Theoretical questions - eTechnophiles Forum

Bluetooth Speaker won't turn on

servitec — Tue, 20 Jan 2026 07:00:52 +0000

I know is not probably the best place for a newbie, the AI somehow helps but I definitely prefer go with the experts. I am fascinated with the laws of electronic, but more than ever I know it demands a serious compromise to enter this amazing world.

Board Description: HXYT-A0-665-REV1.1 (A bluetooth speaker)
The speaker wont turn on, is doing nothing.
SIDE A
Compt.1= 56HS5, B310B (5 pins)
Compt.2= J6 (3 pins) ?
Compt.3 4004A, 33580KM
Side B
Compt.1= 4R7 (inductor)
Compt.2= SS54 (SCHOTTKY BARRIER RECTIFIER)
Compt.3= M8889, Y4D371 (8 Pins) ?
Compt.4 PNSA15E7E, X0B253, 2359

--When connected the battery in the terminals, it shows normal (aprox 5V)
--I tested the negative and positive spots in reverse of battery connector and off course no shorted
--When first tested pin C of power button, it shows 0.840V, after some tests is showing 2.4V when first push the power button it drops to 0V but now no more drops and it gets 2.4 V no matter if push the power button
--Tested all capacitors of Side A and all of them are ok, also the capacitor X which is connected to the Compt.3, the component 3 seems to be a DC-DC converter, the capacitor X is in parallel of pins 4 and 6. When checking the VIN in Compt.3 (pin5) is ok, but when I push the power button there is no VOUT (pin1)
--When connected to the charger, the device’s charging led turns on and the board battery terminals shows the charging voltage.

In Side B

We can see the battery port, the left pin is the + one, that pin goes to the compt.1 through pad named in the image as “pad positive pin”, then the compt.1 is connected to the compt.2 (I tested both and they seem to be ok). I tested all capacitors in Side B, all of them are ok except capacitor X. The capacitor X is connected to the pin that is marked with a yellow face sticker in compt.4, and I'd like to have the PCB's information or at least the compt.4's (or the M8889) in order to know that capacitor values.
What more testing do you recommend me to apply, what is component 2 in side A, what is component 4 in side B, is it a multiplexer? What is component 3 in side B, is it a switch IC? What recommendations can you give me when is hard to find a component by its code?

Side-A.jpg

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