Solved I need assistance with a Windows 95 Computer.

Microsoft / Windows 7 enterprise sp1(...
April 30, 2019 at 07:50:44
Specs: Windows 7, 4096 D MMb
I have a few questions regarding Windows 95. When my PC starts up it shows the following: CMOS Checksum error. - defaults loaded. CMOS battery failed. Press F1 to continue. And then the PC starts up with no problem and yes, the date and time is up to date. I have downloaded the manual for this motherboard. It's a Pentium GA586ATV ref 1A but on the diagram and even looking for the battery physically, I couldn't identify it. Anybody willing to assist please.

As I said it's Windows 95 .

When was the last time you did something for the first time?


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✔ Best Answer
May 1, 2019 at 02:30:39
"Benchmarq bq3287 MT"

That's your RTC/battery. Unfortunately just an offshoot of the Dallas DS1287.

https://www.digchip.com/datasheets/...

Are you sure it's not socketed?

"Channeling the spirit of jboy..."



#1
April 30, 2019 at 08:08:15
Likely a Dallas battery (which isn't easily replacible without decent soldering skills). Is one of the chips marked "DALLAS" on top?

"Channeling the spirit of jboy..."


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#2
April 30, 2019 at 08:39:45
As T-R-A intimates, most computers of that age used a rechargeable battery that was soldered to the motherboard rather than the replaceable batteries in today's computers. It will probably be a blue cylinder (a bit like a capacitor) lying horizontally on the board. There will probably be markings on the m/b to identify it.

Not too difficult to replace with a pair of wire snippers and a soldering iron. The problem may be to find a suitable replacement.

Edit: There's a video here that may be of interest: https://www.youtube.com/watch?v=1-S...

Also, some interesting hits if you Google "rechargeable cmos battery". In particular, http://pc-restorer.com/replacing-cm...

message edited by ijack


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#3
April 30, 2019 at 08:52:11
But the Dallas RTC wasn't rechargable. It was designed to last around 5-7 years... which was considered to be the life of the PC it was installed into. If it's a Dallas, it would look like this:

https://www.classic-computers.org.n...

Hopefully it's not the dreaded 1287 (which requires more than just soldering skills to get working again).

http://www.mcamafia.de/mcapage0/dsr...

"Channeling the spirit of jboy..."

message edited by T-R-A


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Related Solutions

#4
April 30, 2019 at 09:48:37
I think it's unlikely that a Pentium PC had a discrete RTC chip. Wasn't the RTC built in to the Southbridge chip?

I assosciate those RTCs more with AT and PS/2 class computers. The rechargeable batteries that I mention were widely used on Pentium class computers. If you're lucky it's one that just plugs in rather than being soldered, but certainly a lot of Dells, HPs, and Compaqs used the soldered batteries.


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#5
April 30, 2019 at 10:34:17
I've repaired several Pentium class machines (and a couple PII's) with a Dallas chip. Usually they were on lower-end machines that put price over performance. They were more common in PS/2's, but we still have them in lots of equipment at work.

"Channeling the spirit of jboy..."

message edited by T-R-A


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#6
April 30, 2019 at 11:55:55
Hi ijack. I combed the MB but see nothing that looks like a battery of any sorts. I found reference to the battery in the user manual and I know now it is a 3V Li-battery that lasts only about 5 years. Physically...nothing.

When was the last time you did something for the first time?


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#7
April 30, 2019 at 12:15:03
Here's the motherboard layout:

https://stason.org/TULARC/pc/mother...

You see the rectangular shaped 'real time clock' by the bios. It's shape indicates it's probably one of those Dallas-type batteries. Some of those motherboards had a 4-pin connection to add an external battery but that isn't shown for that one.

If the clock is right once it boots then try configuring the bios properly and see if it then boots up without the bios errors.


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#8
April 30, 2019 at 13:06:51
It has a Dallas RTC battery (or possibly Odin). They're not soldered to the board, they fit in a socket. Here's a way to attach a 3.3v lithium: https://www.classic-computers.org.n...

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#9
May 1, 2019 at 01:12:39
Hi Dave. Sorry to reveal my ignorance. How do I configure the Bios?

When was the last time you did something for the first time?


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#10
May 1, 2019 at 01:18:29
riider, there's nothing that sits in a socket but there ar etwo distinct rectangular shaped items what I would call maybe resisters. The one is called Benchmarq bq3287 MT and I googled it. Talks about it being some sort of resister.

When was the last time you did something for the first time?


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#11
May 1, 2019 at 01:21:21
Sorry not resister but semiconductor.

When was the last time you did something for the first time?


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#12
May 1, 2019 at 01:27:02
The other rectangle has the ff inscribed: Award software Inc. 1995. All rights reserved. PCI/PNP 586. S/N: 051365091.

When was the last time you did something for the first time?


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#13
May 1, 2019 at 02:30:39
✔ Best Answer
"Benchmarq bq3287 MT"

That's your RTC/battery. Unfortunately just an offshoot of the Dallas DS1287.

https://www.digchip.com/datasheets/...

Are you sure it's not socketed?

"Channeling the spirit of jboy..."


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#14
May 1, 2019 at 05:01:08
No it's not socketed. In their website they refer to it as a semiconductor.

When was the last time you did something for the first time?


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#15
May 1, 2019 at 05:36:10
" In their website they refer to it as a semiconductor"

In a sense, it is. It's a real-time clock (RTC) module...the circuitry that keeps time integrated with the battery to keep it (and the BIOS settings) active. You mentioned that your time was correct...does the machine keep the HDD settings when you power-cycle it?

"Channeling the spirit of jboy..."

message edited by T-R-A


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#16
May 1, 2019 at 05:44:21
I've worked with plenty of those old socket 7 boards. DAVEINCAPS posted a link to your board showing the location of the RTC battery. It sits right next to the CPU. You wouldn't know it sits in a socket until you pry the battery out.

Battery in place: https://2.bp.blogspot.com/-lQtUGwBs...
Socket after battery removed: https://4.bp.blogspot.com/-oqw0evMX...

This should be your motherboard; notice the battery next to the CPU at the bottom edge of the board:
https://thumbs.worthpoint.com/zoom/...

Obviously an extremely old board. Socket 7, AT power (not ATX), 72-pin SIMM memory (which must be installed in matched pairs), PCI & ISA slots, cache memory slot, no onboard ports other than keyboard. All CPU settings are configured via jumpers rather than within the BIOS. Those were the days!


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#17
May 1, 2019 at 06:06:25
Amazingly it does bearing in mind that this pc had not been in use since about 2005. Yes it must be the Benchmarq bq3287 chip. Wonder if it's worth bothering as it still powers up without a hitch. You only need to press F1 when asked.

When was the last time you did something for the first time?


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#18
May 1, 2019 at 06:42:46
"Wonder if it's worth bothering as it still powers up without a hitch. You only need to press F1 when asked."

Depends on how willing you are to put up with it. But eventually the battery will drain to the point where no settings (including time) will hold. If you want to hang on to the machine, follow one of the links that either riider or I gave to make the modification of the module. Just realize that it needs careful detail if you attempt it, and if the module is soldered to the PCB, you'll have to desolder it without damaging it or the PCB.

"Channeling the spirit of jboy..."


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#19
May 1, 2019 at 07:29:24
Eish! I'm not sure I'm up to that. With eyesight not so good anymore, I doubt if I should tackle such a task. But thanks for your time and responses.

When was the last time you did something for the first time?


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#20
May 1, 2019 at 12:44:30
Then find a local computer/electronics guru willing to do it for a nominal fee. Personally, for me it's pretty easy... but then I do component-level repair on a daily basis.

"Channeling the spirit of jboy..."


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#21
May 1, 2019 at 13:37:30
I don't know if they still make those but you may want to look around for a replacement. Check online. Also there's a chain of brick and mortar stores called 'batteries plus' that may have it. Note riider's link above about modifying your existing one with a 3.3 v lithium.

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#22
May 2, 2019 at 06:31:30
Thanks guys. You have all been very helpful. And yes, I will do it. I'm very handy with welding and soldering it's just the eyes that are playing the game.

When was the last time you did something for the first time?


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