On 11/27/2018 03:34 PM, Jeffrey S. Worley via cctalk wrote:
When I bought that Sparcstation 4/330 at Computer
Parts Barn, the 48T02
was one of the problems with it. The chip looks like a piggieback rom
encapsulated in epoxy.
I was not reinventing the wheel at the time, I think, because it was
the year 2000 or so, but I looked for a replacement and found them hard
to come by. So, knowing the battery was most likely the fault, I went
about fixing that bit.
The battery accounts for the high profile. You do not have to cut the
entire doggone batter off, the terminals are at one side, iirc, the
right-hand side if the notch is to your left. It is high on the epoxy,
so all you need do is cut down an eighth of an inch in that region,
just shave that top edge until you expose the battery terminals. I
forget how I determined the polarity of them, perhaps I plugged it into
the board after and tested the terminals for power, but all you do once
you've exposed the terminals is solder a power and a ground wire to
them and attach a 3volt battery. I used a pack with two AA's, in a
case so they are user-replaceable. They are probably STILL keeping
time in that machine, wherever DHS took it and my MEGA ST4 and DG
MV4000/dc... That's another story.
So refurbishing these chips is a cakewalk, takes 15 minutes (the second
time 'round), and will work til' doomsday.
Best regards,
Jeff
I take a very simple approach:
All the ones I've ever purchased were bad out of the box (NOS parts), so
much for china but they can be repaired too.
After removing it from the board...
I use a small magnet to locate the battery.? I use a sharp wood chisel
about .25 wide and carve the plastic down
to the battery then get under one edge.?? Once metal is visible I clear
the plastic and pop it out.? The wires then
are easy to locate and I mount using Hot-melt glue a new holder for the
very common 2032.??? Never had to
replace one of those and a few are pushing more than 12years.? The whole
mess takes less than a few minutes
to do where access the board and getting it off the board are the bigger
part of it.? Since I have a few NOS
(but dead) parts plus pulls from old CPU cards I rarely worry if the
existing one gets damaged as I have spares.
To me its not a big deal.
Allison