Dallas module battery replacement...

From: jpero_at_cgocable.net <(jpero_at_cgocable.net)>
Date: Sat Apr 8 12:48:27 2000

> From: Technoid_at_cheta.net
> Date: Sat, 08 Apr 2000 17:15:45 -0400
> To: jpero_at_cgocable.net
> Cc: classiccmp_at_classiccmp.org
> Subject: Re: Dallas module battery replacement...

> Depends on the make how to remake the clock batt. The SG Thompson chip I
> retrofitted a batt onto had the leads on the right side of the chip and
> they were easily exposed with a knife.
>
> The dallas chips are constructed a bit differently with no gap between the
> sram on the bottom and the batt/oscillator in the epoxy 'brick' on top.
> The dallas chips are often 'missing' a few pins. Those pins are likely
> bent upward and are the leads for power, ground and oscillator
> connections.

You forgot few models that left a clear contents pin bent up or cut.

Mostly I deal with are DS1287 and DS12887, DS12887A/B and DS12B887
series. Where does the battery appox located toward pin 1 end or
away?

> The dremel drill will likely clear a path but you are going
> to have to take each model chip and learn how it is constructed to fix it.

I happen to have that tool, but not so fun part is LOT OF ground up
dust. Cutting into PCBs is what I hate, fiberglass gives super fine
glass dust powder.

> It is perfectly ok to use a 'clone' batt to power the sram. I used a
> 4.5volt batt I scrounged from a 286 to power the sg thompson chip while I
> waited for the Dallas to arrive.

>From what I see, Dallas would always use 3V lithium coins. What else
that will give good shelf life and last usually 10 years?

> Still, it is far easier to just replace the thing. I had to hang a batt
> on the old one because it was very difficult to find the correct
> replacement part. I hear they won't really be in the channel til next
> year! I got mine straight from Dallas and they had nearly none. I might
> have gotten thier last DS1642!

You haven't touched the issues: Cost, hard to get dallas and it's
clones on any electron suppliers even JDR (costly). Some boards like
digital boards prefers one and only one brand, one model #, but
usually clone boards and many brands of boards like any compatiable
types of cmos IC.

Wizard
Received on Sat Apr 08 2000 - 12:48:27 BST