pearlpalms / zk-tb21_bluetooth_remove

How to remove bluetooth from ZK-TB21 or ZK-MT21

How to remove bluetooth from ZK-TB21 or ZK-MT21

ZK-TB21 is 2.1ch power amplifier.

ZK-MT21 is 2.1ch power amplifier.

Bluetooth chip is JL AC23BP. No datasheet available.

Remove the chip from the board.

Removed IC.

Short the power signal.

short IC pin No 6 and C9.

Pin 6

<-- short -->

C9

* M5350B regulator is MST5350BTS. 35v to 5v.

Bypass audio signal.

short C2 and C15. Left audio channel signal.
short C3 and C17. Right audio channel signal.

C2	<-- short -->	C15
C3	<-- short -->	C17

Board with Bluetooth removed.

AC23BP chip pin layout

AC23BP
1	unknown	24	unknown
2	unknown	23	unknown
3	unknown	22	unknown
4	unknown	21	unknown
5	unknown	20	unknown
6	Power signal	19	unknown
7	R signal out	18	Vcc
8	L signal out	17	unknown
9	unknown	16	unknown
10	unknown	15	unknown
11	GND	14	L signal in
12	unknown	13	R signal in

Cheat sheet

Pin 6	<-- short -->	Pin 18
Pin 7	<-- short -->	Pin 13
Pin 8	<-- short -->	Pin 14