Creative Inspire Sound system T3030

Discussion in 'Technical Repair' started by gopalyajur, Jun 21, 2010.

  1. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    IC is still cool

    Sorry, 18 V between +ve supply and point 1 and 2
     
    Last edited: Jun 22, 2010
  2. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    Riffa, I have to leave now.

    Thanks for the help so far. Please do let me know what time you would
    be free tomorrow.

    Good night.


    regards,

    Gopal
     
  3. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Take ur time.
    Voltage from 1 and 2 should be referenced to ground.
    It should be 0V. If any voltage higher than this IC is faulty.
    If not.
    I have another voltage measurement, I will post it, U can do it later.
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    9,647
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    [​IMG]

    Above pic measurement is if every thing is fine.
    The mute and standby pin is marked.

    This measurement should be taken referenced to ground and after the caps has been discharged.

    Before power up connect meter between mute and ground.
    Observe the meter after powering up.
    Meter should go from 0 to any voltage above 3V or so.
    Rise is slow, as the mute pin is held low to prevent turn on noise. After a few seconds the voltage will rise as the cap connected to this pin charges, disabling the muting ckt.
    If this does not rise, then the cap needs to be changed, if cap is OK. IC is faulty. If voltage rises this area is fine.

    Next is the standby pin. This pin voltage will switch between 0V and any value higher than that, say 3V.
    When u turn off power switch this pin will also switch, putting the IC in stand by.
    If this works then on off is OK, But for this u need to disconnect that jumper at the volume control PCB, as u have bypassed the power switch.

    If everything passes, I can tell u away to test the power amp IC in circuit

    After every thing is OK, then you are having a Muting issue at the preamp stages.
     
  5. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    Thanks Riffa once again.

    1. There is no voltage across the standby and mute pins with respect to ground pin.

    2. There is also no voltage across the capacitor when the circuit is powered ON. The capacitor is fine when checked.

    3. Am just curious, why does the power LED in the remote does not turn ON.

    4. Also, as I mentioned before if I connect the output from R25 (close to C56) to the volume control switch in remote the LED turn ON. Does it mean that there is no supply to remote, which in turn does not turn on the amplifier circuit.
     
    Last edited: Jun 23, 2010
  6. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    So u are having a stand by issue.
    Checking .......i'll be back

    check the pick and post back
     
    Last edited: Jun 23, 2010
  7. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    Good evening Riffa.

    The voltage across ground pin and volume control switch is 0.78.
     
  8. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    The voltages are as follows with open switch (OFF position) in remote

    o o o o o -----> all ZERO volts!!!
    o o o o -----> 0 0 18 and 0.78 V

    with closed switch (ON position) in remote

    o o o o o -----> 0 0.5 0.01 0.5 0.21
    o o o o -----> 0 0 18 and 0.7 V
     
    Last edited: Jun 23, 2010
  9. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    Sorry, Riffa I have to leave now.
    If you have some suggestions please do let me know. I will check them tomorrow early in the morning.

    Have a nice evening.

    Regards
    Gopal
     
  10. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    [​IMG]

    See the pics damaged area.
    U have to fix it
    The red wires shows jumpers that you have to wire across the yellow circled points.
    Do it and check it, keep in mind that the IC gets the standby voltage it will heat up.

    It seems and the first jumper which connects the ground there is a low value resistor together with a decoupling cap.
    The glue you took away might have them stuck in it.
    A jumper will work, worst case will be noise picked at the audio, if this is the case that jumper have to replaced with components.

    First jump it and test it.
     
    Last edited: Jun 23, 2010
  11. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    Hello Rifa,

    The first jumper you mentioned actually had a capacitor (C53- 47nf), which broke when I tried to remove the glue. I have placed the jumper as per your suggestion.

    Waiting for your further instructions.
     
    Last edited: Jun 24, 2010
  12. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Ok then .
    If two jumpers are soldered, check for operation.
    If not working then check the standby voltage at IC pin and check if there is any voltage at the remote power switch
     
  13. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Gopal is an Indian name....what are you doing in Germany?
     
  14. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    No voltage huh!! Ok.. this is getting a bit complicated..let me check the pics again?

    Have you fixed the broken jumpers?
     
  15. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
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    yes, I did fix the jumpers.
     
  16. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    can you identify which wire is which
     
  17. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Give me the Voltages of the points shown in the pic referenced to GND
     
    Last edited: Jun 24, 2010
  18. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    Across point 1 is 0.7V

    For the transistors I dont know the pin configuration. Instead I would report the voltages in the following way

    left side transistor
    o---> 0.49 V
    o---> 0.71 V
    o---> 0 V

    Right side transistor

    o---> 0.71 V
    o---> 0 V
    o---> 0 V
     
  19. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Bingo !! you just found the problem.
    Do you know how to check transistors
     
    Last edited: Jun 24, 2010
  20. gopalyajur

    Thread Starter Well-Known Member

    Jan 3, 2010
    93
    13
    Yes, Rifa I know to check the transistors. I will check the transistor numbers and find out if its NPN. my guess would be if its NPN it would most probably connected to emitter.

    By the way brown wire is connected to last pin from left in the first row.
     
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