Slicing open the top of a 48T02 Sun Sparc chip to replace battery is that thing hollow or filled with epoxy?
17 May
2001
17 May
'01
2:55 a.m.
Hi
I am considering slicing open the part epoxyed to the top of a 48T02 chip to
replace or hook up a new 3VDC source. I dont wanna buy a new chip....
My plan is to use a Dremel type cutting wheel and do a "lobotomy" on the
module fitted on top of the chip.
Then, either connect a new 3VDC source to this (2 alkalines in a battery
holder) or simply replace the cells inside.
If the thing (the top module with the batt and osc) is not filled with epoxy
I imagine this can be done...does anybody know if that module is "hollow"
and removing the top will reveal the components inside...??? Or will I just
be cutting through solid plastic/epoxy???
Other method would be to slowly grind top of module until components inside
are revealed...
Alternative method is revealing the wires coming from top part to chip by
digging into epoxy on one side and hooking up there (from sun NVRAM faq)...
Thanks
Claude
17 May
17 May
3:33 a.m.
On Thu, 17 May 2001 10:55:47 -0400 "Claude.W"
<claudew(a)videotron.ca> wrote:
I am considering slicing open the part epoxyed to the
top of a 48T02 chip to
replace or hook up a new 3VDC source. I dont wanna buy a new chip....
I've done this myself...
If the thing (the top module with the batt and osc) is
not filled with epoxy
I imagine this can be done...does anybody know if that module is "hollow"
and removing the top will reveal the components inside...??? Or will I just
be cutting through solid plastic/epoxy???
It's solid epoxy. I don't think it would be practical to
completely expose the components.
Alternative method is revealing the wires coming from
top part to chip by
digging into epoxy on one side and hooking up there (from sun NVRAM faq)...
That's the method I used, just exposing part of the wiring
from battery to chip. It's not deeply buried, and
the FAQ
gives the location at the end opposite to Pin 1. I didn't
even disconnect the old battery, but simply paralleled my
own AA battery holder and fitted two AA batteries.
--
John Honniball
Email: John.Honniball(a)uwe.ac.uk
University of the West of England
6:25 a.m.
Once you have the epoxy portion removed, you can go to work on it with solvents
like Methyl Ethyl Ketone to soften/dissolve the EPOXY.
If it's sufficiently cold, it should pop right off the package to which it's
glued if you attack it with a sharp chisel at the boundary between the package
and the epoxy-potted appendage.
Be sure you consider very carefully and well in advance how you're going to hang
onto the thing once you're ready to do the job. This might require you build a
holding fixture so you won't damage the device. It might not be a bad idea to
consider how you're going to restore the potted portion once you've swapped the
battery. In fact, it might not be a bad idea to make a 2-part sandwich so you
can replace the battery next time as well but without the need for surgery.
Dick
----- Original Message -----
From: "John Honniball" <John.Honniball(a)uwe.ac.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, May 17, 2001 9:33 AM
Subject: Re: Slicing open the top of a 48T02 Sun Sparc chip to replace battery
is that thing hollow or filled with epoxy?
On Thu, 17 May 2001 10:55:47 -0400 "Claude.W"
<claudew(a)videotron.ca> wrote:
I am considering slicing open the part epoxyed to
the top of a 48T02 chip to
replace or hook up a new 3VDC source. I dont wanna buy a new chip....
I've done this myself...
If the thing (the top module with the batt and
osc) is not filled with epoxy
I imagine this can be done...does anybody know if that module is "hollow"
and removing the top will reveal the components inside...??? Or will I just
be cutting through solid plastic/epoxy???
It's solid epoxy. I don't think it would be practical to
completely expose the components.
Alternative method is revealing the wires coming
from top part to chip by
digging into epoxy on one side and hooking up there (from sun NVRAM faq)...
That's the method I used, just exposing part of the wiring
from battery to chip. It's not deeply buried, and the FAQ
gives the location at the end opposite to Pin 1. I didn't
even disconnect the old battery, but simply paralleled my
own AA battery holder and fitted two AA batteries.
--
John Honniball
Email: John.Honniball(a)uwe.ac.uk
University of the West of England
10:52 a.m.
John Honniball wrote:
That's the method I used, just exposing part of the wiring
from battery to chip. It's not deeply buried, and the FAQ
gives the location at the end opposite to Pin 1. I didn't
even disconnect the old battery, but simply paralleled my
own AA battery holder and fitted two AA batteries.
I have used the same method, but used a button style battery and a
holder that I bought at Radio Shack.
--
Doug Carman
pdp11(a)bellsouth.net
1:34 p.m.
New subject: Slicing open the top of a 48T02 Sun Sparc chip to replace battery is that thing hollow or filled with epoxy?
That's a different device than what I thought it was. There are some
interesting little MCU's that have a ceramic package and a plastic potted cap
over the top, containing, among other things, a battery. That's what I believed
you guys were fiddling with.
Has anybody tried one of the DALLAS "smart socket" products with this thingie?
It would seem to me that the smart socket (if that's the one with the battery in
the bottom, would be just the thing to "fix" this sort of battery aging problem
without surgery. Similarly, if one were to pot a couple of batteries into the
bottom of a socket and put a schottky diode between the battery output and the
Vcc pin, it should work fine when Vcc isn't there to keep the IC powered up. It
seems to me that the DALLAS device manages the nWR signal as well, so funny
things don't happen during power-transients.
Dick
----- Original Message -----
From: "Doug Carman" <pdp11(a)bellsouth.net>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, May 17, 2001 4:52 PM
Subject: Re: Slicing open the top of a 48T02 Sun Sparc chip to replace battery
is that thing hollow or filled with epoxy?
John Honniball wrote:
That's the method I used, just exposing part of the wiring
from battery to chip. It's not deeply buried, and the FAQ
gives the location at the end opposite to Pin 1. I didn't
even disconnect the old battery, but simply paralleled my
own AA battery holder and fitted two AA batteries.
I have used the same method, but used a button style battery and a
holder that I bought at Radio Shack.
--
Doug Carman
pdp11(a)bellsouth.net
6:17 a.m.
You might, in fact, find that it's easiest if you chill the part in your freezer
and subsequently use a mallet and chisel to pop off the lid.
Dick
----- Original Message -----
From: "Claude.W" <claudew(a)videotron.ca>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, May 17, 2001 8:55 AM
Subject: Slicing open the top of a 48T02 Sun Sparc chip to replace battery is
that thing hollow or filled with epoxy?
Hi
I am considering slicing open the part epoxyed to the top of a 48T02 chip to
replace or hook up a new 3VDC source. I dont wanna buy a new chip....
My plan is to use a Dremel type cutting wheel and do a "lobotomy" on the
module fitted on top of the chip.
Then, either connect a new 3VDC source to this (2 alkalines in a battery
holder) or simply replace the cells inside.
If the thing (the top module with the batt and osc) is not filled with epoxy
I imagine this can be done...does anybody know if that module is "hollow"
and removing the top will reveal the components inside...??? Or will I just
be cutting through solid plastic/epoxy???
Other method would be to slowly grind top of module until components inside
are revealed...
Alternative method is revealing the wires coming from top part to chip by
digging into epoxy on one side and hooking up there (from sun NVRAM faq)...
Thanks
Claude
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days inactive
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5 comments
4 participants
participants (4)
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claudew＠videotron.ca -
edick＠idcomm.com -
John.Honniball＠uwe.ac.uk -
pdp11＠bellsouth.net