[David Farber]

I occasionally see this residue where the components are soldered. Is this
flux? Something else?

http://www.pbase.com/image/83992679

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA

[UCLAN]

David Farber wrote:

I occasionally see this residue where the components are soldered. Is this
flux? Something else?

http://www.pbase.com/image/83992679

Rosin core solder leaves flux if not cleaned. So, yes.

[Arfa Daily]

"David Farber" wrote in message
...
I occasionally see this residue where the components are soldered. Is this
flux? Something else?

http://www.pbase.com/image/83992679

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA



I'm not sure what that is, but it doesn't look like any flux residue that
I've ever seen. The little brownish 'blobs' on the tops of Q200's legs do,
as does the lttle patch at the upper edge of its centre leg. If it is flux
residue, I'm sure that you would agree, as a repairer yourself, that it is
very unusual for it to be white like that, which is why you are asking for
the opinions of others on here, I would guess ? Perhaps solder guru Smitty
could offer an opinion from the production point of view.

Arfa

[Martin Crossley]

Arfa Daily wrote:
"David Farber" wrote in message
...
I occasionally see this residue where the components are soldered.
Is this flux? Something else?

http://www.pbase.com/image/83992679

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA



I'm not sure what that is, but it doesn't look like any flux residue
that I've ever seen. The little brownish 'blobs' on the tops of
Q200's legs do, as does the lttle patch at the upper edge of its
centre leg. If it is flux residue, I'm sure that you would agree, as
a repairer yourself, that it is very unusual for it to be white like
that, which is why you are asking for the opinions of others on here,
I would guess ? Perhaps solder guru Smitty could offer an opinion
from the production point of view.
Arfa

I've seen it before; It's flux residue that has become damp, then dried out
again.
Is there also a touch of rust on the end of the transistor's legs (the
brownish blobs)?
And possibly a bit of corrosion on the edges of the tracks, or just poor
resist?
Yet I can't see any corrosion on the 0R22-resistor, but the solder is a bit
grainy, so it's probably either lead-free or has been damp.
I bet the white deposits will turn back to ordinary flux deposit if heated.
Martin.

[Ross Herbert]

On Fri, 17 Aug 2007 00:29:20 +0100, "Martin Crossley"
wrote:

Arfa Daily wrote:
"David Farber" wrote in message
...
I occasionally see this residue where the components are soldered.
Is this flux? Something else?

http://www.pbase.com/image/83992679

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA



I'm not sure what that is, but it doesn't look like any flux
residue
that I've ever seen. The little brownish 'blobs' on the tops of
Q200's legs do, as does the lttle patch at the upper edge of its
centre leg. If it is flux residue, I'm sure that you would agree,
as
a repairer yourself, that it is very unusual for it to be white
like
that, which is why you are asking for the opinions of others on
here,
I would guess ? Perhaps solder guru Smitty could offer an opinion
from the production point of view.
Arfa

I've seen it before; It's flux residue that has become damp, then
dried out
again.
Is there also a touch of rust on the end of the transistor's legs
(the
brownish blobs)?
And possibly a bit of corrosion on the edges of the tracks, or just
poor
resist?
Yet I can't see any corrosion on the 0R22-resistor, but the solder is
a bit
grainy, so it's probably either lead-free or has been damp.
I bet the white deposits will turn back to ordinary flux deposit if
heated.
Martin.


The "brownish blobs" are not flux or anything else. They are simply
the ends of the cropped component leads. The device was soldered with
long leads and then the leads were cropped.

The white residue could be water soluble flux which has not been
removed after soldering the component.
http://www.kester.com/en-us/document...0(26Jan05).pdf

[Ryan Weihl]

Martin Crossley wrote:

Arfa Daily wrote:
"David Farber" wrote in message
...
I occasionally see this residue where the components are soldered.
Is this flux? Something else?

http://www.pbase.com/image/83992679

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA



I'm not sure what that is, but it doesn't look like any flux residue
that I've ever seen. The little brownish 'blobs' on the tops of
Q200's legs do, as does the lttle patch at the upper edge of its
centre leg. If it is flux residue, I'm sure that you would agree, as
a repairer yourself, that it is very unusual for it to be white like
that, which is why you are asking for the opinions of others on
here, I would guess ? Perhaps solder guru Smitty could offer an
opinion from the production point of view.
Arfa

I've seen it before; It's flux residue that has become damp, then
dried out again. Is there also a touch of rust on the end of the
transistor's legs (the brownish blobs)? And possibly a bit of
corrosion on the edges of the tracks, or just poor resist? Yet I
can't see any corrosion on the 0R22-resistor, but the solder is a bit
grainy, so it's probably either lead-free or has been damp. I bet
the white deposits will turn back to ordinary flux deposit if heated.
Martin.

looks like flux residue. But the boaed has not been washed and dried
properly after soldering process.
rw

--

[Smitty Two]

In article ,
"Arfa Daily" wrote:

"David Farber" wrote in message
...
I occasionally see this residue where the components are soldered. Is this
flux? Something else?

http://www.pbase.com/image/83992679

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA



I'm not sure what that is, but it doesn't look like any flux residue that
I've ever seen. The little brownish 'blobs' on the tops of Q200's legs do,
as does the lttle patch at the upper edge of its centre leg. If it is flux
residue, I'm sure that you would agree, as a repairer yourself, that it is
very unusual for it to be white like that, which is why you are asking for
the opinions of others on here, I would guess ? Perhaps solder guru Smitty
could offer an opinion from the production point of view.

Arfa

Guru? Surely you exaggerate. But that dry, flaky, powdery white stuff
looks exactly like rosin flux residue that's been incompletely cleaned
using a saponifier and hot water. That methodology largely replaced
solvents some time back, as one alternative to water-soluble fluxes.

[Bob AZ]

On Aug 16, 10:52?am, "David Farber" wrote:
I occasionally see this residue where the components are soldered. Is this
flux? Something else?

David

Conformal coating. Probably used for moisture protection among other
things. Like a varnish. Also some coatings were epoxy types.

Bob AZ

[Eeyore]

Ryan Weihl wrote:

looks like flux residue. But the boaed has not been washed and dried
properly after soldering process.

Plenty of solder processes these days do not require washing and cleaning. Most
consumer goods in fact.

Graham

[Eeyore]

Bob AZ wrote:

"David Farber" wrote:
I occasionally see this residue where the components are soldered. Is this
flux? Something else?

David

Conformal coating. Probably used for moisture protection among other
things. Like a varnish. Also some coatings were epoxy types.

It is NOT conformal coating. Besides you'll probably only ever see that on
high-end industrial or military gear.

Graham

[Ross Herbert]

On Fri, 17 Aug 2007 03:20:40 GMT, Ross Herbert
wrote:

SNIP
The white residue could be water soluble flux which has not been
removed after soldering the component.
http://www.kester.com/en-us/document...0(26Jan05).pdf

It seems that the brackets around the date in the link act as a
terminator to the hyperlink underlining so you will have to copy and
paste the full url to get the document.

[Eeyore]

Ross Herbert wrote:

Ross Herbert wrote:

The white residue could be water soluble flux which has not been
removed after soldering the component.
http://www.kester.com/en-us/document...0(26Jan05).pdf

It seems that the brackets around the date in the link act as a
terminator to the hyperlink underlining so you will have to copy and
paste the full url to get the document.

It works for me.

Graham

[JW]

On Fri, 17 Aug 2007 08:43:44 +0100 Eeyore
wrote in Message id:
:



Bob AZ wrote:

"David Farber" wrote:
I occasionally see this residue where the components are soldered. Is this
flux? Something else?

David

Conformal coating. Probably used for moisture protection among other
things. Like a varnish. Also some coatings were epoxy types.

It is NOT conformal coating. Besides you'll probably only ever see that on
high-end industrial or military gear.

Or just about anything marine related.

[Ross Herbert]

On Fri, 17 Aug 2007 10:38:15 +0100, Eeyore
wrote:



Ross Herbert wrote:

Ross Herbert wrote:

The white residue could be water soluble flux which has not been
removed after soldering the component.

http://www.kester.com/en-us/document...0(26Jan05).pdf

It seems that the brackets around the date in the link act as a
terminator to the hyperlink underlining so you will have to copy
and
paste the full url to get the document.

It works for me.

Graham


Thanks Graham. When I paste the url link using Agent the underlining
stops before the opening bracket so I thought I'd better give a
warning.

[Al]

In article ,
"David Farber" wrote:

http://www.pbase.com/image/83992679

It is flux residue. All of the VOCs have been removed and the solids are
left. Not to worry. Not pretty, but, ehhh...

Al

[Allodoxaphobia]

On Fri, 17 Aug 2007 00:29:20 +0100, Martin Crossley wrote:
Arfa Daily wrote:
"David Farber" wrote in message
...
I occasionally see this residue where the components are soldered.
Is this flux? Something else?

http://www.pbase.com/image/83992679

I'm not sure what that is, but it doesn't look like any flux residue
that I've ever seen. The little brownish 'blobs' on the tops of
Q200's legs do, as does the lttle patch at the upper edge of its
centre leg. If it is flux residue, I'm sure that you would agree, as
a repairer yourself, that it is very unusual for it to be white like
that, which is why you are asking for the opinions of others on here,
I would guess ? Perhaps solder guru Smitty could offer an opinion
from the production point of view.

I've seen it before; It's flux residue that has become damp, then dried out
again.
Is there also a touch of rust on the end of the transistor's legs (the
brownish blobs)?
And possibly a bit of corrosion on the edges of the tracks, or just poor
resist?
Yet I can't see any corrosion on the 0R22-resistor, but the solder is a bit
grainy, so it's probably either lead-free or has been damp.
I bet the white deposits will turn back to ordinary flux deposit if heated.

It is not of manufacturing origin.

It looks like a (field? post-inspection?) repair -- the replacement of
"Q200". After soldering, the leads of Q200 have been snipped off with a
pair of flush wire cutters -- leaving a clean exposure of the copper of
the leads.

So, the residue is probably dictated by the brand and the quality of the
solder used in the repair.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
*** Killfiling google posts: http://jonz.net/ng.htm

[Michael A. Terrell]

David Farber wrote:

I occasionally see this residue where the components are soldered. Is this
flux? Something else?

http://www.pbase.com/image/83992679


That is flux residue left after a run through a PC board washer, and
oven dry cycle. I saw it all the time in manufacturing. The ladies that
worked the cleaning room hand cleaned that with IPA and flux brushes, or
with a spray defluxer when they couldn't reach it with a brush.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

[Michael A. Terrell]

Bob AZ wrote:

On Aug 16, 10:52?am, "David Farber" wrote:
I occasionally see this residue where the components are soldered. Is this
flux? Something else?

David

Conformal coating. Probably used for moisture protection among other
things. Like a varnish. Also some coatings were epoxy types.


That isn't conformal coating. It is a poor cleaning after the board
was made. The thinnest flux was washed away, the thickest is still
there. The powder is where the flux was a little too thick to
completely wash away in the automated cleaning process, and there was no
attempt to finish the job.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

[David Farber]

"Eeyore" wrote in message
...


Bob AZ wrote:

"David Farber" wrote:
I occasionally see this residue where the components are soldered. Is
this
flux? Something else?

David

Conformal coating. Probably used for moisture protection among other
things. Like a varnish. Also some coatings were epoxy types.

It is NOT conformal coating. Besides you'll probably only ever see that on
high-end industrial or military gear.

Graham


I should mention that the photograph of the circuit board came out of a high
end Proceed amplifier. These amps costs big bucks and fail frequently. The
company offered no support to the independent guy. The authorized service
place in my area wanted $150 an hour plus parts to repair it. No surprise
that Proceed is out of business now.

The other amp I saw this residue in was an a/v receiver, a Marantz SR-8500.

Thanks for your replies.
--
David Farber
David Farber's Service Center
L.A., CA

[Eeyore]

Allodoxaphobia wrote:

It is not of manufacturing origin.

It looks like a (field? post-inspection?) repair -- the replacement of
"Q200". After soldering, the leads of Q200 have been snipped off with a
pair of flush wire cutters -- leaving a clean exposure of the copper of
the leads.

So, the residue is probably dictated by the brand and the quality of the
solder used in the repair.

That looks possible.

Note the difference in solder finish on those 3 pads compared to the 2 others.

Graham

[Ross Herbert]

On Fri, 17 Aug 2007 09:51:22 -0400, Meat Plow
wrote:

On Fri, 17 Aug 2007 10:46:19 +0000, Ross Herbert wrote:

On Fri, 17 Aug 2007 10:38:15 +0100, Eeyore
wrote:



Ross Herbert wrote:

Ross Herbert wrote:

The white residue could be water soluble flux which has not been
removed after soldering the component.

http://www.kester.com/en-us/document...0(26Jan05).pdf

It seems that the brackets around the date in the link act as a
terminator to the hyperlink underlining so you will have to copy
and
paste the full url to get the document.

It works for me.

Graham


Thanks Graham. When I paste the url link using Agent the
underlining
stops before the opening bracket so I thought I'd better give a
warning.

When I double click the link it is incomplete.

Are you using Agent?

I referred the problem to Agent support and received this reply;

Hello, Ross.

Your problem has been noted to development.

The URL recognition is a RegEx in the agent.ini file, it's the key
"Pattern6". Unfortunately, I don't know RegEx well enough to suggest
a modification myself.


--
Jeffrey Kaplan Agent Support Team www.forteinc.com

[Ross Herbert]

On Fri, 17 Aug 2007 23:19:16 +0100, Eeyore
wrote:



Allodoxaphobia wrote:

It is not of manufacturing origin.

It looks like a (field? post-inspection?) repair -- the replacement
of
"Q200". After soldering, the leads of Q200 have been snipped off
with a
pair of flush wire cutters -- leaving a clean exposure of the
copper of
the leads.

So, the residue is probably dictated by the brand and the quality
of the
solder used in the repair.

That looks possible.

To anyone who knows anything about electronics soldering and or pcb
populating it is very obvious that this IS what happened.

[Ross Herbert]

On Fri, 17 Aug 2007 11:41:11 -0400, "Michael A. Terrell"
wrote:

David Farber wrote:

I occasionally see this residue where the components are soldered.
Is this
flux? Something else?

http://www.pbase.com/image/83992679


That is flux residue left after a run through a PC board washer, and
oven dry cycle.

Not in this case it isn't. This is the result of failing to clean the
flux away at all after a manual part placement and soldering
procedure. Such instances may occur when an OEM does not trust that
reflow or wave soldering will be ultra reliable where heavy component
leads are involved. The reflow time has to be adequate to ensure
proper wetting of the heavy leads but where other very small componets
may be damaged by heat this is not recommended. The reflow time is
always set to ensure the most sensitive components will not be damaged
by heat and this may require that heavy leaded components are fitted
manually afterwards.

The result of inadequate cleaning after finished board manufacture is
usually a much lighter white ring or anulus of residue, nothing as
thick or heavy as in the picture.

This is more like what you are talking about
http://www.residues.com/pdf/white_residue1.pdf

[Smitty Two]

In article ,
Ross Herbert wrote:

On Fri, 17 Aug 2007 11:41:11 -0400, "Michael A. Terrell"
wrote:

David Farber wrote:

I occasionally see this residue where the components are soldered.
Is this
flux? Something else?

http://www.pbase.com/image/83992679


That is flux residue left after a run through a PC board washer, and
oven dry cycle.

Not in this case it isn't. This is the result of failing to clean the
flux away at all after a manual part placement and soldering
procedure. Such instances may occur when an OEM does not trust that
reflow or wave soldering will be ultra reliable where heavy component
leads are involved. The reflow time has to be adequate to ensure
proper wetting of the heavy leads but where other very small componets
may be damaged by heat this is not recommended. The reflow time is
always set to ensure the most sensitive components will not be damaged
by heat and this may require that heavy leaded components are fitted
manually afterwards.

The result of inadequate cleaning after finished board manufacture is
usually a much lighter white ring or anulus of residue, nothing as
thick or heavy as in the picture.

This is more like what you are talking about
http://www.residues.com/pdf/white_residue1.pdf

Ross, why do you bring up reflowing? Wave soldering, sure, but this
ain't no SMT board. And, a small transistor like that hardly qualifies
as "heavy" leads. However, on another look, I agree that it was added by
hand - but only because it's on the far side of the board.

Still, flux that is "not cleaned away at all" bears little resemblance
to the picture.

Again, I agree with those who say it's incompletely cleaned flux residue
from an automated cleaning system.

[Michael A. Terrell]

Ross Herbert wrote:

Not in this case it isn't. This is the result of failing to clean the
flux away at all after a manual part placement and soldering
procedure. Such instances may occur when an OEM does not trust that
reflow or wave soldering will be ultra reliable where heavy component
leads are involved. The reflow time has to be adequate to ensure
proper wetting of the heavy leads but where other very small componets
may be damaged by heat this is not recommended. The reflow time is
always set to ensure the most sensitive components will not be damaged
by heat and this may require that heavy leaded components are fitted
manually afterwards.

The result of inadequate cleaning after finished board manufacture is
usually a much lighter white ring or anulus of residue, nothing as
thick or heavy as in the picture.

This is more like what you are talking about
http://www.residues.com/pdf/white_residue1.pdf


Ross, we manufactured both surface mount and through hole boards,
plus some items like connectors were hand soldered on our surface mount
PC boards. We had a VERY high standard of cleaning, because most of our
equipment was sold to the aerospace industry. I've seen probably every
possible defect in a new PC board, including a batch we received with a
missing internal power plane. I have seen this exact type of residue on
boards that just came out of the dryer, after being washed.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

[Ross Herbert]

On Fri, 17 Aug 2007 21:09:27 -0700, Smitty Two
wrote:

In article ,
Ross Herbert wrote:

On Fri, 17 Aug 2007 11:41:11 -0400, "Michael A. Terrell"
wrote:

David Farber wrote:

I occasionally see this residue where the components are
soldered.
Is this
flux? Something else?

http://www.pbase.com/image/83992679


That is flux residue left after a run through a PC board washer,
and
oven dry cycle.

Not in this case it isn't. This is the result of failing to clean
the
flux away at all after a manual part placement and soldering
procedure. Such instances may occur when an OEM does not trust that
reflow or wave soldering will be ultra reliable where heavy
component
leads are involved. The reflow time has to be adequate to ensure
proper wetting of the heavy leads but where other very small
componets
may be damaged by heat this is not recommended. The reflow time is
always set to ensure the most sensitive components will not be
damaged
by heat and this may require that heavy leaded components are
fitted
manually afterwards.

The result of inadequate cleaning after finished board manufacture
is
usually a much lighter white ring or anulus of residue, nothing as
thick or heavy as in the picture.

This is more like what you are talking about
http://www.residues.com/pdf/white_residue1.pdf

Ross, why do you bring up reflowing? Wave soldering, sure, but this
ain't no SMT board. And, a small transistor like that hardly
qualifies
as "heavy" leads. However, on another look, I agree that it was added
by
hand - but only because it's on the far side of the board.

Still, flux that is "not cleaned away at all" bears little
resemblance
to the picture.

Again, I agree with those who say it's incompletely cleaned flux
residue
from an automated cleaning system.

[Ross Herbert]

On Fri, 17 Aug 2007 21:09:27 -0700, Smitty Two
wrote:

In article ,
Ross Herbert wrote:

On Fri, 17 Aug 2007 11:41:11 -0400, "Michael A. Terrell"
wrote:

David Farber wrote:

I occasionally see this residue where the components are
soldered.
Is this
flux? Something else?

http://www.pbase.com/image/83992679


That is flux residue left after a run through a PC board washer,
and
oven dry cycle.

Not in this case it isn't. This is the result of failing to clean
the
flux away at all after a manual part placement and soldering
procedure. Such instances may occur when an OEM does not trust that
reflow or wave soldering will be ultra reliable where heavy
component
leads are involved. The reflow time has to be adequate to ensure
proper wetting of the heavy leads but where other very small
componets
may be damaged by heat this is not recommended. The reflow time is
always set to ensure the most sensitive components will not be
damaged
by heat and this may require that heavy leaded components are
fitted
manually afterwards.

The result of inadequate cleaning after finished board manufacture
is
usually a much lighter white ring or anulus of residue, nothing as
thick or heavy as in the picture.

This is more like what you are talking about
http://www.residues.com/pdf/white_residue1.pdf

Ross, why do you bring up reflowing? Wave soldering, sure, but this
ain't no SMT board. And, a small transistor like that hardly
qualifies
as "heavy" leads. However, on another look, I agree that it was added
by
hand - but only because it's on the far side of the board.

You are right with regard to reflow - my mistake for mentioning it.
However, with regard to the component and reasons why it would have
been manually fitted, I was just giveing an example. It wasn't meant
to be the ONLY reason why the component might have been added manually
yo this particular board although I admit it would have been wise to
stick to this point.

Still, flux that is "not cleaned away at all" bears little
resemblance
to the picture.

In my experience it is. It is obvious that there has been some
"scratching around" in the residue which has removed some of it
(perhaps by the OP). In its natural state it would have been far more
regular and quite thick as it appears to me. I would wager that after
this component was manually soldered the operator didn't even so much
as wave cleaning fluid over it let alone attack it with a brush. After
adding a single component I doubt too many manufacturers would put the
whole board through a clean and dry cycle since it takes a lot longer
than doing it by hand immediately after soldering.

Again, I agree with those who say it's incompletely cleaned flux
residue
from an automated cleaning system.

Incompletely cleaned flux in my experience has always been more in
keeping with this effect
http://www.residues.com/pdf/white_residue1.pdf but a water soluble
flux applied by hand and which has not been cleaned at all is more
akin to the OP's situation.

[Eeyore]

Smitty Two wrote:

Ross, why do you bring up reflowing? Wave soldering, sure, but this
ain't no SMT board. And, a small transistor like that hardly qualifies
as "heavy" leads.

I have seen 'cold joint' issues with TO-220 devices.

Graham

[Michael A. Terrell]

Eeyore wrote:

Smitty Two wrote:

Ross, why do you bring up reflowing? Wave soldering, sure, but this
ain't no SMT board. And, a small transistor like that hardly qualifies
as "heavy" leads.

I have seen 'cold joint' issues with TO-220 devices.


Sure, from crappy board houses.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida