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CMOS Battery Question

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muthabored

Technical User
May 5, 2003
391
US
Gooooooooood afternoon!

A friend of mine has an HP Pavilion running Win98.
He had a sound card in the PC that he wanted to install and he wanted to upgrade the RAM. He went out and got everything on his own and installed them but when he went to boot his PC, NOTHING...dead, dead, dead...no lights, no fans spinning on the processor or power supply...NOTHING.
I took the case off and checked to make sure that he didn't accidentally unplug something and everything was cool. I then removed the CMOS battery, waited a second or two and reinserted it...PRESTO! The thing boots up. I then shut down the PC with Start/Shutdown and it did but when I tried to boot it again the normal way, nothing. I took out the battery again, waited, put it back in...PRESTO! Could the problem be that his CMOS battery is going bad OR could it be that there is a jumper on the systemboard that is missing or in the wrong place? There was a CMOS checksum error that I can't remember verbatim (I'll post it when I get home). Am I headed in the right direction?
 
the checksum error usually indicates a dead battery unless the battery was removed..which you said you did. did you see this checksum error after that? I have never seen one that would keep the system from powering on though...dont know if it is possible or not but there might be a problem with one of the controller chips locking up that would keep it from powering on and by removeing the battery it would release it allowing it to boot...if that is the case you would be looking at a new board...but the first thing to do would be to remove the ram and the soundcard he installed and see if the system returns to normal..then try adding the ram first and see how it does, if everything ok add the soundcard...if not remove the ram and add the sound card first and test, then the ram
 
I forgot to mention that the parts that he installed (RAM, sound card) we removed and the original RAM and sound cards we put back into the unit...nothing. So I added each one at a time (RAM first and the sound card). It's weird because the only way the PC would boot from a normal system shutdown is if the CMOS battery was removed and then replaced after about 15 seconds or so. After removing the battery the first time and reinserting it, the PC did power on and it was at that time that I saw the CMOS checksum error (I'll try find the piece of paper that I wrote the error on). I did mention to him that it could be the MOBO.
 
muthabored,

You did not specify the Pavilion model, if you can it would help.

I will just give a general rule of thumb for the HP Pavilion series. Other than a fax/modem board, everything else is part and parcel of something else. What you may believe was the sound board could also be the usb, keyboard and video ram board. There is a lot of integration on the boards on the PCI bus, and very few can just be removed. And very few are just a sound board, or just a video board, etc..

By pulling the battery you can fool the BIOS momentarily, but once it starts building its internal table of devices you are in trouble.

Best general advice: RAM should be fine as an upgrade. For the rest leave the default devices there and get a good solid boot into Windows without errors.

Use Device Manger to disable, not uninstall, the device you want to replace.

Do an orderly shutdown.

Restart, and if there is a BIOS option for the device either disable it there, or set it to the least footprint setting possible.

Save settings, and shutdown.

Replace the part now with your add-on.

Restart. Pray.
 
Got it. I can't remmeber which model of Pavilion he has.
I also looked for a jumper on the systemboard that was near or right next to the CMOS battery but couldn't find one.
 
Most likely you are grounding out on or within something. Check under the mother board to ensure there are no extra standoffs. Standoffs are the little metal haxes or clips the screws holding your m/b in place.
 
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