We help IT Professionals succeed at work.

How to reset CMOS via power on

slsrlsden asked
IBM ValuePoint 6482 machine type, L5F model number DX33.  Playing with CMOS video to check a synch problem with a monitor. Now monitor blank,  nothing period,even on known good monitor. Post 1,3,2 short beeps.  How can I power-on reset/clear  CMOS?  Have removed CMOS battery for hours.  Have disabled on board video and tried to use a video card to get back into CMOS.  Still get Post 1,3,2 beep.
Watch Question


Edited text of question
Is the video card on board or addon card ?
If it is addon card did you try to reinsert it?

Did you say sync problem... some monitors with energy saver features will swich off without sync... USE a post card in the computer to get the exact error code

At this point it most likely isn't a CMOS setting.

Can you hear the memory test? Floppy drive seeking? (This gives us an idea of how far the BIOS program is getting before it hits the error).Are the post codes listed in your manual?

Check RAM and CPU seating.Make sure all the jumpers are back where they belong.Pull all cards including the add-on video.

memory might be fried... (that is your RAM)

1-3-2 beeps usually means "the motherboard is bad", according to my sacred hardware papers. So...

Anyway, replace the battery for a new one - and reset the CMOS via its respective jumper on the motherboard.

Hope this will help you.


Rodrigo Faustini

Has your CPU been changed?
Info I've found on your model seems to indicate 486DX2-66.
What kind of monitor/s are you testing with?
How much RAM in the system?


Your right, model indicates it is a indicate 486DX2-66, but I have a DX33 cpu installed.  
   CPU is verified good (other machine)
   memory verifed good(8M, other machine)
   monitor verified good (another machine).

***** Problem only started after changing CMOS to test a 2nd questionable monitor I had. Machine has booted with these componets to CMOS.

Before I changed CMOS video, machine did check memory without problem. Now,it does not sound like it does a memory test. Beep code 1-3-2 immediately upon cold boot.

I originally was able to get to cmos with on-board video. I only disabled onboard video via jumper and put an add-on video (verified good) to try to get to CMOS that way. Still 1-3-2.

If I remove memory all together, beep code is 1-3-1, indicating a memory test/refresh failure per IBM. So...it probably is getting past memory boot check.

**** CMOS video config is the only thing that has really changed since machine last booted to CMOS OK, and is why I'm trying to figure out how to get back to defauld CMOS settings without being able to view screen.

There is no jumper on board anywhere that would indicated it could be used as a CMOS reset.  Thats why I removed battery for several hours.

IBM site has reset procedures varying from jumper, battery removal, to pressing key/mouse combinations during cold boot to reset CMOS on several other models but nothing for 6482 L5F.  

Nothing on their site that would indicate 1-3-2 as being a bad motherboard
(faustini,what is the source of your sacred hardware papers?)

I do not have any documentation...and is why I'm posting question   @ experts-exchange.

Just short of removing battery again, and using foil to discharge any and all capacitors on board, one would think there has to be a way to put CMOS back to a default setting.

The beeps during POST might indicate that your video card is not making connection. Try re-seating the video card. Be especially attentive to AGP cards - the socket that they sit in is less forgiving than PCI.

You may also want to verify if the video card has gone bad. Just use a different video card in the same socket to see if it works.
IT is 486 with no pci or agp cards. Did you try to enable on board video card and try to boot few times alsp did you try to remove power connections on motherboard and reinstall them ?

I am not completely familiar with that IBM board, but I know that most IBM boards do have a Cmos clear jumper on them.

IBM classifies the 1-3-2 beep combo to be either a memory problem, or a system board problem.Here are the codes

1-3-1 & 1-3-2 = memory or sys board
1-4-4 = Keyboard or sys board
2-1-1 & 2-1-2 = RUn setup or sys board
2-2-2 = video card or sys board
2-3-2 = memory or sys board
2-4-3 & 2-4-4 =run setup or memory or sys board

All other beeps = sys board.

Let me read to you what IBM wrote in their manual:

"If the screen is rolling, replace the display assembly. If that does not correct the problem, replace the system board."

First things first: make sure the video cable is connected securely to the computer and monitor. I was trouble shooting a video display about 2 weeks ago, and after a while working on it, I did that, and the display came back, so this is the 'friendly reminder' to do so.

Reseat the memory. If the video is a card, then re seat that. If you have another video card, try switching. See if you can get past that beep.

You mentioned that you have a 33 in the machine, and it is supposed to be a 66? If that is so, then make sure all the jumpers are correct, including the cache jumpers.

Look for a CMOS clear jumper. Try that with the battery.

Let me know what happens. In the meantime, I will dig up some more articles on this machine.

Try hitting Reset after the POST error (instead of cycling power).There are some situations where doing this will allow the system to boot.

Try to remove the battery and short-circuit its connections at the motherboard with a piece of wire. Then, if there any capacitors near the batttery socket, short-circuit those too. Replace battery and try to boot up.

Or, try to hold Insert or End keys during power-up (clears CMOS on some BIOSes).
Tim HolmanCEO and Founder

  If memory is OK then this is a system board problem.
  IBM's recommendation would be to replace the system board....


You should see principal sheme of your motherboard(you must have it because it's given when you buy a comp). If you don't have, you should see yourself. There should be switchers/jumpers on your motherboard. There should be reset CMOS jumper. You should
switch it, then boot and set what you want


Principal sheme of the motherboard is under the hood. As stated previous problem descriptions, there is no reset CMOS jumper in diagrams or jumper marked reset anywhere on the board.

faustini, I found sacred IBM docs on IBM UK site that do indeed indicate a beep 1-3-2 as a bad motherboard or memory.  Memory has been verified good....so, must be motherboard.

faustini, could you please post another proposed answer.  I wish to except your original proposed answer.

Sorry j_powers and tim_holman.  You were both right but faustini suggested it first, but faustini answer was originally rejected.  THANKS to all...the follow up questions were very logical and ALL had good suggestions.  You are all indeed experts.
Some kinds of motherboards has a jumper that clears the Cmos.
It seems that yours doesn't have one.
Then, remove the battery, and make a short-circuit on the battery terminals, for some seconds, to clear the CMos.