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Harman/Kardon Onyx Bluetooth Speaker - No Power

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    Harman/Kardon Onyx Bluetooth Speaker - No Power

    Had this speaker for a year and it recently stopped powering on.

    Tested voltage output of the wall charger and its outputting correct voltage. Checked voltage from charger at the circuit board connector and the voltage is making its way there.

    Anyone know anything about these or the issue, or what steps I could take next?

    #2
    Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

    foto's ?

    Comment


      #3
      Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

      Let me know if you need any more/specifics. Left black connector is 19v dc from the charger, the right white connector is what the battery plugs into.

      The battery is rated at 3.7v 2600mah and it seems full at 4.1v

      I'm curious isn't the charger at an output of 19v overkill for it? Or is that meant to charge it faster?
      Attached Files
      Last edited by caphair; 08-23-2015, 10:45 PM.

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        #4
        Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

        19v would be overkill (literally!) if it were connected straight to the battery but there will be some voltage step-down circuitry and a charge management circuit somewhere in between the two. There is likely also a boost converter somewhere for when it's running off battery.

        Doesn't look like there's a schematic anywhere so you'll have to do this the hard way...

        I see several possible DC-DC converter circuits there.
        One based around U702 and Q701
        Another based on U700,
        Another on U600.
        Another circuit based on U701 and Q700 it seems too.

        You will need to investigate all these and ensure they are all working. Checking voltage rails is the first thing to do when something doesn't work.
        Post part numbers on all those chips if you aren't sure what they're doing.

        I do see what might be a hole blown in Q701. You should inspect that more carefully.

        U400 is probably a microcontroller to control everything.
        The Audio Amps will be under the heatsinks. Class D ones going by all the output inductors.
        "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
        -David VanHorn

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          #5
          Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

          @Agent thank you I'll take a look later when I'm at home.

          This unit turns on by a push button that needs to be held in for 3 seconds. Not sure if that bit helps but I've always wondered exactly how buttons like that work.

          I'm curious about what you said here:
          "19v would be overkill (literally!) if it were connected straight to the battery but there will be some voltage step-down circuitry and a charge management circuit somewhere in between the two. There is likely also a boost converter somewhere for when it's running off battery."

          What's the point in all that rather than just using say a 5v charger connected more directly to the battery like in most other electronics? Why step it down, etc with added circuitry?

          Comment


            #6
            Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

            when you lower the voltage the current increases.
            also, 19v supplies are easy to get from laptop makers.

            Comment


              #7
              Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

              Originally posted by stj View Post
              when you lower the voltage the current increases.
              also, 19v supplies are easy to get from laptop makers.
              Oh right. Nice.

              If I'm to do voltage tests on those rails would voltage be present with it off or is it a thing where I need to try powering on while measuring?

              Comment


                #8
                Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                well you need voltage to test for it

                Comment


                  #9
                  Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                  Lol I wasn't sure if there'd be standby voltage at input pins regardless if it's on or not

                  Comment


                    #10
                    Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                    check what this black mark is!
                    Attached Files

                    Comment


                      #11
                      Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                      i got a nude L speaker and i took out the charging board and i use a 3.8v adapter and connected straight to the battery socket and left the battery there.

                      its running like this for half a year

                      sad part its when its charges the battery to full i have to shut it down because it goes in protection mode and stops the bluetooth.

                      the only way you can test is to go to the battery straight.

                      then trace back that charging
                      Just cook it! It's already broken.

                      Comment


                        #12
                        Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                        I believe it's charging fine the battery had a full charge. I even tried connecting external 4v from a dc power supply to the battery terminals on the board and it still wouldn't power up.

                        Comment


                          #13
                          Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                          Originally posted by stj View Post
                          check what this black mark is!
                          Just examined it closer, it's just a symbol not a burn mark.

                          There are two power connections labeled "power button a" and "b" one is high at 4.1v that drops to 3.8v when pressed and the other becomes high at 4.1v. But as soon as power button is released the values go back.

                          Comment


                            #14
                            Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                            the other becomes high at 4.1v ??

                            Comment


                              #15
                              Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                              Originally posted by stj View Post
                              the other becomes high at 4.1v ??
                              Oops! The other goes high from 0v to 3.8v

                              There's a 3.3v line on the power/volume controller board that gets 3.26v when power button pressed and even the power led goes high to 1.2v
                              Last edited by caphair; 08-24-2015, 02:33 PM.

                              Comment


                                #16
                                Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                                Originally posted by caphair View Post
                                This unit turns on by a push button that needs to be held in for 3 seconds. Not sure if that bit helps but I've always wondered exactly how buttons like that work.
                                The button is just a normal button. The microcontroller or such would wait for you to hold it for 3 seconds before triggering the power-on sequence.
                                "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                                -David VanHorn

                                Comment


                                  #17
                                  Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                                  Ok thanks. So with the tests I've just conducted, where should I go from here? Is it a mcu issue? When the power "a" is high and power "b" low at 0v and I press and hold power button "a" goes from 4.1 to 3.8v and then "b" goes from 0v to 3.8v

                                  Shouldn't "a" go to 0v when it's powered on? Rather than both being at 3.8v

                                  Comment


                                    #18
                                    Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                                    Not necessarily. There are many ways to detect a switch press, and we don't know the exact circuitry involved here.

                                    Do you know where the power button connects to physically? Is it across Points A and B, or something else?
                                    "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                                    -David VanHorn

                                    Comment


                                      #19
                                      Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                                      I did a continuity test and seems one leg of the switch connects to power "a" and another leg of the switch connects to power "b"

                                      Is that what you meant?

                                      Comment


                                        #20
                                        Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

                                        Also when I tried powering with a power supply set to 4.1v across battery terminals on the board, at first initial pressing of the power switch it draws 334ma then drops to 30ma with power button still being pressed

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