How can I clear CMOS on a laptop with no CMOS battery and a dumbed-down BIOS setup program?

[CZroe]

See title.

I've trouble-shooted a laptop's problem (Locking up as soon as a Wireless cad is inserted) to a positive resource conflict. 98 will not let me change the resource assignments in safe mode and will lock up when attempting to normally. I need to clear the PnP info so Windows will re-detect everything. Thnx!

 

[jmatt]

A jumper can be moved on the motherboard .

On boot up , hit the pause button . Down the bottom of the screen is a long list of numbers .
This contains the code needed to identify your motherboard .
Press the space bar to move off pause .

Tracking motherboard & bios maker etc ,
http://www.wimsbios.com/
http://duxcw.com/digest/Fromshop/mb/det.htm

http://www.ontrack.com/JumperViewer/

http://www.thetechpage.com/cgi-bin/default.cgi

 

[CZroe]

Forgot to mention: Most laptops do not have CMOS clearing jumpers. This is to thwart a theif's attempt at clearing CMOS passwords to access data.

 

[Lord Evermore]

You can't just squiggle the knobs, then hold it upside down and shake it?

 

[jmatt]

Try this .
Start up with your Boot disc or Startup disk in ( without cd rom support )
At the A: prompt , type > sys c: & press ENTER.

Take out the boot disk & restart your computer.

-----------------------------------

Or , this .

To reinitialize W-9x hardware drivers and leaving your settings
intact:

Run REGEDIT

Click The ( + ) sign HKEY_LOCAL_MACHINE
Export Enum to a floppy to save , then
delete the ( Enum ) and re-boot with CD or Disks in hand .

Windows will ask you to provide the disks for your drivers and you
may need to re-boot many times.

As usual , before you start , Backup , Backup , Backup .

 

[Lord Evermore]

I would assume that you just need to look up the manual online for the brand and model of laptop...

 

[VBboy]

It is very easy to open a laptop and locate the CMOS battery, especially on newer laptops. This of course will void your warrantly unless you're careful. I've done this several times on various laptops with 100% success rate.

 

[bacillus]

I agree with jmatt on deleting the enum registry key then rebooting.
win98 will have to redetect all the hardware on restarting.

 

[jmatt]

Opp's , the sysc part I meant to put , try >

Boot with the startup floppy and get to the A:\> prompt .

Once there type fdisk /mbr & press Enter .

 

[Nack]

I wouldn't say "very" easy, but I have to agree with VBboy on this one. Are you SURE it doesn't have a CMOS battery? I just completely took apart a Thinkpad (for purposes of an upgrade), and found the CMOS battery about 1/4 way into the teardown. Anyone who can build a desktop should be able to get as far as the CMOS battery on most laptops. Download/find the repair manual for your laptop - I bet it is in there somewhere.

Nack

 

[CZroe]

I know that many laptop's do not have one and use flash just like Intel-manufactured motherboards for security reasons and I can't open this latptop regardless. It's a customer's. There's no telling how many times I've opened other laptops!

I own about 300 unused laptop CMOS coin cell batteries, so trust me: I know that some take CMOS batteries (Anybody need any? )

Thanks for the registry tip! I'll try that... Will this work if the BIOS is in control of PnP resource assignments? The dumbed-down CMOS Setup Program doesn't have the option to switch... I mean, I doubt it's a driver problem so simply redetecting the hardware without assigning different resources may not help.

I guess this has turned into a software question now

 

[Lord Evermore]

I have to ask again...why not find the manual?

 

[jmatt]

http://www.computerhope.com/issues/ch000235.htm

Under the keyboard or bottom of laptop - If you are working on a computer laptop the location of the dipswitch (almost never a jumper) can be under the keyboard or on the bottom of the laptop in a compartment such as the memory compartment.
Other visible location - While it is possible that the jumpers / dipswitches may not be in a visible location, most manufactures try to make things easier by placing the jumpers / dipswitches in another visible location.

Additionally, when looking for the jumper / dipswitch the label of that switch can be anything however in most cases will be labeled CLEAR - CLEAR CMOS - CLR - CLRPWD - PASSWD - PASSWORD - PWD.

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http://www.computerhope.com/rdebug.htm

The following debug routine will clear CMOS, BIOS, Passwords, Settings, Viruses, and other items residing in the CMOS. During this process you may get returned characters which are an indication that the string has gone in, if you by chance get ERROR ensure that you have typed the line in correctly, if not retype. Ensure that you do not skip any lines, that it is ALL typed in correctly to help prevent problems. Before running this Debug routine also ensure that you have read the above disclaimer.

After typing debug you will get "-" which is were you can begin by typing A and pressing enter.

A <ENTER>
MOV AX,0 <ENTER>
MOV AX,CX <ENTER>
OUT 70,AL <ENTER>
MOV AX,0 <ENTER>
OUT 71,AL <ENTER>
INC CX <ENTER>
CMP CX,100 <ENTER>
JB 103 <ENTER>
INT 20 <ENTER>
<ENTER> Note: Nothing is typed on this line
G <ENTER> By pressing G this will execute the above script, ensure you have read and agree to the above disclaimer.
Q <ENTER>

Then reboot and you will get a Setup Checksum Error. Go into setup, correct all the incorrect values, time, date...

 

[RalfHutter]

I've worked on a couple of Dells that let you reset the CMOS if you pushed a paperclip into a little "reset" hole on the right side of the case and kept a certain key pressed down during bootup. Maybe there's similar methods for other laptops as well.