Creative Gigaworks S750

[SeattleMatt]

Re: Creative Gigaworks S750

Those resistors are probably bad now too (R30 and R38)

Yeah, i'll pull them and see if i can find numbers on them

[Pentium4]

Re: Creative Gigaworks S750

You can find out their ratings by the colors on them but they look pretty charred and discolored

[Agent24]

Re: Creative Gigaworks S750

IRF740 is the model number. The rest are just date\batch codes etc, which is why you won't find a match to those.

The question is, did the MOSFET cause the power problems and finally give up or do you have bad capacitors or something else that killed the MOSFET?

As for the resistors, it looks like the other MOSFETS use the same resistor values. You should able to get the info you need from the other parts.

[SeattleMatt]

Re: Creative Gigaworks S750

IRF740 is the model number. The rest are just date\batch codes etc, which is why you won't find a match to those.

The question is, did the MOSFET cause the power problems and finally give up or do you have bad capacitors or something else that killed the MOSFET?

As for the resistors, it looks like the other MOSFETS use the same resistor values. You should able to get the info you need from the other parts.

Well, i'm not sure, I know that the unit worked well after it was powered on using the hairdryer. I started by assuming that bad caps could be fooled into working if heated up, but I didn't originally consider that other components could be affected the same way.

so how do I know which MOSFET to purchase?

[Agent24]

Re: Creative Gigaworks S750

I'm not sure either. If you have or have access to an ESR meter you could find out very quickly if the capacitors were bad.

https://ec.irf.com/v6/en/US/adirect/...ductID=IRF740A is your blown MOSFET.

You would probably find many brands of that same part, it doesn't have to come from IR. Just make sure you get the TO-220 package version, as there is also a surface-mount version which would be useless here.

Might pay to buy more than one just in case...

[SeattleMatt]

Re: Creative Gigaworks S750

Well, I went ahead and ordered these, we'll see. Maybe at least I can get it back running again and I will just not turn it off....ever.
http://part.arrow.com/item/detail/vishay/irf740apbf

[markcaps]

Re: Creative Gigaworks S750

Hi, apologies for digging up an old thread.

My friend gave me a Creative S750.When I plug in the power cable and turn on the power, there's a loud popping noise. The control pod isn't working and the subwoofer doesn't have any power light.
Its somewhat same like what TS has encountered but mine doesn't seem to have any blown caps/chips.

There are white sparks coming from this area :

I dismantled the power board and took some photos of it.

http://s772.photobucket.com/user/markz39/library/S750

Is there any way to revive this good old system?

[Agent24]

Re: Creative Gigaworks S750

Could be that brown glue has turned conductive and is causing a problem

[markcaps]

Re: Creative Gigaworks S750

i'll try to scrape it off.

there is a capacitor near the blue resistor that is damn lose, is it normal?

Could be that brown glue has turned conductive and is causing a problem

[ben7]

Re: Creative Gigaworks S750

i'll try to scrape it off.

there is a capacitor near the blue resistor that is damn lose, is it normal?

You mean, the solder connections are loose? If they are, yes that could be a problem.

It looks to me like whatever is shrink wrapped in that black plastic, near the sparking area, has burnt out. My guess is it could be a power resistor. Desolder it and see what else is behind it, and see if the soot comes from the bottom of it.

[markcaps]

Re: Creative Gigaworks S750

No smoke/ nothing burnt around that area. I've tested with a multimeter that the capacitor connections are still intact. I guess there isn't any glue.

But I noticed that this cap only has 1 leg, Would there be anything amiss here?

You mean, the solder connections are loose? If they are, yes that could be a problem.

It looks to me like whatever is shrink wrapped in that black plastic, near the sparking area, has burnt out. My guess is it could be a power resistor. Desolder it and see what else is behind it, and see if the soot comes from the bottom of it.

[Th3_uN1Qu3]

Re: Creative Gigaworks S750

I noticed that this cap only has 1 leg, Would there be anything amiss here?

It means the other has burnt off. Replace it.

[markcaps]

Re: Creative Gigaworks S750

I'll check and replace the parts.

Thanks everyone for helping.

It means the other has burnt off. Replace it.

[xavdeman]

Re: Creative Gigaworks S750

I'll check and replace the parts.

Thanks everyone for helping.

Hey BadCaps.net Forum. I'm suffering from the same sort of problem with the Creative Gigaworks S750. One morning when I woke up and wanted to listen to some jazz I noticed that my system wouldn't turn on. The power light on the back of the unit was blinking and the control pod didn't emit any light at all.
When I brought the subwoofer to some friends for advice on this problem, we plugged it in and flipped the power switch. We heard some popping noises and then the fuse was blown. We proceeded to carefully open up the unit and inspect the components. Now this is where Capxon apparently trolled us. Please take a look at CAM00178.jpg. We thought the third and fourth cap went bad because the top was convex. I ordered four replacement caps (470uF, 250 volts - instead of the original 200) and replacement fuses.

In preparation of their arrival I read the Recapping FAQ , which was very helpful for my first cap replacement.

Today was the big day, a friend and I opened up the unit again and replaced the Capxons with the caps photographed on the left @ CAM00181.jpg. We had to be careful since the new caps were slightly wider, but we managed to connect all four of them. Then we decided to open up the Capxons for a post-mortem (and some revenge). This is when Hello Zepp by Charlie Clouser from the SAW soundtrack started playing. Capxon. uses. plastic. covers. that. are. convex. for. their. caps. (take a look @ CAM00183.jpg).

Despite this shocking revelation we replaced the fuse, reassembled everything and turned the unit on. We did fix something because there was no more popping noise and the fuse is still intact. Also: the led power light on the back was blinking quicker. But it still won't turn on.
Since I am at a loss I have attached some more photographic evidence for you to take a look at.

Would removing all of the brown glue and replacing it with super glue work (I'm guessing that depends on the difference between intentionally and unintentionally conductive glue: http://www.siber-sonic.com/audio/carnage.html? Which of the two would be used here?) ? (my super glue is only rated for 50 degrees C, btw.). I noticed, for example, that in CAM00182.jpg the brown glue is connected to the steel standoff, do you think this is by design?

Or do I need to replace something else. I would be very thankful if you were to take a look at some of the pictures and respond. I will stick with this topic until it is either fixed or the consensus is that I should just bin the unit (which would make me very sad since a replacement product is prohibitively expensive for me). I can take pictures of other areas if you so require.

Thanks in advance and kind regards,
Xavier.

[xavdeman]

Re: Creative Gigaworks S750

Another picture for your entertainment. The shrink wrapped capacitor (to the left of the blue one) is a bit loose to the touch.

[Agent24]

Re: Creative Gigaworks S750

The CapXon capacitors may still have failed. I do believe that the HP series are prone to short out rather than just go high ESR. I would check the ones you removed for being short or open. They may have caused the fuse to blow and maybe other damage.

If the power light blinking is NOT a fault code, I suspect the PSU is power cycling. Conductive glue causing a short may be the problem. The glue does not need to be replaced but it should probably be removed from any component leads and other circuitry.

There may also be other blown\shorted parts in the PSU or in the other circuitry causing the PSU to cycle.

I would refer to this: http://www.repairfaq.org/sam/smpsfaq.htm for advice on checking the PSU if it is indeed a power cycling issue.

[xavdeman]

Re: Creative Gigaworks S750

I would check the ones you removed for being short or open.

I got my multimeter right here. I think I understand how to check for a short (measure resistance in Ohms, if it shows some low number there is a short?), is that also how you check for them being open? Good thing I saved them

I'll follow the power supply tutorial in the coming week (it's quite a long read I believe).

Thanks for your response and I'll keep you posted.

[Agent24]

Re: Creative Gigaworks S750

Make sure you discharge the capacitor before testing or you may get a false result or damage the meter - it should start off as a low resistance and climb higher as it charges up. If it is shorted the resistance will stay low.

If it's open, the resistance will be high from the start and it will not charge at all.

The action is much more obvious with an analogue meter, but a digital can be used.

[momaka]

Re: Creative Gigaworks S750

I think this thread needs more pictures of the power supply board. The pictures in post #1 are excellent, but a picture of the underside of the power supply would also be helpful. That way we can see how things are connected and possibly try to force the power supply to turn on to see what could be bad.

[xavdeman]

Re: Creative Gigaworks S750

Make sure you discharge the capacitor before testing or you may get a false result or damage the meter - it should start off as a low resistance and climb higher as it charges up. If it is shorted the resistance will stay low.

If it's open, the resistance will be high from the start and it will not charge at all.

The action is much more obvious with an analogue meter, but a digital can be used.

a picture of the underside of the power supply would also be helpful

Agent24 and Momaka, I'll follow both of your suggestions as soon as possible, this will probably be during this week. For now I do have some more photos (in CAM00190 you can see how we managed to get the slightly bigger capacitors in there. It's not perfect but then again, neither was Creative's work), but looking at it I realize I should definitely take one of the underside (you mean the part of the pcb that is not covered in components I suppose).

When I got more I'll make a new post in this thread!