Nippon KMF are actually 16mm, guess would not fit perfectly. They should be authentic, but I'm not 100% sure.

Looks like I will buy from Digikey anyway.

Thanks for the info!

With Digikey, besides Rubycon ZLH and Rubycon ZLJ, there are choices there (with 12.5mm diameter and 5mm lead pitch/spacing) such as Nichicon HE, Nippon Chemi-con KZE, Rubycon ZL and Rubycon YXG.

Hi, lex.
First af all, I am very thankful to you for this thread.
I have also a problem with my S750 set.
One day my S750 did not give the power at all. The main fuse was blown out. But I found also that on both amp.boards C40 were burned out totally - see picture.
Other components seems OK.

So because it was not clear why it happened, I decided to replace all components what were available at the Digi-Key.
Thus most of passive components were replaced - my BOM file is uploaded too. I did not test transistors/power ICs, but visually they were good.
At the final phase when I must to test my S750 I found that I lost my marks about how to connect amp. boards to the IO-board (the board with inputs/outputs) and to the power board.

Maybe somebody here can give me information about that.
 partlist.doc ( 79.5k ) Number of downloads: 773


This post has been edited by kukruse: Jan 23 2014, 04:14 PM

Have to check the 4th unit first (was sent all the way from another country) for that C40 capacitor value. If that fuse blew then there must have been quite a short somewhere. Also those burned capacitors may indicate excessive ripples and voltage surges on the power rails...

Better check the MOSFETs, due to that blown fuse. Sometimes failed MOSFETs show no signs but can be shorted internally (usually between the gate and the source, and/or between drain and source). Also check all fusible links (those zero Ohm thingies). As for that list, all looks good though that Nichicon CY is a little skinnier/smaller than the Nichicon CS I've chosen. Just make sure all have correct diameter, lead spacing and proper height (not too tall until touching the toasty heatsink, which will shorten the lifespan of the capacitors).

This post has been edited by lex: Jan 23 2014, 09:48 PM

Hi, lex,

I had someone tried to repair s750 which has small distorted sound for me but not succeed,, I can see one resis blown (R30, R39? can't remember). The guy said once he replaced the blown one, it's good, but after he turned volume up it blown again. What could be the problem? And when I got the power board back, it's missing some components, I guess the guy didn't put them back. Could you tell me the info about R30, R39, R31, D24, R23, R42? Digikey links would be perfect, appreciated.

Chris

lex, thanks for your reply.
I have checked 4x big MOSFET on power board and it seems that they are OK - at least there is resistance between all the pins.
All components what are in the list are already placed on the boards.
Right now I don't know how to connect boards to each other.
Could you give me some advice about that?

This post has been edited by kukruse: Feb 3 2014, 09:27 PM

For those components on the power board, then check Post #37...

There could be components with voltage break down (which usually would require an insulation/breakdown tester), especially those non-electrolytic capacitors and MOSFETs (leaky transistor). Can use the series light bulb method to check for shorts and/or breakdown (if insulation tester not available at the moment). As for the amplifier boards, there should be another regulator there (usually a Buck switching type) for the BASH power amplifier I.Cs thus do check them (for shorts and other failed components)...

This post has been edited by lex: Feb 5 2014, 04:13 PM

Hi lex,

I see in your second repair, the solder pads were damaged, how did you solve this? I got this problem too, they came off very easily. I am trying to repair my another s750 which has a problem have to switch on twice with controller. BTW, do you have any idea what cause this problem?

I just changed 4 big 470uf cap, one of the solder pad is damaged. Now when I switch on the speaker with controller, there is a "don" sound, it's not very lound but not small either, didn't have that before, so I turned it off right way in case cost more damage.

Edited,

I just found information from previous posts, so basically these components like caps are connected on top layer, not the back layer where leads are, right? So I need to connect the leads to the top layer to fix the damaged solder pads problem.

And can I just mount them on the back, so the leads are soldered on the top layer, maybe not the big caps but other small components?

This post has been edited by chrislue: Feb 14 2014, 08:41 PM

i am envy you guys know how to fix this electronic stuff, my speaker broken i don know what to do with it, constant noise aww

Try replacing the DIACs near the main power section (where the bigger SMPS transformer is located)...

As for fixing that solder pad through hole problem, check my previous/earlier reply here: Special Interest -> Home Entertainment -> Audiophiles ->Creative GigaWorks S750 7.1 speaker repair, A short guide and info with pictures... (PC Audio) -> Post #21. Looking at the comments, you also need to learn some basic of electronic repairs particularly understanding the circuitary (in other words able to read where and how the components are connected, as well as tracing out the paths). One side/lead/leg of the capacitor is connected to the top side layer via that through hole. For double sided boards, usually each through hole has a connection to both top and bottom sides of the circuit board (there's a tinned copper tube inside the hole).

What is the speaker brand and model?

Each lead of component like a capacitor is actually connected into circuitry on only one side of the board, am I understanding correct?


Anyway, every time when I switch on the speakers with controller, there is a pop sound, didn't have that before, is this due to capacitors failure to connect? I only changed the 4 big 470uf capacitors.

Thank you.

Not every capacitor lead/leg is connected like that. Cannot simply assume, always check the connections of component first (as you do not want create unwanted shorts and wrong connections). Again, re-quote from my earlier post here: Special Interest -> Home Entertainment -> Audiophiles ->Creative GigaWorks S750 7.1 speaker repair, A short guide and info with pictures... (PC Audio) -> Post #90... That's right, read, trace and understand the connections....

Have you removed all the degraded glue in the first place? Did you properly check the connections properly repaired on those damages through holes (requires a multimeter)? Also try replacing all the capacitors, not just those 4 big ones only....

This post has been edited by lex: Feb 15 2014, 03:12 PM

edifier s330, same problem also, constant noise, but the sound more like duuuuuuu....

http://www.youtube.com/watch?v=m2yBSXv0gc0...player_embedded

This post has been edited by watermineral: Feb 16 2014, 06:10 AM

I just checked the stock caps I pulled out, found out that almost every copper tubes inside through holes have also been pulled out with caps leads.

Looks like I have to use the "L" way to fix them all.

Is there any good way to avoid this? I tried use solder sucker, didn't work very well, so basically I just melt the solder and then pull out caps by force.

Could be either the power supply section and/or audio power amplifier section. Hard to say until examined closely the internals...

Can ignore the leads that are connected to the bottom side, just repair the leads that are connected to the top side. Check carefully the location to place the "L" wire on the top as to prevent unwanted connections.

If use that method, then pull them by tilting the capacitor side to side with one lead/leg at a time. The problem is that there is solder between the leads/legs of the capacitor and the tube surface inside that still remained. Usually can be pulled out easily but if the leads/legs are tight inside the hole then the soldering iron had to stay a little longer (to completely melt the solder inside the hole), and that usually can result in the tubes and solder pads coming off due to prolonged heating (as the soldering iron melts the glue than holds them in place). And yeah, desoldering double sided board can sometimes be very difficult as well, especially when there is solder still inside the through hole. The most recommended tool for this type of job is: HAKKO | Desoldering / Rework | HAKKO 808 which is rather pricey but gets the job done. Example of real word usage...

This post has been edited by lex: Feb 16 2014, 01:44 PM

Thank you for the info, and good news, I have successfully repaired one of my s750 sets! And I know how to read the connections on PCB now! It had distorted sounds before, I carefully replaced some parts, including blown diodes, one zener, some capsm and one IRF740 connected to blown diodes. Soldering on such PCB especially dealing with damaged pads is a frustrating thing, using L connections through holes, scratching solder mask then create connections, have to be very careful. Anyway, without your help, it couldn't be done, cheers!

I'm going to fix my another set with double switch on problem!
edit:
Got my meter today, looks like D9 is a bad one, no visual damage, gonna replace it. BTW, I also checked the topic on creative forum, they are pretty accurate about damaged parts.
edit2:
Replaced D9 and re-soldered those 470uf caps, everything is OK now. Once I thought I need find new replacement for my speakers, but now I have 2 sets of working S750!

I still have another question, since I haven't replaced other small caps yet. For those you mentioned choosing low impedance and/or low ESR types, how much difference is between a high one and a low one? Like for 100uf 35v, between an United Chemi-Con GXE series 340mA 320mOhm and a Nichicon PW series 555mA 117 mOhm? Do they make a big difference? What's the max acceptable impedance or min ripple current?

Thank you.

This post has been edited by chrislue: Feb 17 2014, 10:54 AM

Bad news, one of my S750 blew again, first time after I repaired it it's OK, played some music for several minutes, second time blew when doing some volume adjustments in windows . I checked it, same parts blew, a R30 resistor blew, turn to black, along with a diode d24 (a 15v zener replaced last repair), no visual damage, other parts seem ok.

What could caused this?

For those capacitors after the voltage regulators, any low impedance capacitors will do. The main purpose is to filter out remaining ripples from the voltage regulator and rectifier stage (which could have slipped the first hurdle). Those Nippon Chemi-con GXE series have higher operating temperatures (up to 125C) targeted for harsh and very hot environments such as inside car engines (and should be also suitable for this speaker system). Generally prefer capacitors that can handle high ripple currents and also low impedance as well.

Is that R30 resistor have a value of 100 Ohms? What was the wattage of the resistor and zener diodes? Do note that both resistors and zener diodes have wattage ratings. If too small wattage then it may blow (due to overheating and conducting electrical current past specifications). Check the pins at the transformer for cold solder joints. There may be a weak MOSFET in the other side/half of the circuit (which could be damaged in the first failure). Thus replace those with new ones as well. Also check that fusible link (0 Ohm resistor). Anyway, did you remove all the degraded glue and replace all the capacitors as mentioned here?

This post has been edited by lex: Feb 22 2014, 07:03 PM

Yes, R30 is a 100Ohms 1/4 W resistor, and the zener is 15v 500mW (1/2 W), should I replace R30 with a 1/2 W? I forgot to mention I also changed a mosfet IRF740 Q4 which is connected with R30 in first repair, I don't know if it is failed this time since I don't know how to check a mosfet. R3 and R32 (0 Ohm resistors) are OK.
I have removed all the glue and replaced all the capacitors, same ones you used in your repair.

Try using higher wattage parts, plus check D16, R39, C30 and C58 (replace all of them if necessary). Also on the other half, replace Q1. As for the R31 (fusible link or zero Ohm resistor), make sure it has no resistance at all (virtually zero Ohms). Do inspect carefully for possible cold/cracked solder joints on the transformer pins. Re-check the L links on the through hole repairs (make sure the top side has sufficient solder and contact with it)...

Make sure all degraded glue has been cleanly removed especially the feedback areas, and places there there are exposed traces and solder pads. Clean with isopropyl alcohol also, as sometimes the chemicals from the degraded glue breaking down may remain on the surface (will look like stains, and is usually conductive and/or corrosive!).

This post has been edited by lex: Feb 24 2014, 01:20 PM