On 01/22/2017 12:57 PM, allison wrote:
I don't know about most people but this solution has been around for
decades.
I locate the battery on the failed part with a small magnet, then grind the
epoxy down to it then pick it out with a sharp pointed tool. Once I expose
the connection point I older two wires then epoxy a small coin-cell holder
in that spot and it s done. I've done this more times than I care to count
and its effective and the replacement battery some over 10 years old
now have not failed. But just in case I have a bag of NOS replacements
(and pulls from socketed boards) all with dead batteries from age. There
is no magic to this.
Most of these Dallas clock/RAM chips can be popped open VERY
easily! Take an Xacto knife and pick around the edges on
the pin side, and usually the plastic cover will pop free
from the epoxy fill. Then, the cover can be lifted, and you
will find a standard 28-pin (I think) DIP chip with a button
cell wired onto the top of the chip. The ones I've opened
were not totally filled with epoxy, the IC package acted as
a sort of dam to prevent the cover from completely filling
with the stuff.
Jon
