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“ Dallas Chip Battery Hack ”

Story by Pentium , written 11 years ago 3103 views97 votes
DO NOT TRY THIS AT HOME : Text files and message bases are for INFORMATIONAL PURPOSES ONLY. Do not undertake any project based upon any information obtained from this or any other web site.We are not responsible for, nor do we assume any liability for, damages resulting from the use of any information on this site.
First off, be aware that not many systems these days are fitted with dallas chips however they still exist and wait to show their ugly side.

Anyways, The dallas chip first appeared in the late 80’s as an alternative to having a clock crystal and system battery installed on your motherboard. Instead, a single chip managed the real-time clock (RTC) and at the same time had an integrated clock crystal and onboard battery to keep time and other various things like the time...and configuration settings.

What nobody really thought about was what would happen once the battery died. Well the time has come when the batteries in these chips begin to lose their charge and with it all hell can break loose like your system refusing to start-up properly or computer addresses being hosed (seen in older SUN computers and the Silicon Graphics Indy along with others.)
Now that the chip is dead you have to find a replacement but what’s this? they no longer produce your chip for $5 if at all? well if you are reading this then you are in the right place.

The following information will tell you how to hack and revive your dead dallas chip. One thing to be aware of is that there are many different chips out there and this hack has not been done on every chip out there but in my testing, three different model chips have been revived successfully.
Also be aware that during this egg I used two photographs from other sources. This one and this one came from here and here.
All the other photos were done by me and credit to those other two photos go to their respective websites. I only discovered that this had already been done after I had done it myself.

Now to do this job you need some tools.

-Clean space
-volt meter
-wire cutters
-thin wire (telephone and modchip wires work)
-Soldering iron
-solder for electronics
-Dremel with a disc bit and some sort of boring bit.
-Your chip

First off, let’s locate the battery terminals. Before the battery was encased in an epoxy tomb they bent the chip pins for the battery upwards and into the epoxy where the battery was attached and then encased forever. Also in that epoxy is the crystal. You don’t want to mess with it.

That pic was overkill but it exposes the internal parts. Also note the tons of dust.
The pins for the battery itself are usually marked by a missing pin, three visible pins and then another missing (or two in this case) pin. In all the chips I tested this positioning was the same for all (the battery, not the crystal)

After you have located the probable locations of the battery pins, use the boring bit on the dremel to expose the pins. Once you have exposed them, use the volt meter to check for a voltage. If you get one then you have the right pins. Also remember the polarity of the pins. YOU MUST INSTALL THE NEW BATTERY TE SAME WAY OR IT WILL DO BAD THINGS! SCARY THINGS! JUST REMEMBER THE POLARITY!

Now that you have found the pins and you have noted the polarity, use the boring bit to keep digging. Go from where the pin enters the chip and make your way up to the top of the chip. Don’t go side-to-side or you will take out the crystal. Once you have to really start digging to get to the pin or you hit the battery, stop. You should now have a few millimeters of pin showing.
Next, switch to your disc cutter attachment on the dremel and cut both pins. Do not cut too close to the chip and make it a bitch to do the next steps, I recommend you cut somewhere in the middle of where you just cleared out with the boring attachment. You should hear when the disc is through the pin and it starts to eat into the epoxy. Stop when you hear this.

To be positive that the old battery is no longer attached, use your volt meter and look for a voltage on the chip side of the cut (right where the pins enter the chip). If you don’t get a voltage, you are good but if you did you need to keep cutting those pins.
Next, plug in your iron and while it is warming up snip two small (5cm) lengths of wire. If you can, use black for the - side and red for the + side. Strip both ends on the wires and once the iron is ready, tin it and while the wire is touching the pin it is to be connected to, solder the wire into place being careful to not solder together any adjacent pins.
Don’t forget to solder the red wire to the + pin and the black to the - pin.

Now double check that you did not use too much solder and reconnect the old battery or bridge other pins and also remember that you should be careful when flexing the wires or the soldering joints will fail.
Now most dallas chips use a 3-volt battery, an alternative to the one inside is a standard 3-volt coin cell that is usually found on a motherboard. To connect it to the wires, you can get a special battery holder or you can use some electrical tape to hold the stripped part of the wire to the battery
(Remember that polarity).

^didn’t use red and black wires but remembered that polarity.

Now so long as you have a good battery and you didn’t have too much fun playing with the dremel all you have to do now is reinsert the chip (if it was not soldered to the board) and you should be good (unless you are one of those unlucky people who own an old Sparc Station or Indy, in which case you have to reprogram the chips.)

Currently I have done this to my IBM PS/2 model 25, 30 and 55sx systems as well as my Sparc Station IPC and 1+.
The one in my Onyx has yet to fail but I’m ready.

The chips on my Sun computers are hacked differently, you can
see how to fix them

as well as the info in reprogramming the chip.

Info on reprogramming an Indy can be found here.


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