Preface and symptoms
A client brought in a Creative GigaWorks S750 7.1 speaker system for repair. Main problem is the speaker system cannot be powered up at all. Usually many people would assume that it was due the fuse blown whenever their equipment lost all power, however very often that is not the case. The fuse on this speaker system is easily accessible from outside (right under the power socket) and the fuse was found to be OK. Thus the fault is definitely internal (possibly on the power supply board).

First look inside
The first thing to do is to look at the power supply board. This speaker system uses SMPS (switched-mode power supply) for all its power requirements. There are two SMPS sections on this board, one for standby power and the other for power amplifiers. As with other Creative GigaWorks series, a relay is used to switch on/off the power to the power amplifier section.


Visible signs of failed components
Right away can see those big CapXon HP series capacitors in various stages of bulging, a blown diode and lots of degraded glue (the brown stuff). The design of that heatsink towering over the capacitors would have easily caused to capacitors to bulge due to prolonged heat exposure from the toasty heatsink. Anyway CapXon is not a good capacitor brand at all and is very well known for bad capacitor problems. In fact, its very common to see failed CapXon capacitors in many electronic equipment such as computer PSUs, LCD monitors, AC-to-DC adapters, etc...


Beware of degraded glue
Thus, why repeatedly the concern on degraded glue? Because degraded glue can become conductive and creates all sorts of weird problems (including short circuits)! You can read more about it here: Conductive Glue Carnage. Thus removal of degraded glue was essential.

One of the snubber network ceramic capacitors literally cracked and fell apart into pieces when removing more degraded glue...


Degraded glue and standoffs plus GND connection equals trouble
These standoffs are connected to the aluminium heatsink and to GND rail! Thus the degraded glue around other standoffs had to be removed to prevent current and future problems.

Its also possible that the diode blew due to degraded glue plus that metallic standoff (which is connected to GND!). This is the closeup of the blown diode and the blob of degraded glue that extends all the way to the metallic standoff. This diode is in the primary high voltage section! The diode is blown to beyond recognition (very little left of the markings). Later I did found out the actual part number for this diode from schematics...


More signs of possible future problems
Simply said, more CapXon junk. These capacitors with blue sleeve are all CapXon GS series 85C general purpose type which are not really suited for SMPS (switched-mode power supply) usage. Usually for SMPS, they should be higher temperature 105C low ESR or low impedance type. How did Creative engineers get away with this? Notice those disc-shaped ceramic capacitors besides them? By using ceramic capacitors in parallel to serve/function as the low ESR side! Anyway its quite common to see this configuration in some power supplies (as a method of cost cutting).

Besides those CapXon, there were also a Su'scon SL series 85C general purpose capacitor and a S.J.E RH series 105C general purpose capacitor. Thus my recommendation to the client was also to replace/upgrade all those el-cheapo crap capacitors with high quality low ESR and low impedance capacitors suitable for SMPS.

This post has been edited by lex: Aug 12 2013, 09:35 PM

Removal of failed components and cleaning up degraded glue
All the failed components (those big CapXon HP series capacitors and blown diode) were removed and degraded glue cleaned up. Even another big CapXon capacitor (KM series) which did not show signs of bulging was removed as well for capacitor upgrade. Notice the area where the glue was removed had traces and exposed solder pads (add to that, this is the primary high voltage section)!

This is the blown diode area under the board. There were leftover solder paste on the PWM power I.C that indicates a previous repair. Also previously there was a blob of degraded glue at the standoff on the right, which I've cleaned up (ie. the previous repairer did not remove the degraded glue around that area). Notice its next to the high voltage traces and solder pads! Definite recipe for current and future disaster.

These are components (mostly capacitors and a blown diode) that were pulled out. The blown diode (broken into two pieces) is in the bottom foreground. Most of the capacitors are CapXon brand, while one of them was Su'scon brand. There was the odd S.J.E brand capacitor (small one with black sleeve) which most probably was from a previous repair.


Replacements
The capacitor replacements were all high quality Japanese capacitors (which took some time to arrive after placing the order). Both the original (blown) diode and the new replacement diode have 1A current rating. However the original (blown) diode had 400V DC blocking voltage rating, while the new diode had much higher specifications with 1000V DC blocking voltage rating.

Bought a new PWM power I.C (its a TOP243YN) for standby, just in case it was that I.C that caused the diode to blow in the first place. Already checked most of the components after the (blown) diode and they seem fine. However the state of the PWM power I.C was unknown (very difficult to check I.Cs). Also had to be wary of ceramic capacitor C6, although measures fine (on the capacitance meter), could have possible breakdown/leakage at higher voltages and cause the diode to blow (again).

Capacitor upgrade
As per recommendation, all CapXon and other el-cheapo brand capacitors were removed and then replaced with high quality Japanese capacitors...

There was another CapXon GS series 85C general purpose capacitor right next (very close) to the toasty heatsink. Thus that was replaced with a very high temperature 150C ceramic capacitor. Notice the bits of residual degraded glue sticking to some of those components on the right. This area previously also had lots of degraded glue as well (already removed and cleaned).

This post has been edited by lex: Aug 28 2013, 11:31 PM

Putting it back together
The power supply board is placed back together with the power amplifiers and interface on the subwoofer unit, ready for testing...

Another look inside the Creative GigaWorks S750 subwoofer unit. This speaker system uses a triple voice coil woofer!


Testing and its fixed!
The moment of truth! Connect the power and switch on the power switch at the back, then finally the standby LED light comes up. Pressing the POWER button and the unit is fully switched on (can also hear the relay clicked inside). Feed it with some music and ran it for hours (ie. burn-in test). This speaker system can get pretty toasty as I could feel the heat on the speaker enclosure wood surface. Eventually this speaker system has been returned to the client.

Miscellaneous
Noticed that the power amplifier boards has lots of el-cheapo crap capacitors as well. This time its Jun Fu brand. Just lots of them, big and small. More cost cutting by Creative IMHO. Replacing them would take even more time and increase the burden (due to more component upgrade cost) on the client. The glue remains white in color thus had not degraded yet (possibly a different glue than the one used on the power supply board). My conclusion at the moment is to leave it like that...


Ending notes
Another repair done, though I would consider this a little easy (although the glue removal part was a tedious task). I hope that you'll find this article interesting and informative.

This post has been edited by lex: Jul 6 2013, 01:55 PM

awesome article/review, giving hopes to every creative gigaworks 5.1/7.1 series owners

Second Creative GigaWorks S750 speaker comes in for repair
Another client (a lowyat.net forummer) brought in another Creative GigaWorks S750 speaker. The main problem with his unit was "soft" and broken/distorted bass. He had tried repairing the speaker power supply himself using this guide since he found bulged capacitors also.

Incorrect components and bad repair
Unfortunately he did not follow everything in this guide, including the replacement components used/selected. First off, the four capacitors used for the amplifier power section were 85C rated (while the original capacitors were 105C rated) and was oversized (too tall). Also note there were still degraded glue remaining as well. See image below...

The top of the capacitors not only touched the heatsink, but was also pushing/bending the heatsink backwards and stressing the MOSFETs on the heatsinks. Also do beware that this type of condition must be avoided at all costs. Primarily the electrolyte inside the capacitors will start boiling due to direct heating from contact with the heatsink. This can cause electrolyte degradation and evaporation, as well as possibly capacitor explosion since the vents on the top of the capacitors were blocked by the heatsink.

This is the view from the side below. Note the heatsink is bending backwards due to the oversized capacitors. Can also see the small capacitor which I've mentioned earlier (the first unit repaired) that was very close to the heatsink, plus still lots of degraded glue in critical areas close to the transformer there.

Having 105C temperature rating on a capacitor does not always qualify as suitable for SMPS (switched mode power supply) capacitors. These MaxCap MKR series are actually 105C general purpose capacitors. Again, these capacitors were also oversized (too wide).

Degraded glue
There were still a lot of degraded glue in areas where there are exposed solder pads and traces, plus close to those standoffs which are connected to GND. The most critical ones are in the primary high voltage section. In short, he did not follow closely my guide on repairing.


Remaining original capacitors
There were still those original CapXon GS capacitors that were 85C general purpose type. Besides CapXon there were three small Su'scon SL series capacitors (85C general purpose also). Usually I would recommend replacing them with low impedance/ESR capacitors as this speaker system uses SMPS (switched mode power supply).


This post has been edited by lex: Aug 20 2013, 10:05 PM

Component removal and degraded glue cleanup
All images are self explanatory. When removing the capacitors, I've found the solder pads were damaged (peeled and came off very easily) due to the owner's self-repair, possibly placing the soldering iron on the pads too long and did not use any solder flux for faster de-soldering. When soldering and/or desoldering always try not to heat up the board too much as it can melt the glue that held the solder pads and traces. Any jaded and dirty solder joint can take time to melt, thus always use solder flux to allow the solder to melt easily and faster.


Capacitor replacements
Just as before, all electrolytic capacitors were replaced with proper high quality ones.


This post has been edited by lex: Aug 21 2013, 03:29 AM

Subwoofer problem
The main reason the subwoofer sounded broken and distorted was that all 3 voice coils inside the 8" woofer were damaged. At first diagnostics, 2 out of 3 voice coils were dead (no connection at all). During test of the sound channels, the 3rd voice coil finally gave up. Decided remove the woofer to check. When pressing down slightly on the woofer cone can hear scratchy and scraping sounds, indicating the voice coil wires have become loose and/or broken.

Since this is a voice coil problem, and furthermore triple voice coil then its going to be very tedious and time consuming to repair (especially the coil rewinding part with multiple layers for each voice coil). I've decided to send this woofer to speaker repair specialist instead. Have other repairs to attend to also.

More problems - sound channel randomly goes off
Also noticed the sound in some of the channels randomly goes missing/gone. Looking around the audio processor board, I noticed there were signs of degraded glue on the connectors. See the images below. Even though the glue does not seem degraded, it can be very deceptive as I found out there were actually degraded glue underneath. Wiggling the cables around, I found the fault easily. Chemicals from that degraded glue vaporised by heat (generated by the power amplifiers and power supply section) during usage corroded the connectors. The pins all looks dark and not shiny at all. Its not easy to clean these oxidized connectors.


Putting it back together
The woofer was finally repaired and brought back. Time to assemble everything together.


Testing and its done.
Switch the speaker on and run feed some test audio signals to it, and the bass comes rumbling shaking everything in the room. Finally, its done.


This post has been edited by lex: Aug 21 2013, 12:35 AM

lex, have you asked if creative wanna hire you? you're definitely doing a way better job (and by that i mean they've done pretty much nothing at all lol) compared to the folks at creative

very interesting. My old Megaworks 550THX had a similar issue, apparently the blown cap spilled its guts all over the PCB...so now it's consigned to my storeroom, dunno what to do with it, with 5 excellent condition satellites, heh...

Bro,

How do you remove those glue? I seen them spread on a large surface with many components and pcb traces. Scraping them or using chemical solution?

Thanks you.

I think they already expect these not to last long, as with other manufacturers. Probably they expect the user to buy new one after the speaker is spoiled.

Which PCB? Is it the power section or the amplifier section?

Just very slowly, carefully and meticulously scrape it off. Have to be aware of components under the glue. Sometimes have to temporarily desolder the components in order to clean. Quite often very time consuming. See example below...


This post has been edited by lex: Aug 21 2013, 01:14 PM

and THATS where i don't get them, there's NO NEW ONE LOL.

the only new multi channeled 5.1/7.1 creative are releasing are their non gigaworks series which typically have shit SQ. sure, people don't generally expect SQ from multi channels/gaming speakers, and they are way cheaper than the gigaworks series, but some people (like me) who does, are just out of luck.

the only alternatives i can see are edifier (which i absolutely hate their mids, having a huge gap between highs/low freq and their sub response is quite poor although the SPL is pretty good, potentially better than creative's ) or logitech (overpriced, and the new z906 is having way too many negative feedback to my liking)

this

This post has been edited by power911: Aug 21 2013, 04:24 PM

Nowadays manufacturers try to cut cost as much as possible (just compare Altec Lansing of yesteryears with Altec Lansing today for example). Also these GigaWork and MegaWork speaker systems use multi-voice coil woofers which are rare and expensive.

The midrange depends on the design of the ampliifer system (especially the high pass filter section) and primarily the drivers themselves. For good midrange, the drivers have to be of certain minimum size (diameter) and depth. Nowadays with most 2.1, 5.1 and 7.1 systems, the drivers in the satellite speakers are pretty small. Thus many would note the missing or hollow midrange. Replacing those tiny satellites speakers with a bigger one may give you back that midrange. As for modifications, besides the satellite speakers also very much depends on the amplifier system as well. If the preamp section for the satellites has a high pass filter then you try changing its cutoff frequency. Sometimes its the satellites that determine the sound. For example, on the Edifier M3300 there are lack of high pass filters for the satellites in the preamp section, thus its the satellites that determines the midrange and tweeter frequencies.

hence you can see my reluctance in replacing my gigaworks LOL

as for the mods, sounds like a lot of work and the cost may even exceed the speakers set themselves :/

Replacing the satellite speakers are easy (a piece of cake, as one would say). But changing the cut-off frequency on the amplifier system very much depends on the design of the amplifier itself. If its a simple passive or active RC filter network then very easy (usually either resistor and/or capacitor change only). But if its controlled by a DSP in some digital systems, then its either very difficult, or just not applicable.

Lex, I stumbled on your post while trying to find anything that can help me with my own sets of these. I have a few questions.
Are there any schematics for the Amp boards?
Do you have a comprehensive component list I can use to locate replacement Capacitors (I have no electronics training but I know what looks bad)
Apart from ordering capacitors with the same uf, voltage, heat rating and dimensions I have no idea what I need.
I have my original set and over the last year have purchased 3 other sets of these because they are great (when they work)
Any guidance you can give me will be most appreciated.
Cheers
Rod

Nopes, I don't have the schematics for the power amplifier boards. Since those are BASH amplifier I.Cs, the circuit layout and components used are very straight forward (follows closely the datasheet for the BASH amplifier I.C).

All the capacitors that needs to be replaced already mentioned here (with the exception of the big ceramic capacitors at the standby power section, and the film capacitors at the main power section). Make sure get correct/proper replacement capacitors. Just replace what is required, and highly recommend replacing all those CapXon and Su'scon brand capacitors even if they still look good. Roughly...

- 4x 470uF 200V 105C, high ripple handling type (for inverter and/or ballast operation)
- 2x 330uF 100V 105C, low impedance and/or low ESR type (for SMPS operation)
- 5x 220uF 35V 105C, low impedance and/or low ESR type (for SMPS operation)
- 5x 100uF 35V 105C, low impedance and/or low ESR type (for SMPS operation)
- 1x 68uF 450V 105C, high ripple handling type (for inverter and/or ballast operation)
- 2x 47uF 25V 105C, low impedance and/or low ESR type (for SMPS operation)
- 1x 0.1uF 50V 105C, high temperature type prefered (such as ceramic) as its very close to the heatsink

Still, depending on the fault and symptoms then you have to check other parts/components as well (e.g. MOSFET failure which is not mentioned here).

Seems to be common to see this model with lots of problems. Some even tried the hair dryer treatment which I do not recommend at all, as it may eventually kill/destroy the components inside. Since you have 3 other sets to tinker with, there's a lot of room to try out and learn...

This post has been edited by lex: Aug 27 2013, 08:22 PM

Many thanks for the advice and tips, I hope I can resurrect these sets by following your guide. Wish there was a better way to remove that glue.
Cheers
Rod

Lex, in your second repair you noticed the pads were gone, how did you deal with that? I have a similar situation.
Cheers
Rod

Did you use any solder flux and/or solder paste during desoldering? What was the desoldering tool used? For the top layer, scrape a bit of solder resist off to near the hole expose some fresh copper (has to be shiny). Clean with isopropyl alcohol. With help of solder flux, put some solder on the exposed copper. Make sure the solder sticks to the exposed copper (if not then clean and try again). Make an "L" shape wire from any scrap leads (must be of good thickness). Solder one side of the "L" wire on the fresh exposed copper already tinned with solder. The other end should be through the hole. Make sure the snap-in legs can fit thru the hole with that "L" wire together. May not look pretty but gets the job done. Check the image below...


This post has been edited by lex: Sep 3 2013, 07:09 PM

I used my soldering iron and a solder sucker, but I think you're right and it got too hot. I'll follow your instructions to repad the hole.
Thanks Lex.
Oh, I just had another set of these speakers turn up. With the help of your post and a lot of luck I hope to have all four sets running again.
I'll let you know how I go.
Cheers
Rod

Remember the solder flux...

If you are going to use ceramic type for that 0.1uF capacitor, then make sure the ceramic dielectric is either NP0/C0G (most prefered but quite costly for 0.1uF radial leaded part), X7R, X8R (high temperature type which was the one used here) or U2J (new kid on the block, almost as good as C0G/NP0). Avoid those with Y5V, Z5U and X5R dielectric as their capacitance can drift wildly (very large variations) with temperature.

This post has been edited by lex: Sep 3 2013, 08:03 PM

Thanks Lex, I'll make sure to check the specs:)

Hi !
I need help.
I have a problem with Creative Gigaworks S750.
I turn button on from 230V, led turns in green - ok. At power on from remote, sistem turns on then automatic turns off. If I turns once again from remote, sistem turns on and is works normally.At these resets, audio levels is setting to default.
All capacitors from power board was checked with a ESR Meter and is it ok. No blown(balloon) capacitors.
Change only (at ESR meter it was ok):
- 4x 470uF 200V 105C
- 5x 220uF 35V 105C
- 5x 100uF 35V 105C
- 2x 47uF 25V 105C
Same problem. What could be?
Thanks !

First and foremost, did you remove the degraded glue from critical areas especially the feedback section? Also check for degraded glue on the audio processing board, in particular those that touch/adhere to the I.Cs on the PCB...

Besides the ESR reading, check the capacitance of those capacitors below 100uF. Do check that 0.1uF capacitor that is very close to the heatsink (also part of the feedback section), and recommend replacing it as well (with a better capacitor). Also what was the replacement capacitor brand and series used?

Hi!
I don't think it is from glue, because impedance measurement in hi - Mohm show me no value.
The problem was from the beginning, 4 years ago, but not agresive like now.
At that time - 2009, sistem is reset perhaps once at two months.
Capacitor 0.1 uF show me an ESR 100nF - is ok.
Audio system is protected by an UPS -APC from 2009.
Uploaded the problem on the youtube. Look at the link
www.youtube.com/watch?v=GNjoj4JKqFY

Yes or no? Did you clear/clean the degraded glue first? Here's a re-quote from my first post... And here's another user from long time ago, refer to his/her post here... Beacuse the degraded glue can create "phantom components" and/or "phantom circuits". Add to that, many test meters do not operate in the high voltage range and not at all/entire frequency ranges.

Because that capacitor is an electrolytic type plus very close to the heatsink. Not the ESR reading but the capacitance reading because its rectifying/smoothing the feedback signals from the opto-isolator. All electrolytic capacitors can vary their capacitance and ESR greatly with temperature, And usually for electrolytics, its capacitance increases and ESR decreases with higher temperatures. That's why I've asked about the smaller capacitors there, especially that 0.1uF because its part of the SMPS feedback section. Also you have not told us the brand and series of the replacement capacitors.

Doesn't matter whether there's an UPS, AVR (voltage regulator) and/or external power filter because the internal power supply already has power filter as well as inrush current protection. Looking at that video, are those volume level lights flickering?

This post has been edited by lex: Sep 9 2013, 02:22 AM

Hi !
This is the capacitor values:
4x470uF/200V 105 C, KSC
5x220uF/35V Low Esr 105C, SAMWHA
5x100uF/35V Low Esr 105C, SAMHWA
1x47uF/25V Low Esr 105C, SAMHWA

About video on youtube ... leds flickering from the frame rate processing.
I will try to remove glue with hot air.
Next week I will change: 2x330uf/100V, 68uF/450V, 100nF/50V - X7R 10% -- instead of 0.1uF/50V.
I asked a question. Can I change 2x330v/200V SAMWHA instead of 2x330uF/100V ?
Thanks!

KSC (King-Sun) and Samwha? Those are not good capacitors. Not recommended at all....

Those degraded glue are not hot glue. You have to slowly scrape them off actually.

You can use capacitors with higher voltage rating but do not use Samwha. Use original capacitors from Nichicon, Panasonic, Nippon Chemicon and/or Rubycon. Also make sure they are of the correct series also (as shown in my guide here).

This post has been edited by lex: Sep 8 2013, 11:15 PM

Hi!
I forget to tell you.... 3 months ago I hear like an explode at power on 230V but dont find no one capacitor problem. Now after clean from glue, find a capacitor 471K( ESR say 476 pF)/250V/400V without a pin. In that space it is a problem, dont know where is the second link to the capacitor. See the images. Do you have any pictures ?
Thanks!

This varistor is compatible: JVR14N471K Varistor 300V AC; 385V DC instead of 471k/250V/400V ?
This is more better: VAR10-300 Varistor:metal-oxide; THT; 300V AC; 385V DC; 470V; ±10%; 2.5kA


Attached thumbnail(s)

Remember the blown diode in my post? I've already suspected that it was due to that degraded glue. That is a safety "Y capacitor". The markings "471" denotes 0.47nF or 470pF. The "second link" is connected to the primary GND (sometimes referred to as "hot" GND), which is that through hole you've pointed out in the attached picture. For replacement, use a certified safety Y capacitor of the same capacitance (0.47nF or 470pF), and not just any plain capacitor.

Nopes! They are not the same! Inadvertantly may cause a disaster if you use it instead of a proper/correct replacement (possibly electrical shock and/or causing the mains circuit breaker to trip). Varistors are for the mains input section and there's already an existing one on that power supply board. Anyway, what's your level of electrical/electronics knowledge?

This post has been edited by lex: Sep 9 2013, 03:09 PM

The "second link" connected to the primary GND is only from the right photo ? In the left photo no second link ?
This is ok 470pF/400V capacitor, Y1, CY1Y-470P 400V instead of 471K ?

See the image below, this is from a 3rd unit that came in for repair...


If its a certified Y capacitor then it should be fine. Example of a safety X/Y capacitor here: TDK CD series...

I am learning so much here

Hi Lex !
Changed all capacitors from the power board,removed the glue, same problem. At power on from remote, relay start then stops fast.
Do you have a schematic (circuit) diagram for power board ?
Thanks.

Still using those (crappy) Samwha capacitors? How many times did the relay clicked? After the initial power on from standby, there should only be one click (to indicate the relay switching on). This relay is gets its power from the secondary side of the standby section, thus all problems should point back to the standby section. Did you remove any degraded glue on the the other boards, besides the power supply board?

Try this link here: Index of /S750 PSU/Power Supply Schematics...

This post has been edited by lex: Sep 15 2013, 01:34 AM

I remove glue from the board where there are many capacitors >30 pieces.At power 230V don't hear relay. only from power remote = 2 clicks (power on - power off , very fast). I think it is a circuit remote problem. At next power on from remote, audio sistem works normally.

This post has been edited by Galeak: Sep 15 2013, 02:04 AM

There are also glue on the I/O board (where the audio input and output connectors as well as the external control pod interface connector is located). Have you checked that one? Should be only a single click when pressing the power on from the control pod. There could be some problems either with the remote control line, standby section and/or simply a weak relay. You will need to check/monitor the control signal to that transistor controlling the relay.

This post has been edited by lex: Sep 15 2013, 02:36 AM

Hi Lex!
Transistors near the relay is ok. check the D6,D7 - BR100 = bad diodes.

This post has been edited by Galeak: Sep 17 2013, 01:45 AM

Hi lex..i do wonder where do u repair subs..dont have any idea where to repair

Just monitor the base of the transistor. If there is voltage at the base (at least 0.55V or higher) when the relay goes off (clicked for the second time), then could be the relay. Otherwise monitor the +9V rail which powers the relay (for any relatively large voltage dips when the relay is switched on) . If both turns out OK then the fault could be from the control section (mostly MCU controlled, which is much more difficult to diagnose).

For your information, I do repair speakers and subwoofers. Just PM me for details if interested...

Hi Lex !
I change the diodes D6,D7 now it is ok. Thank you very much !!!

Those are diacs actually. Never thought those on the main power section (for power amplifiers) could affect the standby functions. I guess the MCU also monitors the main power section as well. Will take note of that...

Yes. I made a mistake it is diacs. Replace 2xBR100/03 with 2xDB3.

Hi Lex !
ASUS sound cards is more better like Creative ?
ASUS Xonar D2X, 7.1 - is a good sound card ?
It is safe to use hot silicon on the capacitors?
Thanks.


Attached thumbnail(s)

Usually those ASUS cards are rated better than Creative ones. The only Creative soundcard that is considered fine (can be recommended) is the Titanium HD. Others like those from ESI Audio (which now owns AudioTrak) and Echo Audio are also recommended as they are considered HiFi and studio quality. You can also use an external DAC, either using SPDIF (optical, coaxial) or USB connection. You can try inquiring here as well: Special Interest -> Home Entertainment -> Audiophiles -> Headphone Amplifier and DAC Recommendation, portables, desktops, amps, dac, lai (Headphones)...

Can be used for ceramics, but not recommended for the "lytics" (short for electrolytic capacitors). You do not want to boil the electrolytes inside those capacitors.

This post has been edited by lex: Oct 7 2013, 03:34 PM

Lex,
Got one set of 750's going thanks to your very detailed walkthrough but have come up against a problem with another. No Power and no obvious problems on the board. When I turn it on, I get nothing, no light blink or anything that might suggest power to the box. I tried the lead, the fuse, and still nothing. I know next to nothing about what is what or how to test things, I only know if something doesn't look right replace it. Any clues what I should be doing here to diagnose it?
Cheers
Rod

The usual troubleshooting procedures, for example check for failed components and check whether there is output voltage on the secondary standby side (if none then check voltage at transformer, then if none then check voltage at primary standby side, etc... etc...)

This post has been edited by lex: Oct 17 2013, 02:38 PM

Very cool finding this thread.

Lex, you give a spec list of the capacitors to get however I didn't see a brand you recommend. Could you steer me in the direction of a brand that you think is a good quality?

Also, what type of Ceramic resistors should I get for the orange ones and the diode?

What about the Mosfets? They look kind of funky on the bottom, are they fine and just need a cleanup job or do I need to replace them as well?

Thanks for your time!

UPDATE: and I'm a dolt as I see you listed what type of capacitors you got. Where did you buy them from? I want to make sure if I buy them I get the right ones.

This post has been edited by Kahlid74: Dec 4 2013, 11:39 AM

For capacitors, look for brands like Nichicon, Panasonic (also known as Matsushita), Rubycon, Nippon Chemi-Con (also known as United Chemi-Con, formerly Marcon), and Sanyo (nowadays known as Suncon).

So far had not had to replace any resistors, except for that 0 Ohm link. As for resistors, depends on the original resistor being replaced and should follow the wattage of the original resistor (in other words, the size of the resistor determines the wattage). The diode is pretty much run-of-the-mill 1N4004, which is a very common diode.

That one very much depends on whether you're going to replace them, and/or depends on the fault/problem itself. The "funky" look is mostly leftover excess flux and not degraded glue. If any of those MOSFETs had blown/failed then you will need to replace them.

Try online stores such as RS Components, Farnell/Newark/element14, Mouser and Digikey. They are guranteed to sell original capacitors (and not those Pasar Road counterfeits).

This post has been edited by lex: Dec 4 2013, 01:41 PM

Awesome LEX, thanks so much!

What about this guy, would I need to replace it?

Just change all those 85C capacitors to ones rated for higher temperatures, such as 105C ones (as shown in my guide here). Preferable to use those with high ripple current handling and/or low ESR type, as this speaker uses switching mode power supply...

What about the guy at C52, the ceramic resistor that is chipped away on top?

That is Ceramic capacitor=) btw how can it become like that??lol

That's not a "ceramic resistor", but a ceramic disc capacitor. Just replace with another one, of the same capacitance. Usually should be 100nF or 0.1uF, 50V or higher.

Per your first post I have tracked down all of the capacitors except 2x 47uF 25V, what brand did you use for this? Here is my shopping list: Does it look right?

• - 4x 470uF 200V 105C, high ripple handling type (for inverter and/or ballast operation)
○ This one had two sizes. I chose the fatter/shorter ones. Correct choice?
○ http://www.mouser.com/ProductDetail/Panaso...%2fxKQ%252bI%3d
• - 2x 330uF 100V 105C, low impedance and/or low ESR type (for SMPS operation)
○ http://www.digikey.com/product-search/en?mpart=100ZLJ330M12.5X35&vendor=1189
• - 5x 220uF 35V 105C, low impedance and/or low ESR type (for SMPS operation)
○ I choose cut tape for these, is that right?
○ http://www.digikey.com/product-search/en?mpart=UHE1V221MPD&vendor=493
• - 5x 100uF 35V 105C, low impedance and/or low ESR type (for SMPS operation)
○ I choose cut tape for these, is that right?
○ http://www.digikey.com/product-detail/en/UPS1V101MPD1TD/493-11570-1-ND/4319749
• - 1x 68uF 450V 105C, high ripple handling type (for inverter and/or ballast operation)
○ http://www.digikey.com/product-search/en?mpart=UCS2W680MHD&vendor=493
• - 2x 47uF 25V 105C, low impedance and/or low ESR type (for SMPS operation)
○ ??
• - 1x 0.1uF 50V 105C, high temperature type prefered (such as ceramic) as its very close to the heatsink
○ http://www.digikey.com/product-search/en?mpart=AR205F104K4R&vendor=478

digikey shipping exp if i am not mistaken

exp?

This one is incorrect as its rather wider than the original. The diameter should be 22mm otherwise the capacitors will not fit together. Should be this 22mm diameter version (if using Mouser): Mouser > Passive Components > Capacitors > Aluminum Electrolytic Capacitors > Aluminum Electrolytic Capacitors - Snap In > Panasonic EET-ED2D471BA...

Incorrect one again, as the lead pitch is 3.5mm. Should get the version with 5mm lead pitch. Digikey > Capacitors > Aluminum Capacitors > UHE1V221MPD6...

Look for Nichicon HE series, like this one: Digikey > Capacitors > Aluminum Capacitors > UHE1E470MDD.

expensive...but i am not sure...

Awesome, thanks man! I'll look to place orders today. For the ceramic disc capacitor would this guy work? - http://www.digikey.com/product-detail/en/6...EDSA-ND/1545918

If you are talking about the cracked ceramic disc capcitor replacement then it would work. Like I've mentioned earlier just any 100nF or 0.1uF ceramic capacitor of 50V or higher rating can be used (even those cheaper but awful Y5V ceramics), since this capacitor is non-critical (functions as low impedance side for those original general purpose 85C capacitors). However, for the capacitor that is very close to the heatsink (which is actually part of the switched mode power supply feedback section) then stick to the capacitor I've specified (for stability reasons use either X8R, X7R or NP0/C0G ceramics).

This post has been edited by lex: Dec 6 2013, 03:45 PM

Lex, u accept repair faulty speaker? Power Studio monitor speaker.
let me know detail.. thanks.

Yups, I do repair many types of speaker systems. What was the actual brand and model (as can't find any references to the brand "Power Studio")? Also what was the problem with them? Anyway, just PM me for more details...

Sorry .. I mean is a powered studio monitor.. brand is Tannoy ... model is eclipse 8..

After looking up this model, looks to be quite a complex speaker system (even has custom software to remote control it). Possibly has integrated MCU and DSP for its crossover and external output connections. By the way, what was wrong with it? Can describe the symptoms?

Dont worry. My is older gen without Dsp. 1 time plug in power .. On.. white smoke come out... then cannot ON no more..

So I could just buy a couple of the ceramic capacitor your specified and use that for both right?

Also, Digikey is out of two of the capacitors:

So for the 5x 100uF 35V 105C, low impedence and/or low ESR type (for SMPS)
This:
http://www.mouser.com/ProductDetail/Nichic...K4y6Z7OvlMKU%3d
or this:
http://www.mouser.com/ProductDetail/Nichic...BwN1o%2f8xKs%3d

For the 1x 68uF 450V 105C, high ripple handling type (inverter/balast)
Would these work?
http://www.mouser.com/ProductDetail/Nichic...ko7RlAfp%2fg%3d
or
http://www.mouser.com/ProductDetail/Nichic...CPZDTM13hVQI%3d


This post has been edited by Kahlid74: Dec 6 2013, 11:11 PM

Sounds much like the power supply section blew, possibly some weak, failed and/or faulty components. Usually should be fixable/repairable...

Yups, can use the same capacitor (that more expensive X8R high temperature ceramic) for both.

Either ones should be fine, just different packaging from the details on the website. Another option would be Nichicon PW series (slightly higher specifications than Nichicon PS series).

Their specifications are much lower than the Nichicon CS series. Here are some similar capacitors (with way better specifications than the ones you've chosen): Mouser > Passive Components > Capacitors > Aluminum Electrolytic Capacitors > Aluminum Electrolytic Capacitors - Leaded > Panasonic EEU-ED2W680 (used in the 2nd repair) and Mouser > Passive Components > Capacitors > Aluminum Electrolytic Capacitors > Aluminum Electrolytic Capacitors - Leaded > Panasonic EEU-EE2W680 (used in the 3rd repair which was not shown here). Both of them are also high ripple current handling plus long life...

This post has been edited by lex: Dec 7 2013, 12:54 AM

All capacitors purchased, UPS ground, should get them middle of next week. Kind of excited to replace them and see where it then lies. Thank you so much for all your help on this.

So all the parts have now come in and I've begun cleaning glue areas. Two specific areas proved very difficult and unfortunately, the green came up with them. The glue was so hard/crusted that it took the green with it when it came off. Is the board still workable?

can u repair razer mako 2.1 speaker? its having clicking sound

http://www.fixya.com/support/t8840595-raze...ko_2_0_speakers

This post has been edited by stargamer: Dec 13 2013, 04:58 AM

That's typical as the chemical from the degraded glue has "eaten" into the solder resist layer (that green thingy). Usually its still workable, as long as you did not break any fine traces. Make sure those traces are still connected to each other, and check for possible shorts with surrounding copper areas (e.g. bits of copper layers pulled up and mangled). There are large areas of copper that is mostly either (hot) GND or +350VDC (or +154VDC for U.S version). Removing degraded glue from that resistor (encased in heat shrink tubing) should have been a piece of cake (and I did not have to remove that resistor) but not sure how you've gotten that "ugly" (lots of scrape marks can be seen). What tool did you use?

Yups, I can repair that Razer Mako speaker system. Have already fixed/repaired 3 units so far, and all have the same ticking sound syndrome (plus other problems).

I just used a small flat head screw driver and an Exacto knife. The exacto knife is probably what did it. I tried to be super careful but that glue, when it gets super hard like that, it won't budge.

Must have patience, padawan. As mentioned some time ago (here: Post #11), degraded glue removal can be very tedious and have to proceed slowly (and carefully/meticulously) to avoid damaging/breaking PCB traces. When using a sharp knife, try avoid directly touching the PCB (otherwise there will be deep scrape and scratch marks, and possibly damaging/breaking fine PCB traces)...

This post has been edited by lex: Dec 13 2013, 04:31 PM

Indeed. I thought I was being gently but perhaps not gentle enough.

So check this out. In the mean time, with these being kind of rare now, I purchased a "Working" Gigaworks sound system off Ebay. Upon arrival it has the exact same issue as my system which is crazy! The seller is insistent it was working when he sent it, which even if it wasn't he can throw UPS under the bus as he wants me to file a claim with them, which I did. The problem is I will not give up the boards to UPS to investigate. So we'll see where this goes.

Sooo crazy. Same exact issue, no power, no red light period. How bizarre.

hi, lex, what do you use to remove those degraded glue, they are very hard, thanks!

i think with small screw drive or penknife will do...but careful

Usually I would use a flat head screwdriver, and very rarely I would use anything sharp like a knife and/or blade. Often have to proceed slowly and carefully (bit by bit on difficult patches) thus must have patience also as you do not want to damage any fine PCB traces.

Thanks, that's what I think, really time consuming and need patience.

I have another question, are general purpose capacitors OK for the 2 capacitors of 100v 330uf? Since I can't find neither Rubycon ZLJ nor ZLH here. I have Rubycon YXA and NIPPON KMF series.

This subwoofer power supply is switched mode type, thus the filter capacitors (at the secondary output section) should have been those low ESR or low impedance type, such as those I've chosen like Rubycon ZLJ and Rubycon ZLH series. That Rubycon YXA series is a standard (general purpose) capacitors with low ripple current handling. However Nippon Chemicon KMF series would be much better as its targeted as low impedance product, and had better/higher ripple current handling than Rubycon YXA series. Anyway, Rubycon YXA should have been already EOL'ed. Are those counterfeit capacitors? Diameter and lead pitch/spacing also goes into the capacitor selection. Does those capacitors have the correct diameter (12.5mm or less) and lead pitch/spacing (5mm)?

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