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Michael A. Terrell Michael A. Terrell is offline
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Default Gel on finished PCB?


Braunbear wrote:

On Jul 10, 12:06 pm, Smitty Two wrote:
In article ,
Rich Webb wrote:









On Sun, 10 Jul 2011 05:50:34 -0700 (PDT), Braunbear
wrote:


Hi,
I am going to be vague for this first post.Please excuse me.


A number of folks have very recently purchased defective AV receivers
from a certain well known manufacturer. Since the manufacturer does
not publicly disclose the cause of the symptoms owners are
experiencing, much speculation has occurred as to the cause. The
speculation I refer to is on a thread in a forum for AV enthusiasts.
Since the repair involves a 40 pin ribbon cable and its associated
connectors, one poster claims to have inside information as to the
cause of the failure of these components. His claim is that there was
an acidic gel applied to the PCB and connectors that corrodes the
cable and connectors. Not knowing of any gel that could be left on a
finished product's PCBs, especially in the area of a connector, I
question this claim. So, my question is, does anyone have any
explanation as to how or why or what this gel might be? And is it a
feasible claim that there was such a gel? To me, the claim is
extraordinary and leaves me with more questions than answers.


Thanx in advance. Any help would be much appreciated.


Flux residue?


Could be, water-soluble flux is corrosive, and many manufacturers
switched to it when CFCs were banned. Board populated, soldered, washed,
then connectors added by hand and not washed.


Thanx everyone for the quick responses. I appreciate the effort. Well,
i learned that there is no gel, other than possible flux residue. I
opened my unit and discovered no gel or residue, but I do have the
symptoms of the defect. I just wish the manufacturer would be more
forthcoming and let us know what went wrong as the symptoms are
intermittent and the fix did not work for me. My cable and connectors
were replaced. Not to mention, this happened to so many units across
the entire model lineup that its hard to imagine they were all not
washed properly. Thanx again.



Actually, they may have missed that step on the entire product run,
which is why they don't want to say anything. Cleaning a PCB cost
money, and slows production. The bean counters cut every corner they
can, and some they can't. It sounds like it's time for a 'Class Action
Lawsuit'.


--
It's easy to think outside the box, when you have a cutting torch.