Gigaworks S750 gone boom (in a bad way)

[Inimbrium]

Hi all.

I've got a set of speakers called Creative Gigaworks S750 and they've gone out with a bang. When they work they are a truly fantactic piece of kit and I'd love to be able to fix em. I don't like throwing expensive stuff away when it might still be fixable. It would be such a waste.

The in-built fuse went and I changed that for another only to have that go too. I've taken the sub apart because that's where the amp is and where the flases were coming from and I've found a smokey part on the PCB. Nothing else appears to be smokey or fried. I think it's a ceramic disc capacitor but I'm not sure. See what you think. This is what it says on it:
sec 471k
sb 250v~x1y1
400v~c
And it's blue with two terminals.
Here's a pic of one from another forum. It's the one encircled in red at top right:
https://www.electro-tech-online.com/attachments/02-jpg.46086/

I have three questions really:
1. If I replace it will it just blow again like the fuse did?
2. So could it be something else causing it to break?
3. Where can I get one from? I ask this because I found a few sites that sell electronic components but I'm at a loss as to what to search for. A direct link to the actual product would be fantastic.

Also I'd love to understand what it is and what the heck 'sec 471k sb 250v~x1y1 400v~c' means lol

Regards,

Rafael

 

[ben7]

I see your problem!!!

See the big brown capacitor on the right of the picture?
Its top end is bulging, indicating that it is bad.

That might not be just so however-

-A power surge could have blown something else, and made the cap bulge too

Pull some of the parts-driver MOSFET- capacitor- bridge rectifier-etc.. and use a Multi-Meter to see if any of them are shorted.

-Ben

 

[tunedwolf]

The blue capacitor that you think is blown, doestn't look blown. It's a class X2 rated capcitor. Those are rated for across the mains, and when blown are real obvious. Your problem will most certainly be start up capacitors and resistors allowing the output to climb until the fet chopper transistor failed. This will also take out the smps fet driver chip and probably the low ohms resistor on the fet. Replace all small capacitors with low esr 105 degree types in the primary of the supply and the fet and the smps driver chip. Lift one end of all the resistors in the primary and measure them, I suspect at least one of them will read high or open. On an odd occasion the opto coupler and or TL431 type regulator may also be damaged.

rgds

 

[Inimbrium]

Sorry for creating unnecessary confusion. That isn't a photo of my PCB, it's unrelated to my problem and is form another forum. It came up in google images when I seached for sec 471ksb 250v~x1y1 400v~c. I was merely using that photo as an example of what the capacitor looks like. I apologise.

I've thoroughly checked my PCB for damage and the blue capacitor is the only visible faulty component, however if you'd like a hi-res photo it can be arranged.

 

[Exo]

Those caps can short circuit on their own - probably took out the fuse (the black round thing above the caps saying 3.15A) - i'd try replacing those caps and fuse.

 

[tunedwolf]

Ok, I sort of agree with Exo in this case, they do have a tendancy to go short for no apparent reason, usually over volts, but will usually blow themselves apart or crack and split open. Replace them and the fuse, but before powering it up, measure the chopper fet and bridge rectifier for shorts.
I would still replace the low value capacitors in the primary at this point, no sense in risking the smps going into orbit if they are faulty.
A hi-res photo of the actual board will help folks get an idea of the kind of smps in use.

 

[Inimbrium]

Ok I've taken some photos of all the various boards:
This one's the overview of all the boards: www.inimbrium.0catch.com/pics/Sub/IMAG0132a.jpg

Here's a closeup of the cite where the capacitor was (I've ripped it off so that I could see the markings): **broken link removed**

Here's the top part of the main pcb: **broken link removed**

Another angle of the top part: **broken link removed**

One of the daughter boards: **broken link removed**

A different angle of the same board: **broken link removed**

Yet another board: **broken link removed**

And lastly underneath there the main caps are: **broken link removed** Is it just me or do those two bulging ones look blown?

Do you guys know any good British websites where I can buy these faulty parts?

 

[Inimbrium]

Hmm. I posted the photos yesterday but the admins haven't approoved it yet...

 

[Inimbrium]

Hi.

I'm gonna repost the photos because now that I've got 3 posts I don't have to wait for the mods anyway.

First photo shows the whole of the PCB complex: **broken link removed**

The second is a closeup of the area where the faulty cap was (I've taken it off). Also note the scorch marks. It was in the oval area marked C7: **broken link removed**

The third is of the top part of the main PCB: **broken link removed**

Thr fourth is of the top part aswell, but from a different angle: **broken link removed**

The fifth is of a daughter board on the side of the main pcb: **broken link removed**

Sixth is of the same board but at a different angle: **broken link removed**

Seventh is of yet another board (This thing has a lot of boards): **broken link removed**

And the eighth, and perhaps the most important, is of the bottom part of the main pcb where some very large caps are. Note how two of them are bulging? **broken link removed**

Does that mean they're fried? And how will that affect the other damaged blue one? And where on earth do I buy these things? And what am I looking for? lol A lot of questions I know.

 

[House0Fwax]

Post the photos here, the other site won't allow what they call 'hot linking'. Use the 'insert image' button on the top of the 'quick reply' form, or click on the 'go advanced' button.

 

[cowana]

Those big 470uF 200v capacitors are Capxon - a make well know for failing after a few years. Those caps are definitly bulding, and need replacing - it is possible they are completly the reason for failure. Definitly replace them before trying anything else.

Andrew

 

[tunedwolf]

I have the same errors about hotlinking, and therefore can't see the images that you posted. Add the images here so that we can see them using the insert image button at the top of the posting window.

rgds

 

[Inimbrium]

Ok, here's a repost with the images inserted, and reduced in size in order to save the forums bandwidth (they were half a meg each!). I can post the original 8 Megapixels at request.

First photo shows the whole of the PCB complex: **broken link removed**

The second is a closeup of the area where the faulty cap was (I've taken it off). Also note the scorch marks. It was in the oval area marked C7: **broken link removed**

The third is of the top part of the main PCB: **broken link removed**

Thr fourth is of the top part aswell, but from a different angle: **broken link removed**

The fifth is of a daughter board on the side of the main pcb: **broken link removed**

Sixth is of the same board but at a different angle: **broken link removed**

Seventh is of yet another board (This thing has a lot of boards): **broken link removed**

And the eighth, and perhaps the most important, is of the bottom part of the main pcb where some very large caps are. Note how two of them are bulging? **broken link removed**

Does that mean they're fried? And how will that affect the other damaged blue one? And where on earth do I buy these things? And what am I looking for? lol A lot of questions I know.

EDIT: Cowana, in that case should I replace the working ones too as a preventitive measure?

 

[ben7]

You definitely need to replace all of the caps in that-CapXon, JunFu, and G-luxon are crap!!!!!!!!

-Ben

 

[audioguru]

Why does Creative ruin their reputation by using garbage parts?

 

[audioguru]

I didn't know that Creative is an Oriental (Singapore) company. That explains why garbage parts are used in them.

 

[Inimbrium]

Does anyone know where I can buy these parts in the UK? Do you guys know of any good websites?
And where will I be able to find one of these:
sec 471k
sb 250v~x1y1
400v~c

I don't really know what it is. Or what to look for on a website...

 

[Inimbrium]

Bump!

Anyone? I really need to know what that small blue cap is as I'm really stuck.
This one:
sec 471k
sb 250v~x1y1
400v~c

Thanks.

 

[Nigel Goodwin]

It's 470pF 250V - why do you think it's faulty?.

 

[Inimbrium]

It's 470pF 250V - why do you think it's faulty?.

Because there are burn marks on the PCB near it. Have a look in the second photo. There's is a closeup of the area where the faulty cap was (I've taken it off). Note the scorch marks. It was in the oval area marked C7.

Thanks for the info.