LG MUSICflow SJ6 Service Manual page 41

2. NO SOUND
2-1. BLUETOOTH
2-1-1. Solution
Replace MAIN board.
2-1-2. How to troubleshoot (Countermeasure)
1) Please check status of Bluetooth cable connection. (at CN104 and BT module)
2) Please check 3.3 VA (at pin1 of CN104).
If 3.3 V is OK, please check BT_RST, BT_UART_RX,BT_UART_TX, BT_SCL, BT_SDA (pin2, 4, 11, 12).
If no signal, please replace MAIN board.
2-1-3. Service hint (Any picture / Remark)
 
ONE POINT REPAIR GUIDE
< MAIN board top view >
 
CN104 CN104
3-8