Probably the worst bit of "soldering" i've ever seen on Citronic Digi 16P
mixer amp, Made in China it says on the rear.
An intermittant fault with one channel speaker, the wires 2.7mm diameter
over the insulation, 1.5mm or so core, the 4 wires go to a rear board for
speakons and 1/4 inch outlets. Each wire is stripped neatly , leaving some
whitish thin coating over the copper core wires that probably holds the
filaments together until solder temperature melts it . Pushed through the
large holes in the solder pads and "soldered" on the blank side of the board
with little blobs of solder relying on melting of the board composite to
hold in place, and unmelted coating plainly visible on the other side. I
assume the holes are plated through or there would be no electrical
connection possible. The assembler must have passed the wires wrong way
through and soldered the wrong side.

On Apr 5, 7:41*am, "N_Cook" wrote:
Probably the worst bit of "soldering" i've ever seen on Citronic Digi 16P
mixer amp, Made in China it says on the rear.
An intermittant fault with one channel speaker, the wires 2.7mm diameter
over the insulation, 1.5mm or so core, the 4 wires go to a rear board for
speakons and 1/4 inch outlets. Each wire is stripped neatly , leaving some
whitish thin coating over the copper core wires that probably holds the
filaments together until solder temperature melts it . Pushed through the
large holes in the solder pads and "soldered" on the blank side of the board
with little blobs of solder relying on melting of the board composite to
hold in place, and unmelted coating plainly visible on the other side. I
assume the holes are plated through or there would be no electrical
connection possible. The assembler must have passed the wires wrong way
through and soldered the wrong side.

So, no solder pads on the back? I thought a plated-thru hole had to
have copper on both sides. Further, I would think that even the
simplest board would be asymmetrical. Is the phasing messed up? Left
and right channels switched?

spamtrap1888 wrote in message
...
On Apr 5, 7:41 am, "N_Cook" wrote:
Probably the worst bit of "soldering" i've ever seen on Citronic Digi 16P
mixer amp, Made in China it says on the rear.
An intermittant fault with one channel speaker, the wires 2.7mm diameter
over the insulation, 1.5mm or so core, the 4 wires go to a rear board for
speakons and 1/4 inch outlets. Each wire is stripped neatly , leaving some
whitish thin coating over the copper core wires that probably holds the
filaments together until solder temperature melts it . Pushed through the
large holes in the solder pads and "soldered" on the blank side of the
board
with little blobs of solder relying on melting of the board composite to
hold in place, and unmelted coating plainly visible on the other side. I
assume the holes are plated through or there would be no electrical
connection possible. The assembler must have passed the wires wrong way
through and soldered the wrong side.

So, no solder pads on the back? I thought a plated-thru hole had to
have copper on both sides. Further, I would think that even the
simplest board would be asymmetrical. Is the phasing messed up? Left
and right channels switched?

+++++=

Does the plate-through process need metal either side? This board has metal
on one side only , I was only assuming it must be plated through. Set up as
A and B so difficult to say but A side amp corresponds to A side outlets but
then L & R are often swapped as far as "viewing" from the front.

N_Cook wrote:

spamtrap1888 wrote in message
...
On Apr 5, 7:41 am, "N_Cook" wrote:

Probably the worst bit of "soldering" i've ever seen on Citronic Digi 16P
mixer amp, Made in China it says on the rear.
An intermittant fault with one channel speaker, the wires 2.7mm diameter
over the insulation, 1.5mm or so core, the 4 wires go to a rear board for
speakons and 1/4 inch outlets. Each wire is stripped neatly , leaving some
whitish thin coating over the copper core wires that probably holds the
filaments together until solder temperature melts it . Pushed through the
large holes in the solder pads and "soldered" on the blank side of the

board

with little blobs of solder relying on melting of the board composite to
hold in place, and unmelted coating plainly visible on the other side. I
assume the holes are plated through or there would be no electrical
connection possible. The assembler must have passed the wires wrong way
through and soldered the wrong side.


So, no solder pads on the back? I thought a plated-thru hole had to
have copper on both sides. Further, I would think that even the
simplest board would be asymmetrical. Is the phasing messed up? Left
and right channels switched?

+++++=

Does the plate-through process need metal either side? This board has metal
on one side only , I was only assuming it must be plated through. Set up as
A and B so difficult to say but A side amp corresponds to A side outlets but
then L & R are often swapped as far as "viewing" from the front.


It was most likely some little child, not in school where he/she
belongs, slaving at the assembly plant with make shift tools, trying to
earn enough to get rice for today's meal at home.

Jamie

On Friday, April 6, 2012 12:26:27 AM UTC-7, N_Cook wrote:
....
On Apr 5, 7:41 am, "N_Cook"
wrote:
Probably the worst bit of "soldering" i've ever seen on Citronic Digi 16P
mixer amp, Made in China it says on the rear.
An intermittant fault with one channel speaker, the wires 2.7mm diameter
over the insulation, 1.5mm or so core, the 4 wires go to a rear board for
speakons and 1/4 inch outlets. Each wire is stripped neatly , leaving some
whitish thin coating over the copper core wires that probably holds the
filaments together until solder temperature melts it . Pushed through the
large holes in the solder pads and "soldered" on the blank side of the
board
with little blobs of solder relying on melting of the board composite to
hold in place, and unmelted coating plainly visible on the other side. I
assume the holes are plated through or there would be no electrical
connection possible. The assembler must have passed the wires wrong way
through and soldered the wrong side.

So, no solder pads on the back? I thought a plated-thru hole had to
have copper on both sides. Further, I would think that even the
simplest board would be asymmetrical. Is the phasing messed up? Left
and right channels switched?

+++++=

Does the plate-through process need metal either side? This board has metal
on one side only , I was only assuming it must be plated through. Set up as
A and B so difficult to say but A side amp corresponds to A side outlets but
then L & R are often swapped as far as "viewing" from the front.

Plating through requires at least one side to be metallized to provide electrical contact for plating current. A board is drilled and sensitized then plated through all before the circuit process is started. It is unlikely that a true 'single sided' board would have plated through holes simply because the sensitizing and pre-plating of the holes would also plate the bare side of the board.
I would suggest that the wires were put through the 'wrong' way and the solder application had little chance of making any connection whereas if they were put through the correct direction the connection would have been fine. Sloppy supervision and QA [if there was any].

Neil S.

nesesu wrote in message
news:30[email protected]...
On Friday, April 6, 2012 12:26:27 AM UTC-7, N_Cook wrote:
...
On Apr 5, 7:41 am, "N_Cook"
wrote:
Probably the worst bit of "soldering" i've ever seen on Citronic Digi
16P
mixer amp, Made in China it says on the rear.
An intermittant fault with one channel speaker, the wires 2.7mm diameter
over the insulation, 1.5mm or so core, the 4 wires go to a rear board
for
speakons and 1/4 inch outlets. Each wire is stripped neatly , leaving
some
whitish thin coating over the copper core wires that probably holds the
filaments together until solder temperature melts it . Pushed through
the
large holes in the solder pads and "soldered" on the blank side of the
board
with little blobs of solder relying on melting of the board composite to
hold in place, and unmelted coating plainly visible on the other side. I
assume the holes are plated through or there would be no electrical
connection possible. The assembler must have passed the wires wrong way
through and soldered the wrong side.

So, no solder pads on the back? I thought a plated-thru hole had to
have copper on both sides. Further, I would think that even the
simplest board would be asymmetrical. Is the phasing messed up? Left
and right channels switched?

+++++=

Does the plate-through process need metal either side? This board has
metal
on one side only , I was only assuming it must be plated through. Set up
as
A and B so difficult to say but A side amp corresponds to A side outlets
but
then L & R are often swapped as far as "viewing" from the front.

Plating through requires at least one side to be metallized to provide
electrical contact for plating current. A board is drilled and sensitized
then plated through all before the circuit process is started. It is
unlikely that a true 'single sided' board would have plated through holes
simply because the sensitizing and pre-plating of the holes would also plate
the bare side of the board.
I would suggest that the wires were put through the 'wrong' way and the
solder application had little chance of making any connection whereas if
they were put through the correct direction the connection would have been
fine. Sloppy supervision and QA [if there was any].

Neil S.


++++

I cannot see plating as being able to carry much current compared to normal
even 1oz cu covered board. There was another problem in the ps that probably
related to plate-through and inability to carry current to a 2W resistor .
Traces on both sides of this board, soldering one trace from the blind side
as impossible to get a soldering iron in , on the correct soldering side,
and this join had "burnt"