Harman/Kardon Onyx Bluetooth Speaker - No Power

[Agent24]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

I know less about Bluetooth than you, I expect...

All I can think of are the obvious things... is power actually getting to the module? Is the module's clock crystal working? If there are any external reset or enable lines to the module, are they OK?


caphair, can you give us a closer photo of the Bluetooth module to show it better? Maybe there are components on there you could check. Knowing the code silkscreened on its board might also help, since the sticker codes don't come back to anything.

Take the sticker off and find the IC code underneath, maybe a datasheet could be found for that. Maybe...

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

First let me confess that I have no experience with Bluetooth, nor do I have any Bluetooth devices, so others may be better placed to advise you. That said, your photo isn't clear, but AFAICT the Bluetooth module consists of a receiver IC and a serial (?) flash memory IC on a daughter PCB. It would help to see what is under the sticker, but I expect that the module may be available as a generic unit for OEMs to adapt for their own use. You would then need to transfer the firmware in the MXIC chip from your Harman Kardon device to the replacement module. Depending on the manufacturer's support for the module, there may be a software tool for uploading firmware to a blank module.

There is one other possibility that comes to mind. It could be that the module is shutting down in response to an external fault. One way to test for this would be to disable the MXIC chip. This will invalidate the OEM firmware and cause the Bluetooth chip to revert to kernel mode. The chip should then identify itself via USB and prepare itself to receive a firmware upload. If the chip is still unresponsive, then this would confirm that the fault is localised within the module.

Still another check would be to test for the presence of a standby supply at one or more of the module's pins, without pressing the power button. If my analysis is correct, then I would not expect to find a standby voltage.

[caphair]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

Thanks so much for your help it was appreciated. Would I be able to find a replacement Bluetooth controller or is this a proprietary part that only the company would have?

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

Assuming you were holding down the power button, and assuming that +3.3V was present all the while that the USB test was being performed, then ISTM that the bluetooth module must be dead.

As for the supply voltages, they all seem to be where they should be. If we take the 15W power rating and compute the peak voltage required to achieve this rating in full bridge mode, we get ...

Power = Vrms x Vrms / Resistance = (0.707 x Vpeak) x (0.707 x Vpeak) / 4 ohms

So ...

Vpeak = sqrt( 15 x 4 x 2) = sqrt(120) = 10.95 volts

... which matches your measured value of 11.2V.

The BQ24090 battery charger IC has an input voltage range of 4.5V - 6.5V, so your measured value of 4.67V for the step-down converter is at the lower end of the range. This makes sense since this would result in the least input-output voltage differential for the BQ24090, which in turn would result in the lowest possible power dissipation.

The reason that I got U700 and U600 mixed up was because I was confused by your statement in post #33 when you wrote that "I noticed the top [regulator] has voltage readings while the bottom one didn't have any". It did occur to me that it would make more sense for the 3.3V regulator to be near the bluetooth and AKM chips while the 4.67V regulator should be nearer the battery charge controller. Anyway thanks for clearing that up.

As for the power button, I'm thinking that it may behave like a latching "soft" on/off toggle. The following explanation is my guess as to how it works. It may be completely wrong.

When you hold down the button, Q700 is switched on, causing U702 (+11V) and U700 (+3.3V) to come alive. The bluetooth controller (U300) then wakes up, sees that the power button is closed, and then shunts the button with a transistor switch. This transistor keeps the power switched on when the button is released. A dead bluetooth controller would explain why you can keep the regulators alive by holding down the button and why they switch off when you release it. In fact Bob Parker's ESR meter uses exactly this type of latching arrangement. See the instructions in the DSE kit for a circuit diagram:

[caphair]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

I'd be looking at the cathodes of D701 and D702 in battery mode (12V ??) and charger mode (18V).

Check the load side of the 6R8 coil driven by U600. In charger mode you should see between 5V and 6V, whereas in battery mode there should be 0V.

The load side of the 6R8 coil driven by U700 should be at +3.3V in both modes.

Check that the bluetooth module (U300) can be detected by your PC using UVCView or USBDeview. If it shows up as a Harman Kardon device, then this would suggest that it is alive and that the MXIC flash memory chip is intact. If it detects with the product and vendor IDs of the bluetooth chip, then this would point to a checksum error in the firmware or something along those lines.

Remember to press the power button.

Battery mode I measure 0v both on D701 / D702 - However, if I press the power button they both measure 11.20v and the voltage slowly drops down when power button released.

In charger mode both D701 / D702 measure a solid 18.82v and no change whether power button pressed or not.

U600 6R8 measures 3.25v in charger mode regardless if power button pressed. battery mode 3.25v only when power button pressed

U700 6R8 measures 4.67v in charger mode regardless if power button pressed. 0v and no change when power button pressed in battery mode

I think you had U600/U700 mixed in your drawing bc I seem to get values you mentioned just on opposite ICs

PC did not detect the Bluetooth module

[Agent24]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

Thanks Agent24. I was looking for "514B". <smacks forehead>

BTW, TI have a part marking lookup resource:

http://www.ti.com/general/docs/partm...hType=partmark

I think we all hate SMD IC codes...

Thanks for the link. Looks very useful. Pity all the manufacturers don't do that!

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

Thanks Agent24. I was looking for "514B". <smacks forehead>

BTW, TI have a part marking lookup resource:

http://www.ti.com/general/docs/partm...hType=partmark

[Agent24]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

I'm stumped by U702, but I'm convinced it's a boost converter. Maybe someone else can identify it. In any case I think there is enough information to locate the fault, assuming there are no errors in my layout.

Package marking S14B matches the LM3478, I think this is U702.

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

I'd be looking at the cathodes of D701 and D702 in battery mode (12V ??) and charger mode (18V).

Check the load side of the 6R8 coil driven by U600. In charger mode you should see between 5V and 6V, whereas in battery mode there should be 0V.

The load side of the 6R8 coil driven by U700 should be at +3.3V in both modes.

Check that the bluetooth module (U300) can be detected by your PC using UVCView or USBDeview. If it shows up as a Harman Kardon device, then this would suggest that it is alive and that the MXIC flash memory chip is intact. If it detects with the product and vendor IDs of the bluetooth chip, then this would point to a checksum error in the firmware or something along those lines.

Remember to press the power button.

[caphair]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

I'm stumped by U702, but I'm convinced it's a boost converter. Maybe someone else can identify it. In any case I think there is enough information to locate the fault, assuming there are no errors in my layout.

Thanks for that! So am I just looking for voltages that should be on inputs of the ics?

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

I'm stumped by U702, but I'm convinced it's a boost converter. Maybe someone else can identify it. In any case I think there is enough information to locate the fault, assuming there are no errors in my layout.

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

BQ24090, Texas Instruments, 4.45V - 6.5V in, 4.20V out, 1.0-A Single-Input, Single-Cell Li-Ion Battery Charger:
https://cdn.badcaps-static.com/pdfs/...609a177dad.pdf
https://cdn.badcaps-static.com/pdfs/...557f031697.pdf

AK7742EQ, Asahi KASEI, 24bit 2ch ADC + 24bit 4ch DAC with Audio DSP, +3.3V:


DMP3035LSS, Diodes Inc, SINGLE P-CHANNEL ENHANCEMENT MODE MOSFET, -30V, -11A:


CSD17307Q5A, Texas Instruments, 30V, 11A, N-Channel NexFET Power MOSFET:
https://cdn.badcaps-static.com/pdfs/...682ed3c199.pdf

TPS54331, Texas Instruments, 3-A, 28-V Input, Step Down DC-DC Converter With Eco-mode:
https://cdn.badcaps-static.com/pdfs/...bc7b95556e.pdf

     |------------------------------------------------|
     |   U600        U701          |
     |  .---------.    .---------.        |
     |  | step  |~5V-6V | battery | +4.20V    |
     |---| down  |--------| charger |-------|    |
     |  |converter| -->  | control | -->  |    |
     |  '---------'    '---------'    |    |
     |   TPS54331      BQ24090     |    |
     |                    |    |
     |               Bat/AC   |    |
     |               switch   |    |
     |         U702   DMP3035LSS  |    |
     | D701  D702 .---------.   Q700   |    |
     |       | boost |   _/  .-------.  |
 19VDC o-+-->|--+--|<---|converter|----o/ o--|battery|  |
        |    | 12V ? |   |  '-------'  |
        |    '---------'   |   3.6V   |
        |            |----------------|
        |    TPS54331
        |     U700       U300
        |    .---------.   .---------.
        |    | step  |+3.3V |bluetooth| .----.
        +-------| down  |------| module |--|USB |
        |    |converter|   |     | '----'
        |    '---------'   '---------'
 speakers   |      | +3.3V      |
       .-------.   |         |
    |\  |class D| .---------.      |
    | ||__| audio | |  AKM  |      |
    | || | power |--| audio |-----------|
    |/  | amps | |  chip | <-- audio
       '-------' '---------'
              U400
             AK7742EQ

[caphair]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

Hey guys thanks for the replies! Appreciate it. Finally home and can post part numbers of the ic's on the board. Let me know if you need any others from what I've listed:

U702 - 3860S14B
Q701 - CSD17307
Q700 - P3035LS
U701 - 24090
U700 - 54331
U400 - AK7742EQ

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

In the absence of further information, this is my best guess as to how the circuit works:

        U600        U701
       .---------.    .---------.
       | step  |~6V   | battery | +4V
     |---| down  |--------| charger |-------|
     |  |converter|    | control |    |
     |  '---------'    '---------'    |
     |   TPS54331     BQ24083 ?    |
     |                    |
     |               Bat/AC   |
     |               switch   |
     |         U702          |
     | D701  D702 .---------.  Q702 ?   |
     |       | boost |   _/  .-------.
 19VDC o-+--->|-+--|<---|converter|----o/ o--|battery|
        |    | 12V ? |      '-------'
        |    '---------'
        |
        |    TPS54331
        |     U700       U300
        |    .---------.   .---------.
        |    | step  |+3.3V |bluetooth| .----.
        +-------| down  |------| module |--|USB |
        |    |converter|   |     | '----'
        |    '---------'   '---------'
 speakers   |      | +3.3V
       .-------.   |
    |\  |class D| .---------.
    | ||__| audio | |  AKM  |
    | || | power |--| audio |
    |/  | amps | |  chip |
       '-------' '---------'
              U400

https://cdn.badcaps-static.com/pdfs/...3b7c29533e.pdf

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

It might be worth checking whether the device identifies itself via USB. You could use a tool such as UVCView or USBDeview for this:

http://www.nirsoft.net/utils/usb_devices_view.html
http://download.microsoft.com/downlo...31d-436b-9281- 92cdfeae4b45/UVCView.x64.exe
http://www.users.on.net/~fzabkar/USB...VCView.x86.exe

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

AFAICT, each speaker is driven from two amps in a full bridge configuration. That only necessitates a single supply, as is the case for most (?) car audio amps.

Fig 4B in the following article shows a dual supply but it could just as easily be biased for a single supply:

http://sound.westhost.com/articles/pwm.htm

In a dual supply configuration one terminal of each speaker would most likely be grounded, as in Fig 4A.

I expect that one of the "6R8" supplies would be responsible for the +3.3V rail. A continuity test between the 3.3V test point and each of the 6R8 coils would confirm this. A +/-3.3V rail could not possibly provide 15W into 4 ohms, as stated in the spec for the speakers, so this would again point to the boost converter as the supply for the power amps.

[Agent24]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

And if an amplifier needs a -Ve rail, then yes, both it and the +Ve rail need to be present at the same time, otherwise you're going to clip off half the signal at best.

[fzabkar]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

It would help a LOT if all the chip markings were listed, including those under the sticker, otherwise we're working in the dark.

That said, ISTM that the amp would not require separate B+ and B- supplies. In fact we would need an inverting regulator to generate the latter. Instead we could get by with a single, boosted B+ supply. I believe that is the function of D702, L702, Q701 and U702, ie a boost converter. R728 appears to be providing the current sensing. The cathode of D702 (C726 - C731) appears to be the boosted output voltage.

[caphair]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

Ok, suppose those circuits provide B+ and B- to the amp, would they both still be on at the same time?

[Agent24]

Re: Harman/Kardon Onyx Bluetooth Speaker - No Power

From what I see on the board, both of them have their enable pins tied through resistors to the supply pin, so they should be enabled and working as soon as they get power. If one of them is not getting power, I guess you need to trace back its power input Pin 2 and see where it gets its power from and why it's not.

Might also be interesting to try trace its output and see what it supplies.

Additionally, if you can figure out which resistors are the feedback resistors (there's an example circuit and formula in the datasheet) you can calculate what voltage it should be outputting and then check that the working one does in fact output the right voltage.