Cmos Battery/Clock

I measured 0.0V between pin 12 and pin 24. FWIW. Mikek

Argh, I think I've found it. Above I listed the WO723Y. This is sideways on the end of the chip. I see here on this application note, application-notes.digchip.com/005/5-9794.pdf "The 6-character encapsulation code (CAPHAT? only; Figure 6) is positioned at the end of the device and is placed perpendicularly to the date code. It summarizes details of the encapsulation process" It tells me, it was manufactured on the 72nd day of 2003. Anyone looking at the application note disagree with my conclusion?

Thanks, Mikek

I would say it is the 33rd week of 2010.

You will not be able to measure the battery, there is an isolation diode (actually a power management chip) that kills the chip select line when Vcc drops below 4.5 volts.

Also, you might wish to install a good quality machined pin socket to make the next change easier.

Does my followup with the application note change your mind?

application-notes.digchip.com/005/5-9794.pdf

I think the manufacture date is 72nd day of 2003.

Mikek

One point, the year is a single digit and 2003 is over 10 years old. That is near if not past the end of its shelf life. I'd say it is more likely the date is 2013 and the app note is out of date, but who can say?

One the other hand, why couldn't this be a 24 pin CAPHAT in figure 5? All the lettering makes sense and it then has a date code of 2010, 33rd work week, much preferable over 2003 (I'm assuming they added a year digit in 2010). Maybe Fig 5 is the date of manufacture of the chip and the 2013 encapsulation code is the date when it was all potted?

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Rick

Absolutely, I told you how last month.

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umop apisdn

Oh, please let us knew how, too!

tnx

Jorgen

You said, "It's a regular 0.3" PDIP CMOS RTC chip potted with a lithium battery, they can be opened and the chip connected to a replacable battery."

I tore up as much of the cover as I could and have not got to the battery. It is fitted between two PCI connectors with very little room to maneuver.

I'm not going to tear up this maybe new? 2003 or 2013 chip just to measure the battery. Thanks, Mikek

On third thought, your Date works and makes more sense. MYS 99 1033 MYS = Malaysia 99 = Tested in Muar 1033 the 10 = 2010, 33 = 33rd week

Where it says, "The 6-character encapsulation code (CAPHAT? only; Figure 6) is positioned at the end of the device and is placed perpendicularly to the date code. It summarizes details of the encapsulation process"

Yep, perpendicular to the date code is WO723Y which as it says, "summarizes details of the encapsulation process"

I now feel comfortable with installing this chip.

Tom, thanks, for your input and forcing me to think, although I thought I did think, but I needed to think some more.

Next question, Why is anyone making this chip anymore? Does anyone still use this on a mother board? Where else might it be used.

Thanks for the idea about the socket. I put the new Real-Time Clock, Lithium cell into the computer with the socket that I installed. When I fired it up, I still get the low cmos battery indication andI can't get out of the bios set up. When I do, it just reboots and tells me to press F1 and I'm back in bios. I'm letting it run for a while, maybe the battery will take a charge, I did set the clock and it runs, but it lost the time when I rebooted. Anything I should do before I order a new battery? Mikek

Maybe the date code is for 2003 after all? Or it is just a bad chip or a board problem. With it running, what is the supply voltage on pin 24?

I have 4.97V on pin 24. I noted, if I turn of the computer for 30 seconds it keeps the time in bios, if I turn it off for 2 minutes it loses the time. This is after a

2-1/2 hr power on time.

Here's some screen shots of the bios I'm working in. I am over my knowledge level here, I suspect I need to tell it to boot on the HD. So far I have just left it in auto, but I see a section where I can pick Hard Drive Type by size etc. see last link showing that window.

If the memory can keep time, I would think I could boot, but lose everything when I shut down. So, something else I need to do? At the least, I think I need to order another Clock/Lithium Battery. What do you think? Thanks, Mikek

It appears that your "nonvolatile" aspect ... isn't. The "chip" is reporting the low battery condition so even if *it* was in error, you'd still be stuck replacing the entire module.

As I said in a previous thread (along with some photos), the battery connection to the "silicon" can be exposed with a Dremel (TmReg). You can then measure the actual cell voltage (with a very high impedance DVM, *not* a generic VOM!).

Once you verify that it is dead/dying, you can clip the connection to the cell and piggyback a CR2032 (or similar). In the past, I've used small (AAA) NiCd's as I had a boatload of them.

You don't need to destroy the chip to expose the battery connection.

Dig up my previous post for URL to similar photos.

I went back and found the link you posted, I don't think my IC is the same as in your link.

I have the cover cut off the top. It exposed two more boxes inside. There is not a dimple in those. This did not come apart easy, I cut the cover and pried off some of it, the rest does not want to come off.

Thanks, Mikek

just drill two small holes to reach the power pins and probe with some fine wire,

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umop apisdn

I only what to come off as just a little bit of a smart ass.

"just drill two small holes" about what size drill bit? How deep do I need to drill?

"to reach the power pins" Does it matter where I drill these "small" holes on this 3/4" x 1-1/4" chip so that I can probe the power pins?

Here's diagram showing where to cut on a DS1287 Clock chip.

I don't know that it is the same chip. it doesn't use all the pins, But I'll grind on the chip I have out and see what I run into.

Mikek

Sorry, my bad.

Try this:

(after verifying that it does, in fact, pertain to the device(s) you have in front of you)

Next question would be, is the Dallas chip built the same way as the ST microelectronics chip? ie. do I grind on pin 16 and 20. I'll give it a try,If I can measure a voltage near 3v, I'm probably OK. Mikek