Pull CMOS with Power On???

[DaveR]

I have never pulled an IC with power on. Now I see a whole bunch of posts about this resolving a bad cmos flash situation.

I have a Soyo with a bad flash, so nothing will boot. People say that you need to just get a good cmos, remove the bad cmos and hold the good chip on the socket so that a dos floppy will boot. Then they say to take the good chip off (with power still on) and install the bad chip. At that point you can try to reflash the bad one.

Anyone try to play with the flash cmos under power?

It sure does not seem safe to me! I have a new chip coming, but would sure like to "fix" the bad one as a backup!

Sure would be worth a few $$$ for MoBo's to have a ROM...enabled by jumper...that would allow you to boot a floppy, remove jumper, and then reflash cmos!

 

[interchange]

That actually could be feasible. Pulling the BIOS chip couldn't really hurt it. It could harm the rest of your system if, for some reason, the motherboard wanted to access your BIOS chip and it wasn't there. But there would just be an open circuit, which probably couldn't cause any undesired effects that would be physically damaging to your hardware. Putting a chip in is a little different, because there might be some sort of initialization necessary for the chip to work properly. In worst case, this could cause a short and fry something. That seems a little unlikely to me, so it may be worth a try so long as you are careful enough never to short any leads together when removing and inserting the chips (could be a trick). This, of course, says nothing about whether or not it would work; it only suggest that it may be safe to try.

 

[whatavalue]

I've had a problem similar to yours. I tryed to reflash my cmos, but deleted it somehow. I then tryed to make a copy of another cmos from another one of my computers, but also messed up that one. The screens on both of them went black like the built-in video cards on them were missing. I've read somewhere that all you have to do is find a old unaccelerated (not sure what that means) ISA video card, put it in and disconnect everything else. I've done it with an old pci video card that I had and it worked perfectly. Just make sure the disk is inside when it starts up. Also remember the keys that need to be pressed because sometimes you still won't get to see anything on your monitor until after it has been re-flashed correctly. This little trick saved me from sending the chips back to the maker to have it re-flashed. Hope this helps.

 

[Jerboy]

<< I've had a problem similar to yours. I tryed to reflash my cmos, but deleted it somehow. I then tryed to make a copy of another cmos from another one of my computers, but also messed up that one. The screens on both of them went black like the built-in video cards on them were missing. I've read somewhere that all you have to do is find a old unaccelerated (not sure what that means) ISA video card, put it in and disconnect everything else. I've done it with an old pci video card that I had and it worked perfectly. Just make sure the disk is inside when it starts up. Also remember the keys that need to be pressed because sometimes you still won't get to see anything on your monitor until after it has been re-flashed correctly. This little trick saved me from sending the chips back to the maker to have it re-flashed. Hope this helps. >>




You use an EEPROM writer to do this properly

 

[DaveR]

Just a few comments about the replys...

1. I was actually concerned that pulling a good cmos under power would hurt the good chip, and not the rest of the MoBo. I agree that the trick would be in putting the "bad" one in under power.

2. The trick with the video is correct...IF the boot block is still in the bios. In that case, you do not even have to get an ISA video.
All you need to do is have an autoexec.bat file on the floppy that starts the flash...like awdflash 6ba42ba3.bin

It will not work in my case as there is nothing in the bios so I can not even boot the floppy.

3. A Prom burner is what I wanted to do but the one at work is a Data I/O and does not quite go up to a 29F002 chip! They are no longer in business so it is not likely it will get upgraded. I do have a friend at Intel so perhaps he can flash it.

Thanks all.

 

[DHL]

The high tech ppl here might be able to enlight me

1) Would it be safer if I pull out the bios chip when the machine is under suspend-to-ram, or any other suspend mode?

2) Would bios shadowing help to reduce the no of access of the bios chip?

TIA

DHL

 

[Demon-Xanth]

My $0.02. I'm against pulling ANY IC under power. I'd just ask the manufacturer about getting a new BIOS IC and plugging that one in. Though many are soldered on and cannot be removed without desoldering the old one (typically the hardest part of IC swapping). An erased BIOS can be reprogrammed with an EEPROM writer or flash IC writer, however one that is electrically destroyed wouldn't even make a good keychain.

 

[DaveR]

<< My $0.02. I'm against pulling ANY IC under power. I'd just ask the manufacturer about getting a new BIOS IC and plugging that one in. Though many are soldered on and cannot be removed without desoldering the old one (typically the hardest part of IC swapping). An erased BIOS can be reprogrammed with an EEPROM writer or flash IC writer, however one that is electrically destroyed wouldn't even make a good keychain. >>



Yes, my new chip is "in the mail" so the MoBo will be up in a day or so. I have a friend with a burner...just have to wait for him to come back from a business trip. Now I can at least have the bad one programmed as a spare! This will assure me that this will never happen again.

 

[XeonTux]

Is something like this ever necessary on Intel boards that have the recovery jumper? I mean, can you fsck it up that bad where the recovery jumper cannot save you?

 

[DaveR]

I am not sure what the recovery jumper is. But, if it accesses a different chip than the cmos for an "emergency boot of a:" then the Intel should be OK!

 

[Shalmanese]

I used to work part time in a computer shop that had a case of a badly flashed ROM. What they did was put the good one in and set the ACPI to suspend in 10 minutes and then, whent he computer suspended, they pulled out the good ROM and put in the bad one and flashed it.

 

[stevewm]

I've swaped BIOS chips on my two Asus P5A boards before with no ill effects. The one I pulled the chip from was running DOS at the time. Once the computer is booted the BIOS is copied into system memory and the BIOS EPROM is not accessed anymore.

 

[DaveR]

<< I've swaped BIOS chips on my two Asus P5A boards before with no ill effects. The one I pulled the chip from was running DOS at the time. Once the computer is booted the BIOS is copied into system memory and the BIOS EPROM is not accessed anymore. >>




This one is a SoYo 6ba+iv and the cmos is under a few pci slots! I would have to take the sound card and nic out. I just do not want to kill the good cmos by pulling it under power. My thought, if I did try it, was to power down with boot floppy in drive. Remove good cmos then hold it against socket and power up and boot. At that point the chip can just be removed as it is just being held against the socket.

As I said I am just afriad of killing the good one!

 

[Demon-Xanth]

One option would be lifting the chip select pins of the BIOS chips, inserting a switch, then putting them in paralell. So basically the switch would swap between which IC is selected (remember to pull up/down appropriately) then boot to the good one, switch, flash the bad, then remove the mod.

 

[stevewm]

<< power down with boot floppy in drive. Remove good cmos then hold it against socket and power up and boot. At that point the chip can just be removed as it is just being held against the socket. >>




This is exactlly what I did. Pull the chip out slowly to avoid bending the pins. And make sure the dimple on the side of the chip lines up with the dimple on the socket. I also recommend you remove everything but floppy, video, and keyboard from the motherboard while doing the flash.


If you don't want to do any of this most mobo makers will sell you a new BIOS chip with the lastest version for $20-$30.

 

[DaveR]

Actually, I have a good one already...I now want to "fix" the bad one...I just do not want to kill the good one and now have 2 bad ones!




<<

<< power down with boot floppy in drive. Remove good cmos then hold it against socket and power up and boot. At that point the chip can just be removed as it is just being held against the socket. >>




This is exactlly what I did. Pull the chip out slowly to avoid bending the pins. And make sure the dimple on the side of the chip lines up with the dimple on the socket. I also recommend you remove everything but floppy, video, and keyboard from the motherboard while doing the flash.


If you don't want to do any of this most mobo makers will sell you a new BIOS chip with the lastest version for $20-$30. >>

 

[DaveR]

<< One option would be lifting the chip select pins of the BIOS chips, inserting a switch, then putting them in paralell. So basically the switch would swap between which IC is selected (remember to pull up/down appropriately) then boot to the good one, switch, flash the bad, then remove the mod. >>



Hey, that may be a great idea. I can see if there is a 29f002 pin-out on the web, and look for the chip select!

I could get 2 32 pin sockets, and a 32 pin plug, and wire them in parallel with a toggle!...May work! Need to see levels to see if I need pullup or down.

 

[DaveR]

I did manage to pull up a 29f002 datasheet online. Did a google search. Did not actually see a cs line. I wonder if just switching VCC would be good enough?






<<

<< One option would be lifting the chip select pins of the BIOS chips, inserting a switch, then putting them in paralell. So basically the switch would swap between which IC is selected (remember to pull up/down appropriately) then boot to the good one, switch, flash the bad, then remove the mod. >>



Hey, that may be a great idea. I can see if there is a 29f002 pin-out on the web, and look for the chip select!

I could get 2 32 pin sockets, and a 32 pin plug, and wire them in parallel with a toggle!...May work! Need to see levels to see if I need pullup or down. >>

 

[Demon-Xanth]

Pin 22: CE (chip enable)
Active low (pull down to use IC, pull up to put it in standby)

 

[DaveR]

<< Pin 22: CE (chip enable)
Active low (pull down to use IC, pull up to put it in standby) >>



Great...I did not even see the CE!

 

[divide by zero]

Been done. Awesome stuff. Called BIOS Savior. Available at mwave:

Bios Savior

 

[RagManX]

I've never done it, but you might want to ask over at the hardforums. Many of the people there are likely to screw around with BIOS stuff, and I'm sure a few have messed them up and had to do what you are asking about. I know I've read of people doing this with no harm, but I can't point you to a specific link about it, which is why I suggest trying at the hardforums.

RagManX

 

[DaveR]

<< Been done. Awesome stuff. Called BIOS Savior. Available at mwave:

Bios Savior >>



This looks good, but do not know why MWAVE wants $7 shipping.
Also, the status page at IOSS says that the SOYO 6BA+IV is a B1 status. What does that mean? Will it work?

 

[divide by zero]

A means it will absolutely work.
B# means that # of people have reported it to work.
C may mean that it could work but somthing obstructs the BIOS chip, like a card if installed a certain slot.

There used to be a description of these in English but I can't find it at the moment.

 

[DaveR]

<< A means it will absolutely work.
B# means that # of people have reported it to work.
C may mean that it could work but somthing obstructs the BIOS chip, like a card if installed a certain slot.

There used to be a description of these in English but I can't find it at the moment. >>



Great! I clicked on the B1 and it did not even show the 6ba+iv, but it was not quite in English!