Obviously I've come acros melting/burning, starting from bad connection
arcing , but not this amount of damage, so am requesting other opinions.

A superfluity of mains fuses all ok, on 240V UK mains, 5 amp in plug, 4 amp
chassis mounted and internal 5 amp all in series. Mains transformer seems
right sort of primary and secondary resistance. All other internal fuses ok
and no other visually obvious problems.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC, melting
of the plastic of the IEC above the burning and even the linecord plug
surrounding the L pin melting where heat conducted through the pin
presumably. Remainder of IEC receptacle distorted from heat but holding
together.
The N pin soldering at the pcb is bad, but has continuity, I assume
pre-existing rather than from heat damage as 3/4 inch from the main L
arcing, so temp would not have reached solder melt point on the N pin. I
assume the L pin solder was worse and initial cause of arcing. Amp was just
idling , with no sound throughput, is that why so much damage as only tens
of mA passing in the arcs. ? If 0.5 amp or more, then the damage would have
been more extreme , but shorter duration, before total break in pcb track or
solder joint meant a fuse action in effect, before greater heat damage could
take effect. The remnant pcb charring is not obviously conductive (30 M ohm
DVM)

Incidently the earth pin soldering although smoke stained looks fine,
coincidence? or passing of electricity have an initiation effect on good
solder to become bad or does it require porous solder or something
inherently bad with it for a heating effect to come into play, long before
any full arcing?


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

fuses are 5A mains,2AT,5AQ
after cleaning away as much grime as possible , any suggestions for
disguising/absorbing the remanant pong ?

N_Cook wrote:

Obviously I've come acros melting/burning, starting from bad connection
arcing , but not this amount of damage, so am requesting other opinions.

A superfluity of mains fuses all ok, on 240V UK mains, 5 amp in plug, 4 amp
chassis mounted and internal 5 amp all in series. Mains transformer seems
right sort of primary and secondary resistance. All other internal fuses ok
and no other visually obvious problems.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC, melting
of the plastic of the IEC above the burning and even the linecord plug
surrounding the L pin melting where heat conducted through the pin
presumably. Remainder of IEC receptacle distorted from heat but holding
together.
The N pin soldering at the pcb is bad, but has continuity, I assume
pre-existing rather than from heat damage as 3/4 inch from the main L
arcing, so temp would not have reached solder melt point on the N pin. I
assume the L pin solder was worse and initial cause of arcing. Amp was just
idling , with no sound throughput, is that why so much damage as only tens
of mA passing in the arcs. ? If 0.5 amp or more, then the damage would have
been more extreme , but shorter duration, before total break in pcb track or
solder joint meant a fuse action in effect, before greater heat damage could
take effect. The remnant pcb charring is not obviously conductive (30 M ohm
DVM)

Incidently the earth pin soldering although smoke stained looks fine,
coincidence? or passing of electricity have an initiation effect on good
solder to become bad or does it require porous solder or something
inherently bad with it for a heating effect to come into play, long before
any full arcing?

Has someone spilled liquid into it?

If you measured the resistance of the charring with low voltage, you
might have had a false high reading; with 240v you could find that it
flashes over or sputters badly.

What would the normal running current and the maximum fault current from
a shorted transformer secondary have been? A bad joint of 5k-ohms in a
circuit carrying 20 mA will develop 2 watts, which is enough to char a
PCB.


I have come across some connector pairs purporting to be IEC-compliant,
where the pins and the socket connections hardly touched. I submitted
them to Trading Standards and was told that both halves did comply with
the specification - so you might have come across a similar problem to
that; and the fault may not be in the soldering.



--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Adrian Tuddenham wrote in message
valid.invalid...
N_Cook wrote:

Obviously I've come acros melting/burning, starting from bad connection
arcing , but not this amount of damage, so am requesting other opinions.

A superfluity of mains fuses all ok, on 240V UK mains, 5 amp in plug, 4
amp
chassis mounted and internal 5 amp all in series. Mains transformer
seems
right sort of primary and secondary resistance. All other internal fuses
ok
and no other visually obvious problems.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord plug
surrounding the L pin melting where heat conducted through the pin
presumably. Remainder of IEC receptacle distorted from heat but holding
together.
The N pin soldering at the pcb is bad, but has continuity, I assume
pre-existing rather than from heat damage as 3/4 inch from the main L
arcing, so temp would not have reached solder melt point on the N pin. I
assume the L pin solder was worse and initial cause of arcing. Amp was
just
idling , with no sound throughput, is that why so much damage as only
tens
of mA passing in the arcs. ? If 0.5 amp or more, then the damage would
have
been more extreme , but shorter duration, before total break in pcb
track or
solder joint meant a fuse action in effect, before greater heat damage
could
take effect. The remnant pcb charring is not obviously conductive (30 M
ohm
DVM)

Incidently the earth pin soldering although smoke stained looks fine,
coincidence? or passing of electricity have an initiation effect on good
solder to become bad or does it require porous solder or something
inherently bad with it for a heating effect to come into play, long
before
any full arcing?

Has someone spilled liquid into it?

If you measured the resistance of the charring with low voltage, you
might have had a false high reading; with 240v you could find that it
flashes over or sputters badly.

What would the normal running current and the maximum fault current from
a shorted transformer secondary have been? A bad joint of 5k-ohms in a
circuit carrying 20 mA will develop 2 watts, which is enough to char a
PCB.


I have come across some connector pairs purporting to be IEC-compliant,
where the pins and the socket connections hardly touched. I submitted
them to Trading Standards and was told that both halves did comply with
the specification - so you might have come across a similar problem to
that; and the fault may not be in the soldering.



--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk



Where the pins of the IEC chassis part go through the plastic there is no
melting or burning but the linecord plug (softer plastic) shows signs of
melting around the line pin , no burning. So the initial problem not
mis-mating of IEC pins. Downstream problems , transformer, ps etc is
possible I suppose , no blown fuses though.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On May 21, 2:59*am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad connection
arcing , but not this amount of damage, so am requesting other opinions.


Burning right thru the pcb for 1/2 inch around the L pin of the IEC, melting
of the plastic of the IEC above the burning and even the linecord plug

Yep, ring crack around a power solder connection, generates lots of
heat.
If you can clean away the char, do it (I've used glass bead blasting
to good effect). Paint the affected region with Q-dope/styrene
varnish/corona dope
when cleaning/soldering/flux cleaning is done.

Replace any AC fittings that look damaged, of course.

N_Cook wrote:

Adrian Tuddenham wrote in message
valid.invalid...
N_Cook wrote:

Obviously I've come acros melting/burning, starting from bad connection
arcing , but not this amount of damage, so am requesting other opinions.

A superfluity of mains fuses all ok, on 240V UK mains, 5 amp in plug, 4
amp
chassis mounted and internal 5 amp all in series. Mains transformer
seems
right sort of primary and secondary resistance. All other internal fuses
ok
and no other visually obvious problems.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord plug
surrounding the L pin melting where heat conducted through the pin
presumably. Remainder of IEC receptacle distorted from heat but holding
together.
[...]

I have come across some connector pairs purporting to be IEC-compliant,
where the pins and the socket connections hardly touched. I submitted
them to Trading Standards and was told that both halves did comply with
the specification - so you might have come across a similar problem to
that; and the fault may not be in the soldering.



Where the pins of the IEC chassis part go through the plastic there is no
melting or burning but the linecord plug (softer plastic) shows signs of
melting around the line pin , no burning.

Some of those IEC chassis connectors are almost indestructible. I have
tried to melt one of the pins out of one with a soldering iron and it
simply would not move. I had to tear the rivetted tag off the back with
a vice, then file down the remains of the pin and punch it out.

I can quite believe that the items each side could be damaged by heat
but the connector in the middle would show no signs of burning.

So the initial problem not
mis-mating of IEC pins. Downstream problems , transformer, ps etc is
possible I suppose , no blown fuses though.

If the direct cause of the heat was a high resistance joint, you
wouldn't expect a blown fuse. A shorted secondary on a small
transformer wouldn't necessarily blow the fuse either.

It has occurred to me that if a solder joint had gone high resistance,
the increase in temperature would either melt it back together or blow
it open before the board became damaged. I still think a poor
plug/socket connection is a likely cause.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Adrian Tuddenham wrote in message
valid.invalid...
N_Cook wrote:

Adrian Tuddenham wrote in message
valid.invalid...
N_Cook wrote:

Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.

A superfluity of mains fuses all ok, on 240V UK mains, 5 amp in
plug, 4
amp
chassis mounted and internal 5 amp all in series. Mains transformer
seems
right sort of primary and secondary resistance. All other internal
fuses
ok
and no other visually obvious problems.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug
surrounding the L pin melting where heat conducted through the pin
presumably. Remainder of IEC receptacle distorted from heat but
holding
together.
[...]

I have come across some connector pairs purporting to be
IEC-compliant,
where the pins and the socket connections hardly touched. I submitted
them to Trading Standards and was told that both halves did comply
with
the specification - so you might have come across a similar problem to
that; and the fault may not be in the soldering.



Where the pins of the IEC chassis part go through the plastic there is
no
melting or burning but the linecord plug (softer plastic) shows signs of
melting around the line pin , no burning.

Some of those IEC chassis connectors are almost indestructible. I have
tried to melt one of the pins out of one with a soldering iron and it
simply would not move. I had to tear the rivetted tag off the back with
a vice, then file down the remains of the pin and punch it out.

I can quite believe that the items each side could be damaged by heat
but the connector in the middle would show no signs of burning.

So the initial problem not
mis-mating of IEC pins. Downstream problems , transformer, ps etc is
possible I suppose , no blown fuses though.

If the direct cause of the heat was a high resistance joint, you
wouldn't expect a blown fuse. A shorted secondary on a small
transformer wouldn't necessarily blow the fuse either.

It has occurred to me that if a solder joint had gone high resistance,
the increase in temperature would either melt it back together or blow
it open before the board became damaged. I still think a poor
plug/socket connection is a likely cause.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

The half inch radius destruction was total , burning down to glass mat , the
thickness of the board. I just cannot see that happening due to an arcing
contact inside the mated plug and socket and the heat conducted through an
inch or so of metal conductor , with only marginal melting to the line cord
plug.

Without carving into the line plug I cannot see the surface of the female
part but the male pins in the chassis section show no pitting or sign of
arcing.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Another maybe relevant factor. The IEC socket was rivetted to the pcb and
very firm but the section that is chassis mounted had much smaller diameter
screws than I would normally expect. Although star washers under the nuts
they undid easily. Maybe that due to the heating but also could be due to
normal inserting of cord into socket straining the pcb solder connections
over years of use/stowage. Would also explain why no obvious bad solder on
the ground pin as that is mechanically more remote by another half inch of
conductor compared to the active conductor lengths.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N_Cook wrote:

Burning right thru the pcb for 1/2 inch around the L pin of the IEC, melting
of the plastic of the IEC above the burning and even the linecord plug
surrounding the L pin melting where heat conducted through the pin
presumably.

Indicates vast overcurrent.

Did someone put aluminium foil in the plugtop fuse ? Typical musician practice.

Graham

Adrian Tuddenham wrote:

Has someone spilled liquid into it?

If built to BSEN60065 properly it wouldn't matter. Fault currents should be dealt
with by blowing fuses or adequate copper foil thickness / area to withstand the
current.

I'll bet some clot replaced a fuse with some ali foil.

Graham

whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad connection
arcing , but not this amount of damage, so am requesting other opinions.

Burning right thru the pcb for 1/2 inch around the L pin of the IEC, melting
of the plastic of the IEC above the burning and even the linecord plug

Yep, ring crack around a power solder connection, generates lots of
heat.

Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And turns to dust.
Adding a little copper doesn't stop it but slows it some but not enough.

The EU Commission should be strung by their necks from lamp-posts for being a
bunch of technically ignorant ****s. Why do they think lead was used in solder in
the first place ? For fun ?

Graham

Adrian Tuddenham wrote:

I still think a poor plug/socket connection is a likely cause.

Loose contact pressure high resistance joint. I've heard of it and had it
reported to me but never seen it personally.

It happens when cheapskate bands treat their kit like **** and don't look after
cables and their own personal safety.

Graham

N_Cook wrote:

Without carving into the line plug I cannot see the surface of the female
part but the male pins in the chassis section show no pitting or sign of
arcing.

If you're reading my posts ( which I doubt since you ask so many daft questions
the answers to which that you ought to *know ) do these thing.

Insert the apparently undamaged part into a new mating half. Does it hold firm ?

Apply a serious current through each contact and measure the volt drop. That'll
tell you the contact resistance from which much can be deduced.

And when bands bring in gear with 'tatty' mains leads, replace them and destroy
the defective one ( hand it back in a bag). They cost bugger all and could save
a life.

Also check the plugtop fuse rating fitted. It's easy to put a 13A fuse in the
plug of a 5A lead. And VERY stupid.

Graham

N_Cook wrote:

Another maybe relevant factor. The IEC socket was rivetted to the pcb and
very firm but the section that is chassis mounted had much smaller diameter
screws than I would normally expect. Although star washers under the nuts
they undid easily. Maybe that due to the heating but also could be due to
normal inserting of cord into socket straining the pcb solder connections
over years of use/stowage. Would also explain why no obvious bad solder on
the ground pin as that is mechanically more remote by another half inch of
conductor compared to the active conductor lengths.

Look for the basics instead of pontificating. That's where it'll be. Getting on
for 40 yrs experience tells me that.

Graham

"Eeyore" wrote in message
...


whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad connection
arcing , but not this amount of damage, so am requesting other
opinions.

Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord plug

Yep, ring crack around a power solder connection, generates lots of
heat.

Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And turns
to dust.
Adding a little copper doesn't stop it but slows it some but not enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used in
solder in
the first place ? For fun ?

Graham


Just what I've been saying since they first mandated the hateful stuff ...

Arfa

Arfa Daily wrote in message
...

"Eeyore" wrote in message
...


whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.

Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug

Yep, ring crack around a power solder connection, generates lots of
heat.

Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used in
solder in
the first place ? For fun ?

Graham


Just what I've been saying since they first mandated the hateful stuff ...

Arfa



This is a 1998 amplifier, made in China so conventional solder ? does not
look "volcanic" or tin-pesty dusty grey solder points on the boards.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N_Cook wrote:
Arfa Daily wrote in message
...
"Eeyore" wrote in message
...

whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug
Yep, ring crack around a power solder connection, generates lots of
heat.
Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used in
solder in
the first place ? For fun ?

Graham

Just what I've been saying since they first mandated the hateful stuff ...

Arfa



This is a 1998 amplifier, made in China so conventional solder ? does not
look "volcanic" or tin-pesty dusty grey solder points on the boards.



It probly started off as a hairline crack around one of the soldered
joins, caused by repeated connecting and disconnecting. It started
'fizzling', no one noticed (or cared) until the amp failed to work by
which time there was a socking great hole in the board and a nasty
smell. It`a amazing how long a lot of musicians will put up with faulty
gear, prefering to ignore problems till the item stops working.

Doesn't really need a post mortem.

Ron(UK)

Ron wrote in message
...
N_Cook wrote:
Arfa Daily wrote in message
...
"Eeyore" wrote in message
...

whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug
Yep, ring crack around a power solder connection, generates lots of
heat.
Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not
enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used
in
solder in
the first place ? For fun ?

Graham

Just what I've been saying since they first mandated the hateful stuff
....

Arfa



This is a 1998 amplifier, made in China so conventional solder ? does
not
look "volcanic" or tin-pesty dusty grey solder points on the boards.



It probly started off as a hairline crack around one of the soldered
joins, caused by repeated connecting and disconnecting. It started
'fizzling', no one noticed (or cared) until the amp failed to work by
which time there was a socking great hole in the board and a nasty
smell. It`a amazing how long a lot of musicians will put up with faulty
gear, prefering to ignore problems till the item stops working.

Doesn't really need a post mortem.

Ron(UK)


I agree that is the normal etiology and pathology, carrying on the
medico-speak. But this was a socking great burnt patch and billowing smoke
out of the 1/4 inch socket holes, that developed after sound check and
before use proper. Agreed there could have been long term, unnoticed, minor
fizzing but I've never seen this sort of damage in this sort of mains power
line circumstance.

N_Cook wrote:
Ron wrote in message
...
N_Cook wrote:
Arfa Daily wrote in message
...
"Eeyore" wrote in message
...
whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug
Yep, ring crack around a power solder connection, generates lots of
heat.
Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not
enough.
The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used
in
solder in
the first place ? For fun ?

Graham

Just what I've been saying since they first mandated the hateful stuff
...
Arfa


This is a 1998 amplifier, made in China so conventional solder ? does
not
look "volcanic" or tin-pesty dusty grey solder points on the boards.


It probly started off as a hairline crack around one of the soldered
joins, caused by repeated connecting and disconnecting. It started
'fizzling', no one noticed (or cared) until the amp failed to work by
which time there was a socking great hole in the board and a nasty
smell. It`a amazing how long a lot of musicians will put up with faulty
gear, prefering to ignore problems till the item stops working.

Doesn't really need a post mortem.

Ron(UK)


I agree that is the normal etiology and pathology, carrying on the
medico-speak. But this was a socking great burnt patch and billowing smoke
out of the 1/4 inch socket holes, that developed after sound check and
before use proper. Agreed there could have been long term, unnoticed, minor
fizzing but I've never seen this sort of damage in this sort of mains power
line circumstance.

I`m surprised, it`s a pretty common failure mode.
Bear in mind that the point of arcing usually comes before the
equipments internal mains fuse, but after the fuse in the plug top,
which is more often than not rated at 13amps.
Once the board starts to carbonise quite a large current can flow, and
the current is only flowing between two points it was intented to flow
anyway - at least initially. It doesnt take long for it to burn a hole
in a board.

Eeyore wrote:


The EU Commission should be strung by their necks from lamp-posts for being a
bunch of technically ignorant ****s. Why do they think lead was used in solder
in the first place ? For fun ?

In the past I have many times agreed with your facts, but I have often
disagreed with your way of expressing them. On this occasion I am with
you all the way.

Let's hope the first aeroplane to crash because of lead-free solder has
only Brussels diplomats and anti-lead campaigners on board.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

"Adrian Tuddenham" wrote in message
alid.invalid...
Eeyore wrote:


The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used in
solder
in the first place ? For fun ?

In the past I have many times agreed with your facts, but I have often
disagreed with your way of expressing them. On this occasion I am with
you all the way.

Let's hope the first aeroplane to crash because of lead-free solder has
only Brussels diplomats and anti-lead campaigners on board.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

As far as I know, at this point in time, the avionics industry still has an
exemption from having to use the stuff. Now I wonder why that could be ... ?

Arfa

N_Cook wrote:

Do you know the most authorative source/group, academic or industry
expert/s, on tin-pest, lead-free solder, in-service degradation of solder in
connjunction with temperature and vibration. ie those issues, as distinct
from tin whiskers aspect that seems to have more coverage.

ERA, I thin, did a report for the EU which smelt of trying to brush the evidence
under the carpet.

Graham

Arfa Daily wrote:

To N.Cook The place that I got my research material from was Tin Technology
Ltd with a website of www.lead-free.org The person that I spoke to at that
body, pointed me to www.dti.gov.uk/sustainability/weee/index.htm I also
spoke to a Dr Goodman at ERAT Technology Ltd

That's Paul Goodman at ERA Technology. The final report is here.
http://ec.europa.eu/environment/wast...nal_report.pdf

There was a simpler 30 or so page interim report I've mislaid which definitely
showed indications of problems from vibration.

Whilst assembly houses may have optimised the processes, for sure it's far more
difficult for an individual to use.

Graham

Eeyore wrote:

Arfa Daily wrote:

To N.Cook The place that I got my research material from was Tin Technology
Ltd with a website of www.lead-free.org The person that I spoke to at that
body, pointed me to www.dti.gov.uk/sustainability/weee/index.htm I also
spoke to a Dr Goodman at ERAT Technology Ltd

That's Paul Goodman at ERA Technology. The final report is here.
http://ec.europa.eu/environment/wast...nal_report.pdf

There was a simpler 30 or so page interim report I've mislaid which definitely
showed indications of problems from vibration.

Whilst assembly houses may have optimised the processes, for sure it's far more
difficult for an individual to use.

I've emailed Dr Goodman again to see if the simpler report still exists. In the
meantimes this google search gave a host of results.

" ERA interim report lead-free " without the quote marks as I tried it.

Graham

Ron wrote:

N_Cook wrote:
Ron wrote in message

It probly started off as a hairline crack around one of the soldered
joins, caused by repeated connecting and disconnecting. It started
'fizzling', no one noticed (or cared) until the amp failed to work by
which time there was a socking great hole in the board and a nasty
smell. It`a amazing how long a lot of musicians will put up with faulty
gear, prefering to ignore problems till the item stops working.

Doesn't really need a post mortem.


I agree that is the normal etiology and pathology, carrying on the
medico-speak. But this was a socking great burnt patch and billowing smoke
out of the 1/4 inch socket holes, that developed after sound check and
before use proper. Agreed there could have been long term, unnoticed, minor
fizzing but I've never seen this sort of damage in this sort of mains power
line circumstance.

I`m surprised, it`s a pretty common failure mode.
Bear in mind that the point of arcing usually comes before the
equipments internal mains fuse, but after the fuse in the plug top,
which is more often than not rated at 13amps.
Once the board starts to carbonise quite a large current can flow, and
the current is only flowing between two points it was intented to flow
anyway - at least initially. It doesnt take long for it to burn a hole
in a board.

I'd agree with your analysis. I have seen both hairline cracks such as you
mention and 'cold joints' caused by failure to use an appropriate soldering
temperature, or soldering time when soldering components with large thermal mass
such an IEC connector PCB pin ( pressure will keep it working for a while but
it'll finally go high resistance ). Even seen that on TO-220 devices.

Graham

Eeyore wrote:

Ron wrote:
N_Cook wrote:
Ron wrote in message

It probly started off as a hairline crack around one of the soldered
joins, caused by repeated connecting and disconnecting. It started
'fizzling', no one noticed (or cared) until the amp failed to work by
which time there was a socking great hole in the board and a nasty
smell. It`a amazing how long a lot of musicians will put up with faulty
gear, prefering to ignore problems till the item stops working.

Doesn't really need a post mortem.


I agree that is the normal etiology and pathology, carrying on the
medico-speak. But this was a socking great burnt patch and billowing smoke
out of the 1/4 inch socket holes, that developed after sound check and
before use proper. Agreed there could have been long term, unnoticed, minor
fizzing but I've never seen this sort of damage in this sort of mains power
line circumstance.

I`m surprised, it`s a pretty common failure mode.
Bear in mind that the point of arcing usually comes before the
equipments internal mains fuse, but after the fuse in the plug top,
which is more often than not rated at 13amps.
Once the board starts to carbonise quite a large current can flow, and
the current is only flowing between two points it was intented to flow
anyway - at least initially. It doesnt take long for it to burn a hole
in a board.

I'd agree with your analysis. I have seen both hairline cracks such as you
mention and 'cold joints' caused by failure to use an appropriate soldering
temperature, or soldering time when soldering components with large thermal mass
such an IEC connector PCB pin ( pressure will keep it working for a while but
it'll finally go high resistance ). Even seen that on TO-220 devices.

p.s. ( The TO-220 device acting as a heatsink to the solder via its leads, hence
preventing the alloying connection needed ). I've literally seen TO-220 devices
'fall out' of a PCB after a year or two leaving 3 nice rectangular holes in what
look to be perfect solder joints.

p.p.s The hairline crack around soldered joints is especially common where the
drilled hole size is not ideal ( oversize ) for the lead diameter. I have seen
manufacturers specify hole sizes very poorly with the inevitable outcome. Hence my
PCB footprints often use my own estimation of the appropriate drill size rather than
the data book one. Plenty of other people do the same.

Graham

"Meat Plow" wrote in message
...
On Fri, 22 May 2009 01:49:59 +0100, "Arfa Daily"
wrote:


"Eeyore" wrote in message
...


whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.

Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug

Yep, ring crack around a power solder connection, generates lots of
heat.

Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used in
solder in
the first place ? For fun ?

Graham


Just what I've been saying since they first mandated the hateful stuff ...

Arfa


Glad I stockpiled enough 60/40 to last me a lifetime. I could probably
sell it on Ebay for an exuberant price one day :-)

This Tin Pest stuff sounds like a serious problem though.

60/40 is still readily available here in pretty much all of the varieties
that it always was - I got a new roll just a couple of weeks ago. What was
interesting though, is that they have jacked up the price to match - almost
exactly - the cost of the dreaded lead-free, which up until recently, was
like 50% more expensive.

Arfa

Arfa Daily wrote in message
...

"Meat Plow" wrote in message
...
On Fri, 22 May 2009 01:49:59 +0100, "Arfa Daily"
wrote:


"Eeyore" wrote in message
...


whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.

Burning right thru the pcb for 1/2 inch around the L pin of the
IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug

Yep, ring crack around a power solder connection, generates lots of
heat.

Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not
enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used
in
solder in
the first place ? For fun ?

Graham


Just what I've been saying since they first mandated the hateful stuff
....

Arfa


Glad I stockpiled enough 60/40 to last me a lifetime. I could probably
sell it on Ebay for an exuberant price one day :-)

This Tin Pest stuff sounds like a serious problem though.

60/40 is still readily available here in pretty much all of the varieties
that it always was - I got a new roll just a couple of weeks ago. What was
interesting though, is that they have jacked up the price to match -
almost
exactly - the cost of the dreaded lead-free, which up until recently, was
like 50% more expensive.

Arfa



Do you know the most authorative source/group, academic or industry
expert/s, on tin-pest, lead-free solder, in-service degradation of solder in
connjunction with temperature and vibration. ie those issues, as distinct
from tin whiskers aspect that seems to have more coverage.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N_Cook" wrote in message
...
Arfa Daily wrote in message
...

"Meat Plow" wrote in message
...
On Fri, 22 May 2009 01:49:59 +0100, "Arfa Daily"
wrote:


"Eeyore" wrote in message
...


whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.

Burning right thru the pcb for 1/2 inch around the L pin of the
IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug

Yep, ring crack around a power solder connection, generates lots of
heat.

Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not
enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used
in
solder in
the first place ? For fun ?

Graham


Just what I've been saying since they first mandated the hateful stuff
...

Arfa


Glad I stockpiled enough 60/40 to last me a lifetime. I could probably
sell it on Ebay for an exuberant price one day :-)

This Tin Pest stuff sounds like a serious problem though.

60/40 is still readily available here in pretty much all of the varieties
that it always was - I got a new roll just a couple of weeks ago. What
was
interesting though, is that they have jacked up the price to match -
almost
exactly - the cost of the dreaded lead-free, which up until recently, was
like 50% more expensive.

Arfa



Do you know the most authorative source/group, academic or industry
expert/s, on tin-pest, lead-free solder, in-service degradation of solder
in
connjunction with temperature and vibration. ie those issues, as distinct
from tin whiskers aspect that seems to have more coverage.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



I spoke by email with a couple of industry advice bodies, when I was
preparing an article on lead-free solder for a mag. I'll see if I can find
the references for them.

Arfa

Arfa Daily wrote in message
...

"N_Cook" wrote in message
...
Arfa Daily wrote in message
...

"Meat Plow" wrote in message
...
On Fri, 22 May 2009 01:49:59 +0100, "Arfa Daily"
wrote:


"Eeyore" wrote in message
...








I spoke by email with a couple of industry advice bodies, when I was
preparing an article on lead-free solder for a mag. I'll see if I can find
the references for them.

Arfa



I did not find , on this site, the expected date for the results of their
study

CALCE Long-Term Pb-Free Study
http://www.calce.umd.edu/lead-free/longterm.htm

Generally, it seems to be just anecdotal evidence so far


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"Meat Plow" wrote in message
...
On Sat, 23 May 2009 02:01:09 +0100, "Arfa Daily"
wrote:


"Meat Plow" wrote in message
...
On Fri, 22 May 2009 01:49:59 +0100, "Arfa Daily"
wrote:


"Eeyore" wrote in message
...


whit3rd wrote:

On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.

Burning right thru the pcb for 1/2 inch around the L pin of the
IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug

Yep, ring crack around a power solder connection, generates lots of
heat.

Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest

Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not
enough.

The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used
in
solder in
the first place ? For fun ?

Graham


Just what I've been saying since they first mandated the hateful stuff
...

Arfa


Glad I stockpiled enough 60/40 to last me a lifetime. I could probably
sell it on Ebay for an exuberant price one day :-)

This Tin Pest stuff sounds like a serious problem though.

60/40 is still readily available here in pretty much all of the varieties
that it always was - I got a new roll just a couple of weeks ago. What was
interesting though, is that they have jacked up the price to match -
almost
exactly - the cost of the dreaded lead-free, which up until recently, was
like 50% more expensive.

Arfa


Last I bought was for copper plumbing. I tried the lead free crap and
it was laughable on 1/2 inch water pipe. I have many years experience
soldering and brazing but won't touch the lead free crap again.

I have an acquaintance who is a plumber, and some long time ago when the
stuff was first becoming mandated for electronic construction work, which
was actually some time after it became so for live water systems, I asked
him how he got on with it. He told me that at first they had a lot of
problems getting it to 'stick' to a joint, and problems with leaks. He said
that they had eventually got used to it, and that they could now make joints
as good as with leaded solder. However, he said that it required rather
different techniques to those conventionally used for plumbing soldering in
that the surfaces to be joined must be *very* clean as opposed to just
fundamentally clean, and that an aggressive flux helped. He also said that
it was funny stuff to work with in that it reached its melting point very
suddenly, and then had a tendency to run out of the joint, before re-setting
very suddenly also, so no 'pasty' phase, which I guess would knock on the
head the old technique of 'wiping' a joint. Given that copper expands very
readily, it will be interesting to see if joints start breaking and leaking
in 15 years' time due to the total lack of ductility that lead-free has.
We've all seen the effects of rather more intense thermal cycling on the
short-term integrity of electronic joints. Perhaps plumbing joints are a
ticking timebomb ... :-)


To N.Cook The place that I got my research material from was Tin Technology
Ltd with a website of www.lead-free.org The person that I spoke to at that
body, pointed me to www.dti.gov.uk/sustainability/weee/index.htm I also
spoke to a Dr Goodman at ERAT Technology Ltd

All of this was 3 years ago now, and I have not visited those sites since,
if they still exist, but they did contain some good stuff at the time, and
they might lead you where you want to go, now.

Arfa

Arfa

Eeyore wrote:


p.p.s The hairline crack around soldered joints is especially common where the
drilled hole size is not ideal ( oversize ) for the lead diameter. I have seen
manufacturers specify hole sizes very poorly with the inevitable outcome. Hence my
PCB footprints often use my own estimation of the appropriate drill size rather than
the data book one. Plenty of other people do the same.

Graham



My Dad - who taught me to solder some 50 years ago - use to say that a
good solder joint started off as a good mechanical joint.

As a teeenager, I probably spent thousands of hours wiring up
uniselectors and GPO relays with tinned copper wire and sleeving, on
every joint, the wire was either wound around the tag or passed through
a hole, if it was a lead through a circuit board, the wire was bent over
at right angles on the solder side.

We manufacturerd slot machines btw.

Ron

Ron wrote in message
...
Eeyore wrote:


p.p.s The hairline crack around soldered joints is especially common
where the
drilled hole size is not ideal ( oversize ) for the lead diameter. I
have seen
manufacturers specify hole sizes very poorly with the inevitable
outcome. Hence my
PCB footprints often use my own estimation of the appropriate drill size
rather than
the data book one. Plenty of other people do the same.

Graham



My Dad - who taught me to solder some 50 years ago - use to say that a
good solder joint started off as a good mechanical joint.

As a teeenager, I probably spent thousands of hours wiring up
uniselectors and GPO relays with tinned copper wire and sleeving, on
every joint, the wire was either wound around the tag or passed through
a hole, if it was a lead through a circuit board, the wire was bent over
at right angles on the solder side.

We manufacturerd slot machines btw.

Ron


Very true , unfortunately assembly time/cost preclude that.
Hence the notorious guitar input socket problem. The sockets used to be
wired between the chassis mounted socket and pcb , so mechanically decoupled
from routine use of the socket. Now all soldered to the board and the
insertion/removal forces are transmitted to the pcb solder joint.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N_Cook wrote:
Ron wrote in message
...
Eeyore wrote:

p.p.s The hairline crack around soldered joints is especially common
where the
drilled hole size is not ideal ( oversize ) for the lead diameter. I
have seen
manufacturers specify hole sizes very poorly with the inevitable
outcome. Hence my
PCB footprints often use my own estimation of the appropriate drill size
rather than
the data book one. Plenty of other people do the same.

Graham


My Dad - who taught me to solder some 50 years ago - use to say that a
good solder joint started off as a good mechanical joint.

As a teeenager, I probably spent thousands of hours wiring up
uniselectors and GPO relays with tinned copper wire and sleeving, on
every joint, the wire was either wound around the tag or passed through
a hole, if it was a lead through a circuit board, the wire was bent over
at right angles on the solder side.

We manufacturerd slot machines btw.

Ron


Very true , unfortunately assembly time/cost preclude that.
Hence the notorious guitar input socket problem. The sockets used to be
wired between the chassis mounted socket and pcb , so mechanically decoupled
from routine use of the socket. Now all soldered to the board and the
insertion/removal forces are transmitted to the pcb solder joint.

Even then if you bother to bend the tags over when replacing them, the
problem is less likely to recur.

Ron

"Ron" wrote in message
...
Eeyore wrote:


p.p.s The hairline crack around soldered joints is especially common
where the
drilled hole size is not ideal ( oversize ) for the lead diameter. I have
seen
manufacturers specify hole sizes very poorly with the inevitable outcome.
Hence my
PCB footprints often use my own estimation of the appropriate drill size
rather than
the data book one. Plenty of other people do the same.

Graham


My Dad - who taught me to solder some 50 years ago - use to say that a
good solder joint started off as a good mechanical joint.

As a teeenager, I probably spent thousands of hours wiring up uniselectors
and GPO relays with tinned copper wire and sleeving, on every joint, the
wire was either wound around the tag or passed through a hole, if it was a
lead through a circuit board, the wire was bent over at right angles on
the solder side.

We manufacturerd slot machines btw.

Ron

Arrrggghhh !! Dontcha just hate trying to unsolder and remove components
with bent-over legs ... ? Very true though that you should have a good
mechanical joint first. It's the way I was taught too, not quite so long
ago, but close. At college, we had to make connections to lengths of
tagstrip, without melting the insulation on the single-strand wire, as
practice pieces.

Arfa

On Sun, 24 May 2009 16:54:32 +0100, "Arfa Daily"
wrote:

Arrrggghhh !! Dontcha just hate trying to unsolder and remove components
with bent-over legs ... ? Very true though that you should have a good
mechanical joint first.

The first transistor radio (and television) pcbs were designed so that, wherever
possible, a component wire hole was /not/ in a piece of copper. This meant that
all leads had to be bent over at right angles to meet the correct piece of
copper. The great advantage of this was the ease of temporaily disconnecting a
component for test/repair. Of course this was before auto-insertion made all the
girls redundant...
(quips here)

--
Geo

Ron wrote:

Eeyore wrote:

p.p.s The hairline crack around soldered joints is especially common where the
drilled hole size is not ideal ( oversize ) for the lead diameter. I have seen
manufacturers specify hole sizes very poorly with the inevitable outcome. Hence my
PCB footprints often use my own estimation of the appropriate drill size rather than
the data book one. Plenty of other people do the same.

My Dad - who taught me to solder some 50 years ago - use to say that a
good solder joint started off as a good mechanical joint.

As a teeenager, I probably spent thousands of hours wiring up
uniselectors and GPO relays with tinned copper wire and sleeving, on
every joint, the wire was either wound around the tag or passed through
a hole, if it was a lead through a circuit board, the wire was bent over
at right angles on the solder side.

We manufacturerd slot machines btw.

Doubtless needed it to cope with the environment.

Graham

Ron wrote:

N_Cook wrote:

Very true , unfortunately assembly time/cost preclude that.
Hence the notorious guitar input socket problem. The sockets used to be
wired between the chassis mounted socket and pcb , so mechanically decoupled
from routine use of the socket. Now all soldered to the board and the
insertion/removal forces are transmitted to the pcb solder joint.

Even then if you bother to bend the tags over when replacing them, the
problem is less likely to recur.

Good point. I gather that Cadac 'hand wire' even pots to the PCB via short lengths
of wire btw.

Graham

Arfa Daily wrote:

"Adrian Tuddenham" wrote in message
alid.invalid...
Eeyore wrote:


The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used in
solder
in the first place ? For fun ?

In the past I have many times agreed with your facts, but I have often
disagreed with your way of expressing them. On this occasion I am with
you all the way.

Let's hope the first aeroplane to crash because of lead-free solder has
only Brussels diplomats and anti-lead campaigners on board.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

As far as I know, at this point in time, the avionics industry still has an
exemption from having to use the stuff. Now I wonder why that could be ... ?

They may be exempt, but what might they do when they can't get the
proper stuff any more because no manufacturer can afford to run two
production lines for the same product simultaneously and daren't risk
getting them muddled?

1) Set up special production lines.
2) Stop making avionics.
3) Change the rules and use lead-free.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

"Adrian Tuddenham" wrote in message
valid.invalid...
Arfa Daily wrote:

"Adrian Tuddenham" wrote in message
alid.invalid...
Eeyore wrote:


The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used
in
solder
in the first place ? For fun ?

In the past I have many times agreed with your facts, but I have often
disagreed with your way of expressing them. On this occasion I am with
you all the way.

Let's hope the first aeroplane to crash because of lead-free solder has
only Brussels diplomats and anti-lead campaigners on board.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

As far as I know, at this point in time, the avionics industry still has
an
exemption from having to use the stuff. Now I wonder why that could be
... ?

They may be exempt, but what might they do when they can't get the
proper stuff any more because no manufacturer can afford to run two
production lines for the same product simultaneously and daren't risk
getting them muddled?

1) Set up special production lines.
2) Stop making avionics.
3) Change the rules and use lead-free.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

There are no plans at the moment, from what I can gather, for manufacturers
to stop producing leaded solder, nor for distributors to drop it. There is
much 'legacy' equipment out there, which is manufactured in leaded solder,
and should not, as a consequence, be repaired using lead-free solder,
according to published wisdom from those who should know. There is no legal
requirement to use lead-free for the purposes of effecting such repairs. As
well as avionics, there are a number of other exemptions in important fields
such as medical equipment, and some military areas. Again, I wonder why that
could be ... ? As far as I understand it, the American military will not
tolerate the stuff being used in any of their equipment. How eminently
sensible of them. Pity we haven't got the same courage of our convictions to
stand up to the green mist brigade on this side of the pond ...

Arfa