No power and not charging, lots of shorted caps to ground on motherboard

How can I locate the cause of many capacitors that are shorted to ground (continuity beep on both sides of capacitors) on my Sony SRS-XB30 motherboard?

I bought 48 units of these speakers to fix and almost all of them don't power on and don't charge. Upon taking them apart and looking inside, some boards have a burnt capacitor near the battery connection inside. Simply replacing this capacitor won't fix the problem. I've checked all of the capacitors on the board and many of them are shorted to ground (both sides). How can I locate the root cause of all of these bad caps or does it sound like the motherboard is fried and no longer repairable?

Whoever had experience with repairing bluetooth speakers that don't power on and don't charge with lots of bad caps, please give me some input/advice.

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My srs-xb30 speaker recently suffered a total failure after my wife plugged in the incorrect power adaptor from my laptop. This has destroyed a chip on the mother board marked DK7b and may be related to your problem also in that nothing works without this IC being functional. I cannot locate any schematic information on this product or identify this IC to locate a suitable replacement. That's very strange that all the capacitors are shorted to ground? Where are you located? So did you pick these up at an auction and why do they all have a similar fault condition.




I'm in Idaho and I bought these at a liquidation company online. They all have the similar fault condition because, like what your wife did, the speakers may have had an incorrect power adapter and as a result, it blew something. If you apply 3.3 volts to the 3V3 power rail on the board (It's marked on the top), you can get the speaker to turn on if you press the power button but only for a certain time and then the red light flashes and the speaker turns off. You should check if 3V3 is grounded or not. If it is, something on that power rail is bad. 3V3 should NOT give you a BEEP on the multimeter. If 3V3 is grounded, It will affect other capacitors located even where the bluetooth chip is. The ,"bad capacitors" on my board are all connected to 3V3 and they are all, "shorted". On a good board, they aren't, "shorted".

I'm trying to figure the cause of this big short on 3V3. I will keep this thing updated to what I find. I'd like to mention other things but I'm limited to 1024 characters.


Thanks Edward, I will get back to this soon and check what you have suggested and let you know what I find. Yes please keep this up to date with anything new you find. I dont knw where I will find a replacement chip as I cant find reference to it anywhere on the internet. I am in Australia by the way. Cheers Tim


Looks like 2 options for repair:

1. Replace ARM IC

2. Replace burnt components at charging connector

I've spent many hours on these speakers and found that 3v3 is not getting powered on. The motherboard also has power lines inside of it. Its has 3 layers of power lines and this makes it even harder to pinpoint the failing component and where the power input is coming from. Half of the time, applying 3.3 volts to 3V3 power rail will literally burn the ARM IC. It will smoke and get really hot. The other half of the time, you can get the motherboard to power on but then red led flashes 3 times and the speaker turns off.

Im done trying to fix these.

For future reference: Whoever wants to fix these speakers, take a VERY THOUROUGH look at 3V3 power line.

It was a fun project and I learned some things about electronics repair but I dont have the knowledge of whats causing this short even though it seems like the ARM IC is shorted. Ive spent a lot of time on this and its time for me to move on another project.


Dear Edward Tsema.

I am having the same problem, my xb30 is currently losing 3.3v. This Sony I received helped my friend, my friend brought to Sony's warranty center but was returned due to misuse (using non-Sony sources). I suspect some components on the motherboard have been removed and not re-installed the same, so you can help me take pictures on both sides and then send me the photo email:

Can you explain more about the xb30 you have successfully modified, because there is no circuit diagram so the repair is extremely difficult.

Thank you very much.


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