Dead battery on a 486 motherboard? Who remembers the good ol days ? :)

Forums › Desktop computing › Dead battery on a 486 motherboard? Who remembers the good ol days ? :)

cgreenwood

201 posts

Master Geek

#102640 18-May-2012 18:04

I work in a Medical laboratory and have some automated blood analysers that are getting a little on the old side. They have an old 486 PC integrated into them as the brains of the operation. Today after one was powerd off and then powered on (probably too quickly, the standard 10 second wait was not observed) and when the PC was booting up it gave an error something along the lines of "the battery is flat" don't remember the exact wording, and will go no further. Anyway; no amount of playing with the CMOS setting will change anything, in fact all settings changes are lost everytime the power is turned off so it really does sound like the wee battery that is usually to be found on the motherboard is flat. The problem is that there is no battery on the motherboard that I can find.

So my questions are thus:

1. Is there a battery somewhere that I am missing?
2. Would it be replaceable if I did find it?
3. Is the motherboard dead?
4. Where the heck would I find a replacement 486 motherboard?

Any other clues as to what might be going on here would be appreciated.

Thanks.

mxpress

376 posts

Ultimate Geek

#627446 18-May-2012 18:17

cgreenwood: I work in a Medical laboratory and have some automated blood analysers that are getting a little on the old side. They have an old 486 PC integrated into them as the brains of the operation. Today after one was powerd off and then powered on (probably too quickly, the standard 10 second wait was not observed) and when the PC was booting up it gave an error something along the lines of "the battery is flat" don't remember the exact wording, and will go no further. Anyway; no amount of playing with the CMOS setting will change anything, in fact all settings changes are lost everytime the power is turned off so it really does sound like the wee battery that is usually to be found on the motherboard is flat. The problem is that there is no battery on the motherboard that I can find.

So my questions are thus:

1. Is there a battery somewhere that I am missing?
2. Would it be replaceable if I did find it?
3. Is the motherboard dead?
4. Where the heck would I find a replacement 486 motherboard?

Any other clues as to what might be going on here would be appreciated.

Thanks.

mxpress

376 posts

Ultimate Geek

#627448 18-May-2012 18:21

there is a battery in the board as on ALL motherboards. On a 486 it will probably be soldered to it. I suggest not turning it off, if it has lasted this long it will keep going if not turned off.

Or on boot up, push DEL to go into bios and find setting to ignore errors. As long as the power (hot point) is not turned off, it should be fine.

mxpress

grant_k

3539 posts

Uber Geek

Trusted

#627453 18-May-2012 18:30

Yep, I remember this problem. There is a RTC (real time clock) chip which has a Lithium battery inside it. You need to unsolder the chip to replace it, and then you would need to get exactly the same type of chip. Not easy nowadays, although Element14 or RS Components may be able to help. Then you need someone with a vacuum de-soldering machine who knows how to use it, or otherwise the main board will be damaged.

While this sounds a stupid way of encapsulating a battery on the main board, the fact is that these chips had at least a 10 year life which was expected to be sufficient for a PC. Trouble is, some manufacturers of embedded boards also used them, and that is why you find yourself in this situation.

Have you tried asking the local agent who supplied the blood analyser to your laboratory?
They should be able to provide a replacement board for you.

stevenz

2802 posts

Uber Geek

#627629 19-May-2012 09:14

Some of the later 486 boards will have a standard lithium (2035 or similar) battery on them, not hugely common though, mostly they didn't change to these until the Pentiums.

Most had replaceable plug-in battery packs which you probably wouldn't have a hope of finding now, but if you can unplug the old one (should be obvious what it is if you have a look) then you can make a custom one from standard lithium cell(s), a couple of wires, some solder & some electrical tape.

Otherwise, it may be one of the integrated ones as grant says in which case your only option is yes, to never turn it off again.

@KnightNZ

gjm

808 posts

Ultimate Geek

#627635 19-May-2012 09:31

If possible I would suggest powering it up and then p2v-ing it so it runs as a virtual machine in vmware or something similar. Not sure it if will work on something that old but if it does then you take the old hardware picture and can run it on something better

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gzt

17104 posts

Uber Geek

Lifetime subscriber

#627643 19-May-2012 10:02

gjm: If possible I would suggest powering it up and then p2v-ing it so it runs as a virtual machine in vmware or something similar. Not sure it if will work on something that old but if it does then you take the old hardware picture and can run it on something better

This might not be a straightforward approach with proprietary hardware involved. It might also break any certification the device has.

gzt

17104 posts

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Lifetime subscriber

#627645 19-May-2012 10:05

cgreenwood:1. Is there a battery somewhere that I am missing? 2. Would it be replaceable if I did find it?

Take a photo and insert it here.

Usual technique is upload it to something like http://www.picwizz.com/ then click the insert image button and paste the url it will give you.

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cgreenwood

201 posts

Master Geek

#627714 19-May-2012 14:48

Thanks for all your help and advice. We have contacted the analyser supllier and they are going to fit a replacement PC harvested from an old parts machine. The analysers are over 10 years old so that fits with the 10 year life for the batteries, the only problem is that the replacement PC will be just as old as the old one and so I guess we can expect the battery on that one to fail soon too.
Unfortunatly never turning it off is not an option, the analyser has to be restarted every so often to clear errors that can't otherwise be cleared, otherwise it stays on 24/7, I guess that it why it has taken a while for this problem to rear its ugly head. These analysers are old and really need to be replaced, we are working on that with the people who write the cheques but when there is mnoney involved it is never easy, the they are far from cheap.

PS

Usual technique is upload it to something like http://www.picwizz.com/ then click the insert image button and paste the url it will give you.

Not quite sure what you mean by this but when I follow this lnk, AVG gives me this:

So donlt think I will go that route.

Azzura

603 posts

Ultimate Geek

ID Verified

#627801 19-May-2012 21:32

Most likely any battery that meets the specs of the old one...could be hardwired in creatively.

grant_k

3539 posts

Uber Geek

Trusted

#627802 19-May-2012 21:36

Azzura: Most likely any battery that meets the specs of the old one...could be hardwired in creatively.

And how would you suggest doing that if it's inside a chip, enclosed in epoxy resin -- as in this case???

The type of chip commonly used on these mainboards was a Dallas DS12B887 as shown on this datasheet:

http://pdf1.alldatasheet.com/datasheet-pdf/view/58476/DALLAS/DS12B887.html

As you can see, the Lithium battery is totally enclosed, and they say the life is over 10 years in the absence of power. I sold thousands of boards like this in a previous life!

mattwnz

20141 posts

Uber Geek

#627803 19-May-2012 21:36

cgreenwood: Thanks for all your help and advice. We have contacted the analyser supllier and they are going to fit a replacement PC harvested from an old parts machine. The analysers are over 10 years old so that fits with the 10 year life for the batteries, the only problem is that the replacement PC will be just as old as the old one and so I guess we can expect the battery on that one to fail soon too.
Unfortunatly never turning it off is not an option, the analyser has to be restarted every so often to clear errors that can't otherwise be cleared, otherwise it stays on 24/7, I guess that it why it has taken a while for this problem to rear its ugly head.? These analysers are old and really need to be replaced, we are working on that with the people who write the cheques but when there is mnoney involved it is never easy, the they are far from cheap.

PS

Usual technique is upload it to something like http://www.picwizz.com/ then click the insert image button and paste the url it will give you.

Not quite sure what you mean by this but when I follow this lnk, AVG gives me this:

So donlt think I will go that route.

I think that could mean that their website has been hacked and has malware on it.

Lias

5589 posts

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Lifetime subscriber

#627804 19-May-2012 21:46

A lot of the old boards that had soldered/hardwired batteries, had a connector for an external battery on it..

4 pin connector with one pin removed from memory,

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grant_k

3539 posts

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Trusted

#627805 19-May-2012 21:50

Lias: A lot of the old boards that had soldered/hardwired batteries, had a connector for an external battery on it..

4 pin connector with one pin removed from memory,

Embedded boards with the Dallas DS12B887 had no such connector because the battery was internal to the chip. Instruments like the Blood Analyser mentioned by the OP are usually fairly compact and don't have room for batteries on the board. This is why so many of these boards used the Dallas chip, because it saved space, and they didn't want any "User Replaceable" parts inside.

Azzura

603 posts

Ultimate Geek

ID Verified

#627810 19-May-2012 22:30

Did I miss the OP saying he had a "Embedded boards with the Dallas DS12B887"?

But if it was what he has (most likely it is..since you seem to know, grant), and depending on how much fun/creative I wanted to be. I would try getting the old RTC out/off the MB and buy one of these - www.aliexpress.com/fm-store/507025/211035049-451612026/Free-shipping-wholesale-retail-brand-newDS12C887-DS12B887-DS12887A.html and try to put it in (?).

But the whole idea is pooched if he can't buy it from the link above in the firstplace. And I am only guessing that the points go through the MB to the bottom.

There is always hope and a way....I think?

And if you want to get creative...could he do this? - http://www.mcamafia.de/mcapage0/dsrework.htm

gzt

17104 posts

Uber Geek

Lifetime subscriber

#627820 19-May-2012 23:31

mattwnz:
cgreenwood: Thanks for all your help and advice. We have contacted the analyser supllier and they are going to fit a replacement PC harvested from an old parts machine. The analysers are over 10 years old so that fits with the 10 year life for the batteries, the only problem is that the replacement PC will be just as old as the old one and so I guess we can expect the battery on that one to fail soon too.
Unfortunatly never turning it off is not an option, the analyser has to be restarted every so often to clear errors that can't otherwise be cleared, otherwise it stays on 24/7, I guess that it why it has taken a while for this problem to rear its ugly head.? These analysers are old and really need to be replaced, we are working on that with the people who write the cheques but when there is mnoney involved it is never easy, the they are far from cheap.

PS

Usual technique is upload it to something like http://www.picwizz.com/ then click the insert image button and paste the url it will give you.

Not quite sure what you mean by this but when I follow this lnk, AVG gives me this:

So donlt think I will go that route.

I think that could mean that their website has been hacked and has malware on it.

Geekzone does not provide photo upload, so if you want to upload a photo you need to upload it to an image hosting site, then use the 'insert image' button on a geekzone post and link to the url that the photo hosting site gives you.

I'm really really sorry I sent you to an image host which generated a security alert.

False positives are not uncommon but it is far better to be safe than sorry.

- gzt.