Uncreative Labs

Guest

Hi,

I've got an IBM PS/1 2011. The CMOS battery has died and I want to replace it. I can get hold of a replacement easily enough but there's two ponits I'm unsure of.

1) Where on the Mobo is the battery?! I can't see it anywhere Embarassed

2) How is it attached? Does it need soldering? Do I need 'a solder flow device'? Some corporate advice says I can't just solder components on myself but I have with a 386. Are there gonna be any complexities in replacing the battery?

Cheers,

Posted: Tue Jul 19, 2005 12:18 am

Are there any chips marked "Dallas?"

Posted: Tue Jul 19, 2005 5:05 am

If the PS/1 type 2011 is like the PS/1 type 2121, the battery is a flat round one clipped in place under the internal modem. I think there were lots of different PS/1s, though, so yours might be different.

Guest

Hi. Thank for the advice thus far.

The machine is the UK edition of the 2011 (286 @ 10MHz - 1MB RAM.) The UK version had a serial port card rather than a modem. (You wouldn't get IBM support during normal office hours in the UK!) I have taken the machine apart trying to find the battery and have not seen a round battery at all. Having said that.. I am not sure I have physically removed the serial card... I will double-double check. I will also get back to you re: the 'Dallas' chip.

Many thanks.

Guest

Sorry about the delay in getting back to you. Internet access is difficult for me these days.

There is no round CMOS battery under the serial card but there *is* a 'Dallas' chip to the right hand side of hte board. It is also marked 'Real Time Clock.' (This would have been my guess for where the CMOS battery was located but it doesn't look like any battery I have ever seen before.

What's the score on replacing this? Can another chip or component be soldered onto the board at home?

Again, many thanks.

Posted: Sun Jul 24, 2005 2:38 am

I have no experience with Dallas Clock chips, but that's what you're looking for. (Anyone willing to chip in?) Some chips, I've read, can have the battery easily replaced and others require replacing the whole thing. (Solding on a motherboard gets even the best solderers a little uneasy--they're too valuable.)

Joined: 02 Oct 2004 Posts: 377 Location: Stuttgart, Germany

I had exactly the same problem. I had an at-compatible computer with a dead dallas 1287 real time clock. That was the reaon i came to ucl a few years back. I got a working 1287 replacement off eBay. And I was lucky enough to know an electronics technician who has been doing soldering for decades and he soldered the whole chip on there for me. I alos trid Puckdropper's suggestion that there might be a battery in the chip, but I was unable to opne it, even with a razor. and I had to be careful, I didn't want to hit the motherboard by accident when tryintg to cut into the dallas chip. there's also an 'a' version of teh chip, DS1287a, that just means it's a year 2000 compilant version of the ds1287.

Guest

a few of there dallas clock modules are socketed
but despite looking like a big rom chip 24-28 pins, there are only 4.
a tv guy should be able to replace it for you.
the battery looks like an asprin near the bottom, one i have has sort of a clear get filling it . it is shaped like a shoebox, turned upside down.
If electroncs parts are obtainable in the uk, you may be in luck

Joined: 02 Oct 2004 Posts: 377 Location: Stuttgart, Germany

I bought a small lot of Dallas chips on eBay a while back. That's also where I got my working replacement battery from. Just be patient, every once in a while they show up for sale there.
If you can tell me the model number of your dallas chip, I might be able to send you one of the ones I got from that auction. I would only charge you for shipping (insurance preferred to make sure it gets there).

Guest

mf_2 wrote:

I bought a small lot of Dallas chips on eBay a while back. That's also where I got my working replacement battery from. Just be patient, every once in a while they show up for sale there.
If you can tell me the model number of your dallas chip, I might be able to send you one of the ones I got from that auction. I would only charge you for shipping (insurance preferred to make sure it gets there).

Many thanks but I'm OK. I already have a number of sources of the Dallas chip. I just needed to know that that was what I was looking for on the board. I can work with this information now. As it stands, a project with an 8086 PC that I thought was dead has just resurrected itself and that takes prority.

Thanks to everyone for the information! Much obliged.