a computer that will not boot period, unplug the computer and if you have a laptop, pull the battery out as well, and let it sit for a couple minutes to let all the power drain out.  Then plug it back in and see if it will boot.  If that does not help you can try pulling out the little coin battery as well and repeat the process.
  7. If that does not help unplug everything from the computer, including the mouse and keyboard (unless you have a laptop of course).  And try powering up the computer; if that helps try plugging the devices back in and see if the problem returns; if it does than one of your devices is most likely causing the trouble and you will have to plug them back in one by one to determine the cause.
  8. If that did not work, then try the same thing with the inside of the computer!  Unplug/remove all the components – Hard drives, CD/DVD drives, RAM, Video and PCI cards.  If that still does not work you can try removing the CPU as well – just make sure you leave the little internal speaker connected so you can listen for beep codes.  Naturally at this point the computer will not boot, what you are looking for is error codes from the motherboard to help determine if the motherboard or an actual component, such as a video card, is at fault for the problems.
  9. If your computer still does not boot it is most likely the fault of the motherboard and will probably need to be replaced.

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