all good advice (bear in mind I'm no expert though).
But what about vinegar and maybe salt to clean the surface of the board? It
eats green oxidation. There must be other chemicals/substances out there that
will consume battery acid and corrosion. Baking soda and or vinegar?
Wes, you can make a new trace if you want to. In my opinion it may make more
sense to solder the trace to it's respective points, and forego epoxying until
later. You may even be able to get away without it. Just to see if it works.
And you can get some thin hookup wire and use that to determine if that's the
problem. Just use a small bit of solder clipped from a roll (I have some very
thin kester no lead solder in my stash), and a not iron to just "tack" it in
place. Heck you could mechanically "short" the 2 points together with an all
metal compass say or a bent up paper clip (no it's not really a short, that's
just a way of saying you're connecting 2 points together with a conductor. Be
careful not to actually short anything).
Keep in mind also that sometimes these pads have an opposing pad on the bottom
of the board. You can use that point, if present, to confirm continuity or lack
thereof.
From: Derek Morton <thes...@comcast.net>
To: vintage-macs@googlegroups.com
Sent: Saturday, August 15, 2015 7:53 AM
Subject: Re: IIcx Motherboard Damaged Traces?
Wesley,
Continuity is the key, if your meter is indicating an open then the traces must
be bad. To verify, I would suggest cleaning the area with isopropyl alcohol
first (99% if you can find it otherwise the highest number you can get). Use
an acid brush
(http://www.homedepot.com/p/Oatey-1-2-in-x-6-in-Acid-Brush-307122/100346943)
which has been trimmed to give you a shorter angled brush head (cut off around
half the length of the brush). This will give you a good vertical scrubber
which won't be overly harsh on the surface and will tolerate the chemical
environment. Scrub firmly, but gently... Too much force can cause damage.
After scrubbing you need to clean up the area before the alcohol dries. The
alcohol (in conjunction with the scrubbing) will dissolve and lift the
contaminates from the board but when it evaporates the contaminates will be
re-deposited on the board. Ideally you should use Kimwipes to clean up the
area, but a thin cotton cloth (old t-shirt perhaps) should work reasonably well.
Verify the continuity (or lack of) once cleaned.
You can fix the problem in a couple different ways. The "proper" way is to
remove and replace the track. This is a moderately difficult task requiring
you to remove the damaged track, cut a new track from copper sheet to replace
the damaged section, epoxy it to the board (feathering in the points where the
new trace meets up with the told trace), solder the ends to re-establish
continuity and then coat with new track to protect it. The MUCH easier option
is to simply use some hook-up wire to bypass the damaged section. You can go
from via/pad/track to via/pad/track, take your pick.
I would advise some caution however. Apple's boards do not seem to tolerate
re-work well. Everything seems to lift from the board with very little heat,
so be careful.
Hope it helps,
Derek
On Aug 14, 2015, at 10:22 PM, Wesley Furr wrote:
> I have a IIcx that got eaten alive by a battery leak. I recently acquired a
> replacement motherboard from someone in unknown condition. It would turn on
> but not do anything. Figured it needed a re-cap, and Charles concurred. I
> spent some time this evening removing the caps (put me down for a fan of the
> "twist" method!) and getting it cleaned up. Everything looks good except for
> two traces around C7. Take a look here:
>
> http://www.megley.com/temp/iicx.jpg
>
> The white square lines at the bottom are where C7 sits. My meter is not
> getting continuity between the upper pad on C7 and the spot just above and to
> the right of it. The other trace that goes from the left of it to above it
> looks bad and I'm not getting continuity there either...but I don't know how
> much of that might just be the crud on those points.
>
> What do the experts think? Likely bad? How does one go about repairing
> those traces if they are bad? Can the "points" (are they "vias"?) be cleaned
> up and soldered to? Any thoughts or suggestions would be appreciated. No
> point in wasting good caps on this board if it's not going to work when I get
> done with it...
>
> Thanks,
>
> Wesley
>
--
--
-----
You received this message because you are a member of the Vintage Macs group.
The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our
netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml
To post to this group, send email to vintage-macs@googlegroups.com
To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/vintage-macs
Support for older Macs: http://lowendmac.com/services/
---
You received this message because you are subscribed to the Google Groups
"Vintage Macs" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to vintage-macs+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
--
--
-----
You received this message because you are a member of the Vintage Macs group.
The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our
netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml
To post to this group, send email to vintage-macs@googlegroups.com
To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/vintage-macs
Support for older Macs: http://lowendmac.com/services/
---
You received this message because you are subscribed to the Google Groups
"Vintage Macs" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to vintage-macs+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
