HELP: Computer won't boot after changing CMOS battery

[weisbeek]

Hello,

Lately my computer behaved strangely. Sometimes the screen just blanked when I was working with it and I had to reboot the computer (no screensaver involved).
I have also had error-messages from CMOS (checksum errors and such).
The computer is about 3 years old, so I thought it was time to replace the CMOS-battery. I replaced it (quite easy actually) and after that the computer would not boot anymore.
No matter what I tried. I have put the old battery in place again, but that did not work either.
Computer does not react when I push power-button. I have to turn it off by pulling the plug.

Symptoms are like this:
- when turning computer on, harddisk-light turns on
- computer looks for CD-rom (a bootable one, I guess)
- then harddisk-light goes off again
- computer only acts as an expensive airco (it does not do a thing).
- it does not print anything to the screen
- so there is also nothing like "hit del to enter setup"
- no beeps from CMOS
- the monitor just goes into "Sleep mode", because it does not get any trigger from the computer.

Does anybody have any idea what I can try to change this ? I am a software engineer myself, but am currently quite helpless. Normally I can get these things back to live, but they should at least boot...

Thank you very much,

[Richard_Cranium72]

Very Odd indeed.

Try clearing the CMOS

On the motherboard is a jumper stating such or something similar, move the jumper to the clear position then back..

[weisbeek]

A jumper ?
Do you have any idea what it should look like ? There is quite some stuff on the motherboard...

[weisbeek]

Do you know something more about the boot-sequence of a computer. What's the exact role of the BIOS in this process ?
It looks like the computer is waiting for something. But for what ?!?
Currently it is waiting FOREVER...

Thanks in advance,

[weisbeek]

Here at SysOpt I have just found an image of such a jumper (http://www.sysopt.com/cmospass.html), so that should help me out with it.

Greetings,

Martijn Weisbeek
weisbeek.cjb.net

[This message has been edited by weisbeek (edited 03-08-2001).]

[dexmax]

yes, some mobos dont have jumpers, they hav DIP switches.

caddmannq is definitely right. if you can't locate these switched/jumpers take out the cmos battery.

by the way, whats ur ps?



[This message has been edited by dexmax (edited 03-08-2001).]

[BIGO]

you may have unpluged some vital components when changing the battery. Go back in and be sure ALL cards, memory, power connectors, etc. are securely seated after you clear the CMOS.

[linux_guru]

Forget jumpers & switches & stuff. You simply lost all your drives settings when you replaced the battery. Just enter the BIOS and re-setup you drives. You should then be able to boot.

[Lebo]

Put that trout back in the freezer!

The bios holds basic vga drivers (did the post say that there was no output to the monitor, makes it hard to reenter your settings). If the system is making it through POST (and it should definitely be printing to screen) I can't imaging it being a matter of clearing the cmos settings. I would be looking at making sure all components are seated properly. CPU, RAM and Video. Is the monitor conected to the video card? Do you hear the HDD spinning?

[Richard_Cranium72]

Slap me with that frozen tuna, I completely overlooked that he has no activity to the screen..

That must be hardware as in unseated RAM, loose HD cables etc

[weisbeek]

Here I am again.
I am already quite overwhelmed by the number of reactions I got on this post. Thank you very much for your support...

Indeed, without any output to the screen it is quite difficult to change CMOS-settings. If only I had monitor showing something... If only I could enter CMOS and load failsafe-settings or something.

Could I have damaged some vital part by replacing this battery ?!? Could the motherboard be damaged in some way ? How can I check what is working and what is not ? I am really trying to understand the BIOS and CMOS to get an idea of what could be wrong here.

Thanks in advance,

Martijn Weisbeek

[Gyro]

I am having this same problem. The same thing. I installed a new video card and jumped out the onboard card. I am in the navy and work on computers all day http://www.sysopt.com/forum/smile.gif I have never seen this in 5 years. When the computer got to the post it said the battery was dead. I switched of, grounded myself and installed the new bat. power on and nothing. The HDD light comes on and the drives spin, but the power switch does not work. I reseated all cards removeable components to no avail. I UNPLUGGED THE POWER TO THE MOTHERBOARD AND GOT THE SAME THING. I think the mobo might have died a horrible death but am not sure. its currently driving me nutty though.

Gyro

[Gyro]

I think I know what the prob is. Now to figure out how to fix it. The power suppy is an ATX suppy. no way turn switch it. I don't have a switch to change the mobo at/atx Will research and post back later.

R/
Gyro

[weisbeek]

I did not swap anything. I just used a little screwdriver to get the battery out and put another battery (same type and serialnumber) in again. Easy as that.

When I did it I had the entire machine unplugged, so no power involved.

Gyro's reply is kind of interesting. At least I'm not alone in this **** ;-)
And, yes, you're right, my system also has an ATX-powersupply. Can someone tell me more about ATX ? I know that it is some new technology (at least from the last couple of years). But what are the differences / benefits of it ?!?

The fact that the power-button does not work anymore does not really surprise me. Where are the times that those things were just mechanical; they had two settings: on or off, nothing inbetween. But nowadays there is all kinds of electronic involved. You might push it to power off, but it will decide itself whether it will power-off indeed. It is going to look like annoying software (especially Microsoft's).

On Monday I will see the failed computer again and I will look at all wires. Whether they are properly connected and such.
I think I am also going to try placing the harddisk from the failed computer in my other computer (master-slave with the current HD). I'm curious whether that will still boot (I think so) and I can them at least save some software (just in case).
I'll let you know more details when I have them...

When someone has more information to this story, please reply.

Greetings,

[Hellmund]

Maybe the CMOS got zapped by static when u replaced the battery.Did you touch the case to earth yourself before u removed the battery. The CMOS chip tends to be next door to the BAttery so this is quite possible.If it was the ram or cpu you would at least get a beep I would think.Try your in another MOBO and see if they all work.

[captpete]

The basic difference between AT and ATX is:

AT has 5 and 12 volt DC output and has two output plugs that go into the mobo;

ATX has 3.5, 5, and 12 volt DC output and has a single plug to the mobo.

[captpete]

OOPS. That's 3.3, not 3.5

[weisbeek]

Hellmund, I wasn't grounded when I changed the battery. However, the computer was completely powered off and had not been used that day. Is it then still possible to zap the mobo ?
And, if so, can something be done about it or should the mobo just rest in peace forever ?

CaptPete,
If I understand correctly the main difference between AT and ATX is the lower voltages. Is ATX mainly for reducing the power-assumption by the computer or does it also have other benefits ?
BTW, just a hint: you could also have edited your previous message to correct the error instead of replying to it.

Greetings,

Martijn

BTW: why doesn't this messageboard print my signature ?!?

[wildbuffalo]

Recently during my early spring cleaning, I used a pressurized air can to dust off the mother board and all the components in the case. When I restarted the system did not post, same symptoms as HDD, case fans and CD and CRW powering up but no video (screen blank) I shorted the jumper on M/B for clearing the CMOS for five seconds. Reset and reboot, this time every thing powered up and the monitor hissed for like a fraction of second but then died quickly. Next time shorted the jumper for like 30 minutes. Reset and reboot, voila there was initiall boot screen but when it started to detect memory, HDD and CD everything was garbled. I imediatelty pressed DEL key and entered the CMOS settings, loaded the setup defaults and rebooted: the system was back on and working fine.

Just wanted to share my experience on the issue.

Wild

[weisbeek]

Wild,

Thanx for sharing this experience. While it does not sound very promising at first sight, in the end you succeeded in getting this system up 'n' running again.
That's the same as I want to achieve and I do not really care how long that road will be (the shorter the better nevertheless ;-) ). If I eventually succeed ...

Greetings,

Martijn