Gigaworks S750 repaired by Regenboog Heerlen

[skybu...@hotmail.com]

Hello,

Finally some happy news from me regarding the Creative Labs Gigaworks S750 !!!

These guys at:

http://www.rbheerlen.nl/

Managed to repair it !

They ordered some parts, and repaired it the same day ?!

Amazing !

And I can verify it sounds fantastic !

Maybe my unit was an easy repair or maybe not, I don't know... one guy told me they ordered some kind of "supply part".

The big somewhat fat (:)) guy with the red face probably doesn't know much about electronics, but the bold guy does he claims 40 years of experience !

I believe him ! especially now too !

I think they have "personel" allowing them to do quick repairs ???

Anyway... if you have a "dead" gigaworks S750 too and you live in The Netherlands or Germany or Belgium you could give these guys a try cause it worked for me !

And best part of all it was pretty cheap only 95 euros !

Can't go wrong with that !

If they cannot fix it for some reason they would have charged me 15 euros.

But they insisted they can repair anything ! :)

I'd take them up on that offer if I was you with a dead gigaworks s750 !

I also asked the big fat red-faced guy if they will accept more units for repair and he said YES ! No problem ! Not sure if the bald guy will agree with that, but probably yeah... good for bussiness ! ;)

Sigh... for now I am skeptical... I expect the unit to die soon again... I don't know if I should trust the repair... but I will continue enjoying the fixed unit and blasting the shit out of that subwoofer and electronics ! LOVING IT !

I have 3 months of warranty on repair... I have not yet opened it up to see what they did to it... Maybe in the future I will, especially if it breaks down again.

For now may the subwoofer power be with YOUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

BOOOOOOOOOM
Bye,
Skybuck ! ;)

P.S.: I had to re-calibrate the speaker assignment via THX to swap "side left" with "subwoofer" since creative labs cables a bit different ! ;) :)


WIEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE ONE TOTALLY THRILLED SKYBUCK !

P.S.2: So glad I did not listen to my mother which always wants me to throw away stuff ! LOL... No way I am throwing away a THX certified Lucas Arts approved system ! =DDD HIHIHIHIHIHI

BYYYYYYYEEEEEEEWIEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

[skybu...@hotmail.com]

I was playing X-Com 2 The Chosen or something... there was a cool mission with protecting resistance fighters and suddenly I heard this loud POP.

I think something exploded inside the subwoofer.... or maybe the fuse blew...

Not sure yet what happened, but the Gigaworks S750 is now dead !

It was fun while it lasted.

Fortunately I have 3 months on repair... I am gonna bring it back... see if they can fix it again.

I guess this normal... fixing part by part until it hopefully doesn't die anymore :)

Sound/subwoofer was pretty cool but I think a new/replacement sub might be just as fine if not finer... I think the speakers probably worked a little bit better on the denon receiver but this could also be because of slightly different volume levels... turning the volume up via control pod seemed to give same quality.

Bye,
Skybuck.

[skybu...@hotmail.com]

As I suspected, the fuse of this device blew, probably saving my life from electric shock ? Hmmm...

The brown glue does not seem to be removed by repair company, me not to happy/thrilled about that.

I took some pictures of their repair job. They seemed to have cleaned off some brown glue from a blue thingy... or even replaced it... I wonder if more damage now occured to this device or not...

The big black capacitators are still surrounded with brown glue, this has to be cleaned off I think.

Here are recent pictures of internals of device and blown fuse:

http://www.skybuck.org/GigaWorksS750/RepairedAndDeadAgain1/

Tomorrow I will take it back to repair shop.

Bye,
Skybuck.

[Paul]

Being surrounded with brown glue isn't a problem.
Like, if the glue holds the plastic sleeves on the
capacitors together.

It's when the glue is on any high-voltage areas
of the PCB, there could be an issue.

Good luck with your repair loop.

Paul

[skybu...@hotmail.com]

First couple of pictures are a bit dark and manual focus, the rest are better.

Starting from this one:

http://www.skybuck.org/GigaWorksS750/RepairedAndDeadAgain1/IMG_9046.JPG

My best is that this glue might be deeper then it looks, I have seen others replace it. Could also be that these caps are not good enough or something or empty.

Anyway I have a new hypothesis:

Perhaps the brown glue becomes more conductive when it's hot. The device gets quite hot. I've written this on a piece of paper and hoping to pass this along to repair guy.

Thx for writing !

(Also uploaded some more pictures of rest of device in case you missed it... a few minutes later ;)... much less glue on these parts and kinda look okish)

Bye,
Skybuck.

[Paul]

Since the fuse blew, maybe they'll get lucky and figure
out what became a short circuit.

It's also possible the fuse is a new one, and replaces
the fuse that was previously in the circuit. Do you know
whether the fuse was blown on the first failure ?

Paul

[skybu...@hotmail.com]

Hi Paul,

Yes the fuse blew on the first failure, it blew while it was in use.

So first week it worked, the device gets pretty hot, suddenly it blew.

So that's why my hypothesis is based on the "hot glue" becoming conductive...

It blew all of a sudden... so why would it only blow after a certain ammount of time ?

On the other hand... my gutt feeling tells me something else must have gone bad.

I am a bit worried only the fuse will be replaced and nothing done about the actual cause.

So perhaps I will ask repair man/company about this... maybe I should do a test with a new fuse to see if system remains completely dead or if it comes back alive on first try...

What you think about this last part ?

Not sure if repair company will want to perform such a simple test ?

Even if the device would all of a sudden work again or "green up" or something... could still ask them to have a look at it... hmmm will have to discuss this what them.

Will do so very soon.

Bye,
Skybuck.

[Paul]

I would discuss the fuse with them. Maybe the original fuse
was a Slo-Blow fuse ? The fuse type must be carefully selected
for the application - the fuse must not blow with normal loading
present, and only blow when the electronics have failed. Cartridge
fuses are available in more than one type, and you select a fuse
type based on design intent.

As an example, the fuse in an ATX PSU is the Slow type. That fuse
almost never blows. It would take a short right across the AC power
rails, for the ATX fuse to blow. Lots of ATX power supplies fail,
and the fuse remains intact. The ATX fuse is "regulatory", and
is intended to show that protection is present, covering
"catastrophic failure". You use "Fast" fuses, when you want to
protect the electronics, and the fuse blows well before there
is a chance of a fire etc. By using a "Fast" fuse, there is a
risk it will blow in normal usage. (At work, we used "Pico"
fuses for lab prototypes, and did have them trip in normal usage,
even when over rating them.)

I expect in this case though, the failure is a real one, and
that glue is shorting something out.

*******

The only way those speakers are going to remain "repaired", is if
the electronics are repackaged so they run cooler.

Paul

[skybu...@hotmail.com]

I would guess/expect them to figure out which Fuse to use because there is some information about it on the box and the fuse itself and such.

I also contact repair specialist in England for his thoughts on this first repair, he wrote:

"
Whilst I cannot comment on work carried out by another company I will say
that repairs to the S750 power supply board are very difficult and that I
went through a steep learning curve when I first started to fix them.
There are plated holes under the black capacitors that get damaged by the
glue. That is why the glue has to be removed so that the board can be
inspected and repaired.There are several spots on the board where the glue
must be removed but it is not essential to complete remove all traces.
"

So what I think he is writing here is that the underside of these capacitators have a "plate" which might cause short circuit because of glue or something like that...

Hmmm will ask him further for some more clearification ;)

Bye,
Skybuck.

[Paul]

A fiberglas substrate, can have copper tracks on one side, or
on both sides.

The cheapest consumer items, have copper tracks on just one side.
This reduces the material cost of the PCB to make the item. Some of
the connections on such cheap items, are made by jumper wires.

High tech items like computer motherboards, use multilayer boards.
These are a "sandwich" of the simpler type of substrates, pressed
together in a big press. A 4-layer board would be two 2-layer
substrates, joined together. At work, we used PCBs with 12 layers
to 16 layers, and the blank PCBs can cost as much as $300 each
depending on features.

When you have plenty of layers, there is no need to run tracks between
the legs of the capacitors. You can run solid copper or cross-hatch
copper on the outer layers for copper balance or EMI containment,
and hide the actual signal tracks inside the PCB. And the thickness
of the copper, defines its current carrying capability. Thickness
is 1/2 oz, 1 oz, 2 oz, and a "power board" might use 2 oz for all
layers. The thicker the copper, the narrower the track can be,
for a given current carrying capability.

When signals pass from one layer to another, that is done with a "via".
The central cylinder of copper is the "fillet" and is plated up. First
you drill the hole through the laminated board. Then, you plate
copper into the hole, to build up the walls. The plated copper conducts
from one side of the board to the other, and joins any copper on
inner layers that touch the sides of the hole. The minimum diameter
of a signal via is limited by the "aspect ratio" of the hole, and
the thicker the PCB is, the larger the diameter of via is required
for a given aspect ratio.

https://en.wikipedia.org/wiki/Via_(electronics)

Holes for the electrolytic capacitor legs, are a larger diameter,
but use a similar construction. There can be copper rings on
top and bottom of the hole, or a copper ring just on the side
with the copper. The rules for constructing PCBs, takes
a stack of paper two feet thick, and I don't know all those
rules by heart. But I have worked with people who have memorized
practically the whole thing, just by using the specs. And I consult
with them, for the correct construction of things like that.

For high voltage circuits, there are "creepage and clearance"
requirements, and some copper constructs are not used, because
of the danger of a short underneath something, if enough dirt,
dust, or debris collects over the life of the item.

http://blog.optimumdesign.com/clearance-and-creepage-rules-for-pcb-assembly

The plated holes under the cap, would either refer to the top
of the hole the legs of the capacitor uses. Or would refer to
via conductors unrelated to the capacitors. And a designer
wouldn't necessarily want to put vias in that area.

There really shouldn't be glue under the cap. The glue selected
should be viscous enough to stay put where it is applied. There
are liquid underfills in electronics, that "flow" underneath
things on purpose, but this is not an example of where to use
them. I can see they've applied glue around the base ring
of the capacitor, and that's about as close as it gets.
Putting glue underneath the capacitor before installing it,
would be a mistake. The whole purpose of the glue, is
mechanical rigidity, and gluing the capacitor plastic sleeves
to one another, helps just as much as gluing the base
of the capacitor to the PCB, but is "safer".

A good electronics design is "re-workable". That means on
the manufacturing line, if a component is defective, staff
can remove the component and put in a good one, and still
sell the item. This reduces the pile of junked electronics
in the garbage, outside the plant. Glue should only be applied
after the board is tested and known to be good electronically.

And selecting the chemicals used for stuff like this, is
pretty difficult. If you want the item to have a long life,
you cannot use just any old glue. Good industrial glues
exist for a reason, and I suspect the glue used in the
S750 was "whatever is the cheapest", as the glue was susceptible
to heat.

Paul

[skybu...@hotmail.com]

Hi

Ok seems like together we could get to the "bottom" of this !

Here is reaction from "repair specialist":

"
The printed board is double sided and there are connections from one
side of the board through to the other. These connections are getting
corroded by the glue.
"

So this is some new information and possibly even a new hypothesis of what is happening to these boards and causing short circuits.

"Corroded" he writes. Could this be causing the short circuits ?

Hmm an interesting hypothesis.

Bye,
Skybuck.

[Paul]

You cannot really stop corrosion like that.

It all depends on how the PCB is coated, as to how protected it is.

For the bottom of the board, there is HASL (hot air solder leveling), which
coats the copper with tin/lead. Then, a conformal coating goes over top of
that, leaving gaps in the coating, so you can apply solder to points that
need to be soldered.

On the top side, there is solder mask, and there can also be conformal coating
applied.

The copper tracks themselves, can have a plating applied to the top
layer. Some assemblies can have gold (precious metal) applied
over the copper. Gold is quite resistant to chemical attack. It may
take a sequence of metals, plated up, before the gold is applied.

For the PCBs I made a home in the kitchen, those had no coating at
all, and it only takes about ten years, before chemicals in the air
eat through the copper tracks, ruining the circuit. I built my own
digital clock, with vacuum fluorescent display tubes, and that's what
happened to the PCB. In school, we coated PCBs with silver on the copper
tracks, which doesn't give too much extra protection, but is better
than nothing. That isn't electroplated, and is done just by dipping
the board in a toxic chemical brew with silver in solution.

*******

The eating of the tracks, is not causing the fuse to blow.

There is a conducting path there somewhere, which is a problem
and needs to be cleaned up. The design would have to be checked
on the primary side of the buck converter, where the AC from the
wall is rectified to DC and rests at a high voltage. The
secondary side (the voltage all the Class D amplifiers share),
that should be a lower voltage, less susceptable to "flash/bang"
accidents :-)

AFAIK, your amp is ten channels, sharing a common programmable
rail voltage, and the controller chip sets the common rail voltage
high enough for the "loudest channel". The sub has three channels
tied to it, to get three times the power, leaving seven channels for
the satellites. By making all the amplifiers the same, they need the
same rail voltage, and thus, can share the same power source. It
is that common power source, that is the most dangerous part
(as it has the high voltage on the primary side). And the glue ?
I don't know if there is a good chemical way to remove it.
Scraping it, is a mistake, because of the other damages that
could cause. If there was a good solvent for the glue, I'm sure the
repair people would be ecstatic.

Paul

[skybu...@hotmail.com]

Some evidence is found for this hypothesis, which also happens to be an amp/audio restoration/repair guy:

http://www.cdkands.com/corroded.html

Very interesting:

"Every lead in contact with the glue is corroded. The green color indicates copper oxide. I am no chemist
but I believe that the glue becomes conductive, creating an electrolyte that allows a current flow across the
board. This sets up a condition for electrolysis to occur between the copper core of the lead and the silver/lead
tinning.
"

The lead had eroded clear through and caused the failure of the channel

In this sense/context eroded means something different from corroded... I think in this sense he means "eroded" is like this stuff start crawling across the board creating unwanted connections... apperently a few millimeters is already enough to cause havoc ?

Not entirely sure why this would cause havoc... on the picture show... since that lead is going to the resistor anyway ? Hmmm...

[Shaf Ali]

Hi there, I have the same problem in the UK, my sub blew the fuse, can anyone recommend any repair service please?
thanks
Shaf

[Skybuck Flying]

There was a guy in UK, he called himself high view electronics or something, I think he stopped, not sure.

I recommend you replace the sub electronics with a denon receiver and hdmi cable for audio, set windows to dual screen output should do the trick. For older systems RCA cables for video/plugs can be used to connect to soundblaster.

I still have the sub, would be cool to bring it back alive with standard sub panel, not sure if it will fit and connect, the woofer is triple coil which is rare/strange.

I promised myself a working or new sub for new computer, though i have my doubts if it is worth the space, booms and possible ear damage -> shooters/rts/world of warships, but for wows and shooters would be cool.

I suspect better/new powered subwoofers might be out there.

It is strange to think that sub does not enhence surround sound, but it seems like it does.

Good Luck,
Skybuck.

[Paul]

In your newsreader, look in the uk.* hierarchy, for the nearest
newsgroup for your question. Those people have a much better
idea who you can trust with such a repair.

And remember that, it is not that the repair itself is
difficult, it's that awful glue that is all over the place.
That has to be cleaned up. And it's not easy to get that
stuff off. If the glue had not been used, your sub would
still be working. The glue becomes conductive when it
breaks down chemically.

Paul

[Skybuck Flying]

The repairmen I sent it to disagreed, he believed cracked pcb/traces.

This subs gets hot inside so I believe, glue might prove that a bit too, plus this sub leaked power, I could feel it in hand when touching heatsink, for these reasons I recommend replacement with high quality denon receiver , safety first , plus bonus receiver can enhance sound with modes/audio processing .

Bye,
Skybuck