Hi, this is my first post. I just started to learn electronics repair from YouTube videos with no prior electronics background.
I am attempting to fix a Polk Woodburne Bluetooth speaker that would not power up due to a short circuit, as a learning project. With a dim bulb connected, I can power up multiple times without touching/changing anything, and get intermittent shorts. When it does not short, the speaker will work flawlessly until I either restart or put into standby and reawaken, and the intermittent shorts continue. In standby mode, which uses 5V power, I get no shorts. I have changed the amp power section capacitors in vain. Will try the power supply capacitors for 30V supply once I get the parts. I have also checked connections to speakers etc and all seem fine. Am I on the right track? Also, Google for schematics have not been successful, not that I would be able to properly understand anyway 😅. Thanks!
I am attempting to fix a Polk Woodburne Bluetooth speaker that would not power up due to a short circuit, as a learning project. With a dim bulb connected, I can power up multiple times without touching/changing anything, and get intermittent shorts. When it does not short, the speaker will work flawlessly until I either restart or put into standby and reawaken, and the intermittent shorts continue. In standby mode, which uses 5V power, I get no shorts. I have changed the amp power section capacitors in vain. Will try the power supply capacitors for 30V supply once I get the parts. I have also checked connections to speakers etc and all seem fine. Am I on the right track? Also, Google for schematics have not been successful, not that I would be able to properly understand anyway 😅. Thanks!
An electronic system rarely has intermittent shorts.
A more accurate description will be useful.
And Bluetooth speakers are very cheap to make, so the requirement of repair is not worth the hassle.
In many cases, the equipment is built to price, and not intended to be durable, just enough to get past warranty.
I expect that the unit is made abroad by a contractor for Polk, and may not be as well made as could be, $600 list is steep, there are much cheaper options available from Korean and Indian sellers here.
The circuit will have a Bluetooth / USB / optical receiver connected to an amplifier, which powers the speakers, and a battery charging system.
Some of those functions are on ASICs, difficult to get except in OEM quantities.
Here Bluetooth / FM /USB modules sell for $1.50, and they work on +5V supplies.
In any case, even if you find the fault, replacing parts will be difficult, unless it is capacitors and resistors.
Good luck on that.
A more accurate description will be useful.
And Bluetooth speakers are very cheap to make, so the requirement of repair is not worth the hassle.
In many cases, the equipment is built to price, and not intended to be durable, just enough to get past warranty.
I expect that the unit is made abroad by a contractor for Polk, and may not be as well made as could be, $600 list is steep, there are much cheaper options available from Korean and Indian sellers here.
The circuit will have a Bluetooth / USB / optical receiver connected to an amplifier, which powers the speakers, and a battery charging system.
Some of those functions are on ASICs, difficult to get except in OEM quantities.
Here Bluetooth / FM /USB modules sell for $1.50, and they work on +5V supplies.
In any case, even if you find the fault, replacing parts will be difficult, unless it is capacitors and resistors.
Good luck on that.
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You can search for Bluetooth receiver and Class D module, to learn how they work.
And the price as well.
And the price as well.
Yah, it is already more than 5 years old. However, it did cost USD 600. I thought it would be a good first project.
https://www.pcmag.com/reviews/polk-audio-woodbourne
Guess I will still go ahead to replace the power supply capacitors plus inspect for poor solder joints. Thanks for the reply!
Yes. When it does that and I press standby, bulb goes dim. On pressing again to wake, again intermittent bulb will light. Hope this clarifies. Thanks for your help!
If the power supply is a separate board or at least clearly delineated and the outputs are labelled or can be measured, it may be possible to replace the power supply or fit an external power supply.
Actually repairing the power supply would require an experienced technician.
Actually repairing the power supply would require an experienced technician.
I feel a new large lithium battery rigged to an external charger would work well.
A laptop battery, for example.
Or a proper number of 18650 cells in series.
A laptop battery, for example.
Or a proper number of 18650 cells in series.
So does the power supply short when not connected to the rest?
Is the fault in the power supply or in the connected circuitry?
Can you disconnect the 30V supply only?
Is the fault in the power supply or in the connected circuitry?
Can you disconnect the 30V supply only?