Emerson 500EC CMOS battery

[Retro4me]

Help,
I am looking for some information on where the CMOS battery might be on this old machine, it is a Emerson 500EC, and 80286 - 16 MHz machine, it is telling me the CMOS battery is low. I have not been able to find a coin cell, a plug in battery, or a soldered in barrel style battery. The only thing that I have found is a Dallas Semiconductor DS1287, which is a real time clock/calender/alarm IC. I do know that it will need to be relaced, as it is old, and will not keep the time.
Is this device also the source of the battery backed CMOS ram?

Thank you for your help,

Retro4Me

[Geek-9pm]

Welcome!
Computer Hope is the number one location for free computer help.
The forum will help everyone with all computer questions.

Locate the data sheet for the Dallas clock. From that a tech can trace whee the cell is located.

[Computer_Commando]

...Dallas Semiconductor DS1287...Is this device also the source of the battery backed CMOS ram?...

Yes, the battery is inside the DS1287.
http://www.mcamafia.de/mcapage0/dsrework.htm

[Salmon Trout]

As this Kiwi says, better to remove the DS1287 from the board (it pulls off)




http://www.classic-computers.org.nz/blog/2009-12-05-repairing-a-dallas-chip-in-a-compaq-slt-286.htm

[Retro4me]

Hello All,
Changing the Dallas Semiconductor DS1287 did not fix the problem, the computer still tells me that the CMOS battery is low, and it will not save the CMOS settings. I still don't see any other place for a cell, so I am at a loss as the where it is. Emerson Radio corporation are the ones that built this computer, but the division that built it is long gone.

Thank you for any additional replies,

Retro4Me

[Geek-9pm]

Are you going to quit? 
Is the Dallas chip in a socket?
Your replacement chip  might  also have a dead battery.

If so, you can put it in a small vise  drill into the upper part and find the pins that connect to the battery. Just like the the photos given above.

Or build your own replacement for the data sheet.

[Retro4me]

I did the modification, and mounted a CR2032 coin cell holder on top of the Dallas1287 (the old one), and it works! The new one that I bought must have a dead battery in it, that's why it didn't work. This particular computer has this chip soldered in, so I had been taking it to work to do the work on it there.

So, now my computer is working, and it even ran windows 3.1 on 4 meg of ram.

Thanks for all your help!

Retro4Me