Bluetooth circuit gone bad

Thread Starter


Joined Jan 22, 2018
Have this mp3 Bluetooth player that connects with mobile devices. Problem is that it does not produce sound from the inbuilt speakers but the headset jack works fine. Inbuilt speakers are in good conditions and works when switched to Radio. "The Bluetooth device is ready to pair" only works with the headphone jack. What could be wrong? Attached is the circuit.



Joined Mar 10, 2018
Headphone jack contacts for enabling speakers bad/oxidized/dirty ?

Eg. when you plug in headphones does that normally disable the speakers ?

Regards, Dana.


Joined Jan 21, 2019
Why does it look like some of the pads are missing wires. Such as S- (I believe this is one of the speaker wires) and B- (battery?) looks like an IC design so if something is wrong inside of of those it would be a replacement. Do you have an oscilloscope? Best way to go about it is to check all the power routing which I assume mostly works since your headphones work...but you speaker side needs more power and may have separate supply. Then signal tracing. Unless you can get a schematic for this exact device you will have to reverse engineer it. Sometimes it just isn’t worth the work. Other times you may find some glaring issue.