Real stumper...How to clear the CMOS on mobo w/o battery, jumper, or video?

[SithSolo1]

My friend was trying to fix a computer(It's an old HP) that wasn't booting into windows. He got the bright idea to change the video settings in the BIOS from PCI to AGP and then he saved it. But wait! There is no AGP slot so now he can't see anything. He opened up the case and looked around but he says he sees no removeable CMOS battery or jumpers. Any ideas here would be great.

 

[Viper96720]

How can there be no cmos battery? What model HP is it? There has to be a way to reset the bios.

 

[owensdj]

I would try searching the HP web site for a downloadable version of the user manual for that computer. If you can't find one, try posting this question in the HP tech support forums on the HP site. Someone might know how to clear it.

Seems like there should be a CMOS battery in there somewhere.

 

[buckmasterson]

Knowing HP, the battery is there, and it's hiding under something, and you'll have to remove the motherboard to get to it!!! Acers had this problem too...

 

[Jeff7]

An old 386 motherboard I used once had the CMOS battery soldered right to the motherboard - a rechargable battery though, a NiCad.

 

[Regs]

Duel BIOS should be a standard on all motherboards.

 

[SocrPlyr]

Originally posted by: Regs
Duel BIOS should be a standard on all motherboards.

Please explain to me how Dual Bios would help in this situation... Bios and CMOS are two separate things.

PS a Duel is a fight or conflict between two opposing things (including people and ideas).


Back on topic as was mentioned before many manufacturers use special batteries or hide them. Your best bet is to find the mobo manual for it or look at every little section of the board one by one... removing all the cables and card also may help you get a clearer view of the board.

Josh

 

[Regs]

By pressing F1 during boot (or other key trigger you designated in the dual bios set up), will load the defaults in the bios. Problem fixed. And you're right, the CMOS and BIOS are two separate things. However he is trying to reset the CMOS to load the defaults back in the BIOS which Dual Bios is suppose to do with a click of a key.

And yes, thanks. Typo monster is after to me.

 

[SocrPlyr]

Regs I know what you are trying to say but I just feel you don't have a good understanding of how it works. Your bios are cannot be changed, unless you are flashing them there is absolutely no way to change the bios (with a few exceptions). Now within the bios there is a program to change certain settings that help define what hardware you have in your computer. Now these settings are not saved in the bios (becasue they cannot be), but they are saved in the CMOS. and the CMOS is volatile memory IE if you remove the power it loses what was stored there (this is how the clear CMOS jumper works it removes the power connection to the CMOS and finishes a circuit so the memory can discharge). the point of dual bios is to protect against a bad flash or a virus the kills the bios, which is totally different from his situation. in that case something has to address the flash rom in a specific way to overwrite it...

Josh

Edit: Now Regs, i am not sure how the dual bios is implemented and it could be different from one manufacturer to another but i would guess that by default restoring the bios from the secondary chip would reset the CMOS, thereby fixing the problem. However, that is a side effect but not that actual process, clearing the CMOS is a much simpler and less troubleful process. Dual bios just isn't the answer to a problem like this because there is no problem with the bios being there. (altho there may be a flaw in the bios that doesn't go back to the agp after it doesn't find a pci card tho... which it should)

 

[Regs]

You're right Josh. The BIOS cannot be changed and all the settings are saved in the CMOS. Yet when you use a completely different BIOS (duel bios) you should have the stock settings of which of the BIOS contained when it was shipped from the manufacturer, over writing the current CMOS. Even so, duel bios comes with built-in settings in which you can reset the CMOS (not the bios) on a key stroke during boot. My apologies.

If the only problem you are experiencing is the lack of video, sithsolo, then I would check your manual for:

A. The key to access bios on boot
B. The key to load optimized settings for CMOS
C. Use those two keys in sequence, then press enter.
D. Restart the PC

You just have to use guess work in what you would see on the the screen if it had video I/O.

 

[SocrPlyr]

Regs
I see what you are saying about the DUAL BIOS options, just something to think about... why isn't there a keystroke to clear the CMOS?... in the same manner that the dual bios keystrokes work... anyways my point was he shouldn't have to go the level of changing the bios (or switching in the case of dual) to do something that is universal amongst all boards (clearing the CMOS)

Josh

 

[Viper96720]

Some recent boards you can press a key on the keyboard to reset the bios to the defaults. With mine it's the insert key.

 

[oldfart]

Download and run clrcmos.exe Maybe set up an autoexec.bat on a floppy.