Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only, of
the valve bases , bad solder joints, reacted to the re-soldering process as
though the tags were made of stainless steel or had a grease/oil film over
them. What could have been the cause?

In article , "N_Cook"
wrote:

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only, of
the valve bases , bad solder joints, reacted to the re-soldering process as
though the tags were made of stainless steel or had a grease/oil film over
them. What could have been the cause?

The causes of corrosion are many. I know you enjoy failure analysis as
an independent intellectual pursuit, but it isn't going to help you in
the repair. Salt air, cigarette smoke, corrosive flux used by an amateur
in a previous repair, they all have the same remedy: Remove and Replace
affected components.

Well if it's under the solder of course it was during manufacture, but
it could be earlier in the process as well. Right now I assume when
you say tags you mean pads, the copper surface on the board right ?

It may have well been the photo resist. I worked for a PCB
manufacturer for a short time when I was younger and I know
cleanliness is esential. Somebody screwed up, and now I would wonder
if the problem is not just a one time occurance. If it is on the same
part of the board in more than one unit, the process was faulty. It's
more likely though that it was just a one time thing, or maybe just a
few. When they run these things through a bath maybe the fluid got low
or something like that.

In this case I guess the photoresist was conductive enough to let the
unit work, and the thermal mass of the solder during the wave
soldering was enough to make some kind of bond. It obviously didn't
last forever but a soldering iron simply cannot do what a pool of
molten solder can.

I would be VERY interested to know if the same problem is found again
on different specimens of the same model.

J

Smitty Two wrote in message
news
In article , "N_Cook"
wrote:

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only,
of
the valve bases , bad solder joints, reacted to the re-soldering
process as
though the tags were made of stainless steel or had a grease/oil film
over
them. What could have been the cause?

The causes of corrosion are many. I know you enjoy failure analysis as
an independent intellectual pursuit, but it isn't going to help you in
the repair. Salt air, cigarette smoke, corrosive flux used by an amateur
in a previous repair, they all have the same remedy: Remove and Replace
affected components.


I did notice an amount of black copper sulphide? corrossion over the brass
of the stand-off power switches - more like usual 30 years of black from air
bourne sulphurous gases.
This was failure to solder onto the pins themselves, the pcb pad solder
adherence seemed ok.
I still tend to a production problem as just one valve base Belkin and, not
at component making, as the jack sockets are Ream UK. Maybe contamination by
flood or fire or something like that at pre-production parts storage . If it
was greasy hands of a procuction operative I would not expect both surfaces
of each tag and all tags to be affected

In article , "N_Cook"
wrote:

Smitty Two wrote in message
news
In article , "N_Cook"
wrote:

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only,
of
the valve bases , bad solder joints, reacted to the re-soldering
process as
though the tags were made of stainless steel or had a grease/oil film
over
them. What could have been the cause?

The causes of corrosion are many. I know you enjoy failure analysis as
an independent intellectual pursuit, but it isn't going to help you in
the repair. Salt air, cigarette smoke, corrosive flux used by an amateur
in a previous repair, they all have the same remedy: Remove and Replace
affected components.


I did notice an amount of black copper sulphide? corrossion over the brass
of the stand-off power switches - more like usual 30 years of black from air
bourne sulphurous gases.
This was failure to solder onto the pins themselves, the pcb pad solder
adherence seemed ok.
I still tend to a production problem as just one valve base Belkin and, not
at component making, as the jack sockets are Ream UK. Maybe contamination by
flood or fire or something like that at pre-production parts storage . If it
was greasy hands of a procuction operative I would not expect both surfaces
of each tag and all tags to be affected

I suppose one question is whether the bad soldering was original or
whether it developed over time. If original it could have been due to
corroded or poorly plated new parts as you suspect. Even well-made parts
corrode in storage (no flood required) so the mfr. may have used old
stock.

OTOH it's at least equally likely that poor original soldering was due
to operator incompetence such as insufficient heat or insufficient flux.

But of course (moving to option two) mechanical sockets are subject to
torture, and solder connections that start life healthy do crack over
time. Once cracked, the corrosion has a path to gain a foothold.

Smitty Two wrote in message
news
In article , "N_Cook"
wrote:

Smitty Two wrote in message
news
In article , "N_Cook"
wrote:

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one ,
only,
of
the valve bases , bad solder joints, reacted to the re-soldering
process as
though the tags were made of stainless steel or had a grease/oil
film
over
them. What could have been the cause?

The causes of corrosion are many. I know you enjoy failure analysis as
an independent intellectual pursuit, but it isn't going to help you in
the repair. Salt air, cigarette smoke, corrosive flux used by an
amateur
in a previous repair, they all have the same remedy: Remove and
Replace
affected components.


I did notice an amount of black copper sulphide? corrossion over the
brass
of the stand-off power switches - more like usual 30 years of black from
air
bourne sulphurous gases.
This was failure to solder onto the pins themselves, the pcb pad solder
adherence seemed ok.
I still tend to a production problem as just one valve base Belkin and,
not
at component making, as the jack sockets are Ream UK. Maybe
contamination by
flood or fire or something like that at pre-production parts storage .
If it
was greasy hands of a procuction operative I would not expect both
surfaces
of each tag and all tags to be affected

I suppose one question is whether the bad soldering was original or
whether it developed over time. If original it could have been due to
corroded or poorly plated new parts as you suspect. Even well-made parts
corrode in storage (no flood required) so the mfr. may have used old
stock.

OTOH it's at least equally likely that poor original soldering was due
to operator incompetence such as insufficient heat or insufficient flux.

But of course (moving to option two) mechanical sockets are subject to
torture, and solder connections that start life healthy do crack over
time. Once cracked, the corrosion has a path to gain a foothold.


I'll see if the owner uses it near an oil burner or something that may
locally contaminate. The mystery is why just one of the 5 valve sockets
affected. Until the surface of each tag was abraided back, the solder would
not take, just as though they were made of stainless steel. All the other
solder joins look perfect , not the slightest trace of greyness or surface
crazing . The owner's cat found the front grill ideal as a scratchpad for
itchy claws, perhaps extgremely well aimed cat urine, but again no
suspicious staining
inside

It had been kept in a shed for a couple of years

On Jan 8, 1:07*am, "N_Cook" wrote:
Smitty Two wrote in message

news


In article , "N_Cook"
wrote:

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only,
of
the valve bases , *bad solder joints, reacted to the re-soldering
process as
though the tags were made of stainless steel or had a grease/oil film
over
them. What could have been the cause?

The causes of corrosion are many. I know you enjoy failure analysis as
an independent intellectual pursuit, but it isn't going to help you in
the repair. Salt air, cigarette smoke, corrosive flux used by an amateur
in a previous repair, they all have the same remedy: Remove and Replace
affected components.

I did notice an amount of *black copper sulphide? corrossion over the brass
of the stand-off power switches - more like usual 30 years of black from air
bourne sulphurous gases.
This was failure to solder onto the pins themselves, the pcb pad solder
adherence seemed ok.
I still tend to a production problem as just one valve base Belkin and, not
at component making, as the jack sockets are Ream UK. Maybe contamination by
flood or fire or something like that at pre-production parts storage . If it
was greasy hands of a procuction operative I would not expect both surfaces
of each tag and all tags to be affected

Do you mean Belton sockets? I don't believe Belkin makes anything for
vacuum tubes.

If so, and if these data sheets are representative, the lugs are
either tin plated or solder plated:

http://www.tubes.it/belton_sockets.pdf

I found the korean website for Belton, but their tube socket data
sheet would not display for me.

spamtrap1888 wrote in message
...
On Jan 8, 1:07 am, "N_Cook" wrote:
Smitty Two wrote in message

news


In article , "N_Cook"
wrote:

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only,
of
the valve bases , bad solder joints, reacted to the re-soldering
process as
though the tags were made of stainless steel or had a grease/oil film
over
them. What could have been the cause?

The causes of corrosion are many. I know you enjoy failure analysis as
an independent intellectual pursuit, but it isn't going to help you in
the repair. Salt air, cigarette smoke, corrosive flux used by an amateur
in a previous repair, they all have the same remedy: Remove and Replace
affected components.

I did notice an amount of black copper sulphide? corrossion over the brass
of the stand-off power switches - more like usual 30 years of black from
air
bourne sulphurous gases.
This was failure to solder onto the pins themselves, the pcb pad solder
adherence seemed ok.
I still tend to a production problem as just one valve base Belkin and,
not
at component making, as the jack sockets are Ream UK. Maybe contamination
by
flood or fire or something like that at pre-production parts storage . If
it
was greasy hands of a procuction operative I would not expect both
surfaces
of each tag and all tags to be affected

Do you mean Belton sockets? I don't believe Belkin makes anything for
vacuum tubes.

If so, and if these data sheets are representative, the lugs are
either tin plated or solder plated:

http://www.tubes.it/belton_sockets.pdf

I found the korean website for Belton, but their tube socket data
sheet would not display for me.

+++++

mindslip on my part, I'd been playing around with wifi kit

"Nutcase Kook"

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only, of
the valve bases , bad solder joints, reacted to the re-soldering process
as
though the tags were made of stainless steel or had a grease/oil film over
them. What could have been the cause?


** Bad plating on the parts.

Jack sockets and valve base pins are generally nickel plated, which is very
shiny, corrosion resistant and solders easily.
However, if the plating solution is contaminated by zinc or other metals -
then the result is dull and not corrosion resistant for long.

Peavey may have been supplied such parts ( eg from China ) and installed
them on the PCBs when right on the edge of being usable - and now they are
unusable.

Anecdote:

I bought some Neutrik Speakon PCB mount sockets from the Australian agent
last year. What I got may have been old stock and the solder tags were all
but impossible to solder. Had to scrape every one with a blade and apply
humongous amounts of heat and extra solder to get a result.


..... Phil

On Sat, 7 Jan 2012 15:59:06 -0000, "N_Cook" wrote:

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only, of
the valve bases , bad solder joints, reacted to the re-soldering process as
though the tags were made of stainless steel or had a grease/oil film over
them. What could have been the cause?

My guess(tm) is that the lugs were cadmium plated. Cadmium can be
soldered with silver solder, but barely with regular 63/37. If you
must solder to cadmium plating, use a rather highly activated rosin
flux (i.e. acid), and wash off the flux before it rots your wiring and
components.

Got a UV torch? Shine it on the wiring and see if anything glows. It
will detect fungicide, conformal coatings, mouse urine, some
chemicals, and counterfiet money.
http://www.ebay.com/itm/220816271209

Incidentally, the next time you have such a question, kindly supply
some kind of physical description or photo. The color of the lugs and
tabs might be useful for determining the composition.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann"

Peavey Prowler amp from 1999. All the 1/4 inch sockets and one , only, of
the valve bases , bad solder joints, reacted to the re-soldering process
as
though the tags were made of stainless steel or had a grease/oil film over
them. What could have been the cause?

My guess(tm) is that the lugs were cadmium plated.


** Whaaaatttt ??


Cadmium can be
soldered with silver solder, but barely with regular 63/37.


** How are high volume manufacturers like Peavey supposed to use you
imaginary parts in automated soldering systems ?

Wot ********.


.... Phil

On Mon, 9 Jan 2012 10:02:35 +1100, "Phil Allison"
wrote:

** How are high volume manufacturers like Peavey supposed to use you
imaginary parts in automated soldering systems ?

Good point. I thought that they soldered the large components to the
PCB by hand.

I'll admit that I'm speculating on this, but I can't seem to think of
a better explanation (mostly due to a lack of a proper description and
photos).


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann"
"Phil Allison"

** How are high volume manufacturers like Peavey supposed to use
your imaginary parts in automated soldering systems ?

Good point. I thought that they soldered the large components to the
PCB by hand.

** But you said and SNIPPED this :

" My guess(tm) is that the lugs were cadmium plated. Cadmium can be
soldered with silver solder, but barely with regular 63/37. "

What maker would use a " barely solderable " plating on valve base pins or
jack sockets ?


I'll admit that I'm speculating on this, but I can't seem to think of
a better explanation

** So you thought of an utterly absurd one instead ?

BTW:

I see Peavey amps all the time and bad solder joints are common in examples
over 10 years old - but most of them are due to heat cycling and mechanical
stress.


.... Phil

On Mon, 9 Jan 2012 13:08:55 +1100, "Phil Allison"
wrote:


"Jeff Liebermann"
"Phil Allison"

** How are high volume manufacturers like Peavey supposed to use
your imaginary parts in automated soldering systems ?

Good point. I thought that they soldered the large components to the
PCB by hand.

** But you said and SNIPPED this :

I didn't want to confuse you with too much information.

" My guess(tm) is that the lugs were cadmium plated. Cadmium can be
soldered with silver solder, but barely with regular 63/37. "

What maker would use a " barely solderable " plating on valve base pins or
jack sockets ?

Good question. I usually don't ask why until after I've determined
that it's a real problem. It could be a bad lot of parts. However,
reading between the lines of the highly abbreviated original
description, there are two components involved, the jacks and the
valve sockets. It's unlikely that Peavey bought two different barely
solderable components. So, my guess is probably wrong. (See... I'm
easy).

I'll admit that I'm speculating on this, but I can't seem to think of
a better explanation

** So you thought of an utterly absurd one instead ?

It seemed like a possible culprit at the time. If I were to limit my
replies to only those things which were verifiable, 100.0% accurate,
and not subject to debate, then I would never post anything.

BTW:

I see Peavey amps all the time and bad solder joints are common in examples
over 10 years old - but most of them are due to heat cycling and mechanical
stress.

Thermal cycling and mechanical damage will create a bad connection,
but will not affect the solderability of the lugs.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558