Bios Hot Swap Tutorial

edited February 2009 in Science & Tech
So you trashed your bios and you have heard about this Hot Swapping thing. Well what exactly is Hot Swapping?

Well it is basically taking the bios from a non-booting system where the bios flash went bad or was the wrong version and reflashing it on a working system that has a compatible chip. The procedure itself is simple but the problems that can arise are catastrophic. I will try and explain the procedure as well as what to be careful of so you don't end up ruining two bios chips and then having two systems down.

When you get ready for the Hot Swap procedure you will be required to have another working system that has the same or compatible bios chip. The motherboards do not have to be the exact same model, as you will have to force the flash when you try and update the chip that has the wrong or corrupted flash on it. A for instance is a motherboard that has a PMC 49FL004T chip on it and the flash went bad you could Hot Swap on a motherboard that has a SST 49LF040(A).

If you should have any questions as to the compatibility of one chip to another please refer to my Bios Chip Compatibilty Page and if the two different chips are in the same exact colored row then they are compatible.

DISCLAIMER: BY ATTEMPTING TO RECOVER YOUR BIOS USING THE HOT SWAP METHOD YOU AND YOU ALONE BURDEN THE RESPONSIBILITY OF ANY HARM OR PROBLEMS THAT MAY ARISE FROM SUCH ACTION. SHORT-MEDIA.COM OR MYSELF CANNOT BE HELD RESPONSIBLE AS WE ARE NOT THE ONES PERFORMING THE HOT SWAP OR DO WE HAVE CONTROL AS TO HOW THE PROCEDURE IS PERFORMED.

Tools List:

In the following image you will see some tools that are used to remove bios chips from the socket and one homemade version that works well and the cost is very small.

On the left is a DIP chip extractor that is used to remove the long rectangle chips that are on the older motherboards.

In the center you see a PLCC chip extractor that is used to remove the small rectangle chips in newer motherboards.

On the right you see a PLCC paper clip chip extractor. Yeah that is the cheap version and it works well if you're careful.

[IMG]http://users.keyway.net/~tmod700/Bios Chip Extractors.jpg[/IMG]

To make the paper clip extractor just take a regular paper clip and straighten it out so you leave the curled end. Now take some pliers and bend slightly over 90 degrees on the straight end. You should now have a little hook at one end and the other end a little handle to hang on to.

Anti-Static Wrist Strap:

One thing that I do need to mention is that bios chips or any electronic chip for that matter is very sensitive to static. So we really need to dissipate the static before and during the Hot Swap process. One way you can do this is make sure that you ground yourself to the case or wear a anti-static wrist strap as shown in the image below. Just strap the one end around your wrist and clip the other end to the case and you will be protected from any stray electrical currents.

[IMG]http://users.keyway.net/~tmod700/wrist strap.jpg[/IMG]

Performing The Hot Swap.


Ok enough of the intro let's get this thing repaired.

With two systems available (The one system with the bad flash) & (The one that you are going to use to reflash the bad flashed chip). With the power disconnected from the bad flash system take whatever bios chip extraction tool you have and carefully remove the chip from the socket. Please use the image below as a reference as to where the points are to remove the chip from the socket (Shown in red). If you use the paper clip extractor just hook it under one side of the chip and lift a little and then go to the other side until the chip pops out.

Also notice the white dots on the chip and socket? The dots are there for the purpose of orientation of the chip to the socket. Get the chip in wrong and you just bought yourself another bios chip and at worst another motherboard.

[IMG]http://users.keyway.net/~tmod700/Bios Socket And Chip.jpg[/IMG]

I have heard of people using dental floss as a chip remover and I have tried it and it does work so I am including an image of that as well. The only problem is that you have to remove the chip to get the dental floss under it. For the sake of easy removal of the bios chip when it is in the system you may consider placing the dental floss underneath the chip prior to powering up of the recovery system. It will look something like the image below.

[IMG]http://users.keyway.net/~tmod700/Floss Extractor.jpg[/IMG]

When you want to remove the chip just pull the dental floss tight and carefully pull the chip out. You could also use fishing line as long as it is non-conductive.

CAUTION: Whatever method you use to remove the chip from the socket please make sure that you don't short any of the pins when you remove or install the chip. This will lead to sure death for the bios chip and possibly the motherboard.

Ok now with the bad flashed chip in hand power up the system you are going to use for the Hot Swap. I would suggest having a boot disk already made up and in the floppy drive with the correct files for the chip you want to reflash.

Once the system boots up and gets to the A: prompt just remove the bios chip CAREFULLY from the socket on the motherboard and set it aside on some anti-static surface.

Now place the chip that has the bad flash on it in the socket with the correct orientation (No mistakes here please).

Start the flash procedure and you might have to use the /F switch in Awdflash for the forcing of the flash.

Now if everything went fine the bios should be reflashed and you can power the system down.

Now remove the new flashed chip from the socket and place it back in the motherboard you removed it from in the correct orientation.

Now take the chip that you removed from the system you used for the Hot Swap and place it back in the socket in the correct orientation.

Power up both systems and make sure that they both restart without any problems.

If both systems boot up ok then consider your Hot Swap a success.

Congratulations!!! You Did It.

Comments

  • edited September 2005
    Tmod wrote:
    If you should have any questions as to the compatibility of one chip to another please refer to my Bios Savior page and if the two different chips take the same exact Bios Savior then they are compatible. There are also chip cross reference charts but the Bios Savior menu is easier.

    Where is this magical page you speak of?
  • MissilemanMissileman Orlando, Florida Icrontian
    edited September 2005
    Great Tutorial. I have just a couple of items.

    I have done this several times over the years and I find it easier to unseat the bios chip on the good board and only set it in the socket enough to make contact. This makes removal easier and quicker while the power is applied. Electrically it is fairly safe because the chip is only on low voltage momentarily to be read during the boot up.

    On this same point you might want to add a caution to make sure you are at the A:\ prompt before removing the chip and not in the flash utility. Somtimes going into the flash utility puts power on the pin used to enable flashing. If you should remove the chip while this is hot you will possibly fry both chips. Removing and inserting.
  • edited September 2005
    renzokuken wrote:
    Where is this magical page you speak of?

    Was Also looking for this Magical Page....

    NEI Have a Link to it

    TIA
  • lemonlimelemonlime Canada Member
    edited September 2005
    Great guide! you should consider submitting it to be published by SM.. more info here..
  • edited September 2005
    Where is this magical page you speak of?
    Oooops my bad.

    It is fixed now.

    Tmod
  • edited September 2005
    Missileman wrote:
    I have done this several times over the years and I find it easier to unseat the bios chip on the good board and only set it in the socket enough to make contact. This makes removal easier and quicker while the power is applied. Electrically it is fairly safe because the chip is only on low voltage momentarily to be read during the boot up.
    While I agree that it may make it easier, I feel that the person that is doing the Hot Swap may not install it far enough and have a problem with the chip popping out or a inconsistent connection and botch up the flash.

    I will however change it to read that you should remove the chip from the good board that you are using for the hot swap and place dental floss under the chip prior to booting that system up.

    That way they will have a easy way of removing the bios chip.
    Missileman wrote:
    On this same point you might want to add a caution to make sure you are at the A:\ prompt before removing the chip and not in the flash utility. Somtimes going into the flash utility puts power on the pin used to enable flashing. If you should remove the chip while this is hot you will possibly fry both chips. Removing and inserting.
    From my tutorial,
    Once the system boots up and gets to the A: prompt just remove the bios chip CAREFULLY from the socket on the motherboard and set it aside on some anti-static surface.

    Thanks for the suggestions!!

    Tmod
  • edited February 2009
    Thank you so much. I was a little nervous at first, but next time it will be a piece of cake. Dental floss worked pretty good/as well as the paper clip. BTW, thank you for helping me "unbrick" my motherboard. :)
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