Creative 5.1 PC speaker system stopped working

Discussion in 'Technical Repair' started by seedoflife, Apr 16, 2014.

  1. seedoflife

    Thread Starter New Member

    Feb 2, 2014
    4
    5
    Hi guys, I'm a newbie to this forum and am looking for help to find out what's wrong on a circuit. I have been using the Creative Inspire 5.1 PC speaker system for almost a decade. Sadly it stopped working about a few months back. There is a volume and bass control pod which sits on the desk, and when it stopped working, the green led light on it would not turn on.

    My knowledge in electronics is very limited, but I'm a hobbyist willing to learn. So I took it up as a project to restore this system. Over the last few months I have done the following checks on it and somehow brought it upto some stage where the green light on the volume control pod now turns on. But however, there is no sound output coming from the 5 satellite speakers or the subwoofer.

    Things I have checked and done so far include :

    • Checked the fuse on the circuit - it was ok
    • Checked the power source, which is an external transformer providing AC current at 13.5 volts @ 5 amps - both voltage and amps were good.
    • Checked the DC power conversion stage of the circuit - voltage and amps were good here as well.
    • Proceeded to check transistors, diodes and zener diodes. Found 1 shorted Zener Diode (C11) and two shorted transistors (H945) all of which were promptly replaced - However the green LED light would still not turn on.
    • Then I replaced the op amps (1 4556AD with a 4556D and 5 MC4558CNs with 4558Ds) - still no sign of green light turning on
    • I proceeded to replace the 3 volume control ICs (M51132L) and lo and behold the green light now turned ON. However there was no sound output.
    • Thinking it is something wrong with the 2 audio amplifier ICs (TDA8947J) I have replaced them as well (these were the last of the components leaving aside caps and resistors that i have not replaced on this board). Im still not getting any sound output.

    I think I have hit a wall and am scratching my head all over. Which is why I'm looking to this forum for help. I have noticed that now when I turn on the circuit the highlighted Zener Diode and 4 transistors all go hot within a minute or so (see pictures attached). This so happens to be the Zener Diode that I have replaced which was previously shorted. I am not sure what is going wrong.

    I have seen a previous thread (http://forum.allaboutcircuits.com/showthread.php?t=39747) with a similar outcome like mine - no green light and no sound. Yet somebody managed to help the OP with his problem. I wish I had that insight to figure out what's wrong here - the kind of knowledge that let you isolate areas of circuit take measurements and figure out which components were bad, rather than having to replace all of them and still get no sound output.

    thanks and regards,
    SeedOfLife.
     
    seed.helper and Metalmann like this.
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    9,647
    1,110
    Welcome. Glad I am making new members here. :)

    The knowledge I have is due to the fact that I live and breath electronics and also mainly cause I did study it. :D

    I dunno how I can make some one as good as me like you said but I am not that good. I just fix them.

    I will go thru your post and will reply. Standby
     
  3. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    9,647
    1,110
    First.
    Inspect ur Board and check and double check for solder bridges.
    You need clean the solder side of the board with a brush and mild alcohol or may be acetone.

    Remove all the IC's. This will eliminate probable shorts if there is a shorted IC. You would need to desolder the soldered ones. Keep the Amp chips desoldered. They can be soldered at the very last minute.

    Third and most important is to check the remote cable for continuity. This will always be the issue in 90% of the time. Take apart remote and check for continuity in every conductor inside the remote cable. You would need to straighten and twist the cable while checking each cable cause then the wire will break and make and show you if it indeed is OK or not.

    We will hit a dead end if the cable is faulty and you did not find. If you get careless and report the cable is OK without properly checking than I wouldn't understand what is wrong with the board.

    I need 100% assurance that the cable is OK or not.
    A faulty cable will result in.
    1. Intermittent power led turning on
    2. No sound.

    Next check if the Zener and transistors still get hot when all the IC's are out of the PCB
     
    Last edited: Apr 16, 2014
    quipu likes this.
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,430
    1,311
    Looking at the age and complexity of the circuit, and the nasty mess you made of the soldering and massive amount of work that has already been done to no effect, I would suggest scrapping it and just buying a new amp.

    Sorry to be the bearer of bad news. :)
     
  5. seedoflife

    Thread Starter New Member

    Feb 2, 2014
    4
    5
    Hey guys, update due long time. I managed to get this working. I found out the problem - it was the fault of the cable as pointed out by Rif@@.

    Not wanting to give up, i checked out the other post mentioned above and knew that I should read voltage across the board. When reading the voltage across the volume control IC (M51132L) I found that the volume pin which should be getting a voltage of between 0v and 5.2v, was getting a flat 0v, which made clear why there was no sound output. I checked the spec sheet for this IC and it was quite helpful even for a beginner like myself. I incidentally shorted output to the input and there was sound coming out which clearly indicated that this was a problem with the volume control.

    After carefully testing the cable of the volume control I found that the volume pin was shorting with the ground pin which is why the volume was always 0v. I stripped a few inches of the cable and sure enough found exposed ridges of wire due to maybe twisting and use.

    As of now the circuit is still outside for testing. Hope it works clean and clear as it used to when I re-asseblme the circuit insde the subwoofer cabinet.
     
  6. wayneh

    Expert

    Sep 9, 2010
    16,024
    6,120
    Well done!
     
  7. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Job well done.
     
  8. seed.helper

    New Member

    Mar 26, 2018
    6
    0
    Hi guys i have one of this working since 2005 and still works great... but i have an issue one of the capacitors of the board just fell off inside of the subwoofer... i heard rackling when moving the subwoofer and when i opened the subwoofer case there was loose blue capacitor in the botton of the subwoofer wood case.

    what im i doing here? i lost that capacitor long time ago and now im trying to get the schematics of the creative p5800.... i couldn't find it and saw the topside picture from the board here and i was happy

    unfortunately the resolution is low in here and JPEG compression doesn't help and i cant discover what is the value of the capacitor... this unit served me well in the past and continues to work without this.. just trying to be on the safe side

    thank you

    the problem is on that red arrow blue and white capacitor only what is that?? values please so i can buy one equal :p

    topside (1).jpg
     
    Last edited by a moderator: Mar 26, 2018
  9. seed.helper

    New Member

    Mar 26, 2018
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    Just to show what i was talking

    My board bought in May 2005...


    rsz_20180326_112142.jpg
     
  10. seed.helper

    New Member

    Mar 26, 2018
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    0
  11. wayneh

    Expert

    Sep 9, 2010
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    6,120
    It should be fairly easy to read the values printed on the capacitor.
     
  12. seedoflife

    Thread Starter New Member

    Feb 2, 2014
    4
    5
    Hi seed.helper. U r in luck cos Im still subscribed to this thread and I still have the board outside. After I had it "fixed" it worked well but there was this sudden thump of a noise I hear every time I power it down. I was worried it wud break the subwoofer coils. Im a beginner in electronics and my best way of troubleshooting is inspecting each and every component. So I took the board out, did a few more inspections to see there were some components lose without any soldering. I resoldered them back on, but I didnt find the time to put the board back in and fit the wires back. Besides, I have lost touch of speakers and more of a headphone guy now. I've replaced these with my earphones and am looking to give these away. Jus dint find the time to put it back, but now that you reminded me I will fix the board back on.

    As for your query, it's a 470uf 25v capacitor. I've attached pics as proof. If you need more info, better reply soon, cos like I said Im hoping to put the board back in the subwoofer case.
     
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  13. seed.helper

    New Member

    Mar 26, 2018
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    i dont need anything more my friend... you are the best since 2009 that this board is missing this capacitor and its allways working...

    its good stuff... thank you tomorrow will get capacitor in 9 years :D :D
     
  14. seed.helper

    New Member

    Mar 26, 2018
    6
    0
    i think the one you need to change is the big one that one is a filter if im not mistaken

    it may help or not.... but i would try it

    20180326_185251.jpg

    my headphones are Hyperx Revolver S. Check it out they are not very expensive but very good quality

    have a great day you all :D
     
  15. MrChips

    Moderator

    Oct 2, 2009
    18,378
    5,811
    The thump you hear is the output capacitor charging up. This is normal. Just ignore it.
     
  16. seedoflife

    Thread Starter New Member

    Feb 2, 2014
    4
    5
    Thanks guys for the infor to fix the "thump" and u r welcome seed.helper. But Im not interested in using these speakers anymore. I used these speakers when I had a PC with dedicated 5.1 output, but now I've moved to a laptop and love the earphone experience - good enough surround sound and can listen as loudly without disturbing others. But I liked the learning experience I got from tinkering with this board - as a beginner it was a total learning experience. Im jus looking to give it away to someone who may be using 5.1 now. As for the next learning project, I would really love to learn electronics formally and am eyeing some online courses. It depends on the time I have remaining at the end of the day.
     
    seed.helper likes this.
  17. seed.helper

    New Member

    Mar 26, 2018
    6
    0
    good luck and start to learn... :D i will continue to use my creative system for the years to come

    maybe after twenty years (2025) running (if it works that long) i try another one
     
  18. tonycstech

    New Member

    Dec 3, 2018
    1
    1
    Prasanna Nadagoud likes this.
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