Speaker Output - LG BH4120SN Service Manual

4. NO SPEAKER OUTPUT
When unit is connected to Speaker using speaker cable, no speaker output.
4-1. AMP BOARD
4-1-1. Solution
Replace AMP board.
4-1-2. How to troubleshoot (Countermeasure)
1) Check voltage at CN601.
- If 36 V,14 VA, 3.8 VA voltage doesn't come out, re-soldering pin CN601.
2) Check voltage at IC700, IC701.
- If 36 V, 12 V voltage doesn't come out, check IC600 and SMPS board.
3) Check the AMP_SD signal of pin22 at CN600.
- If this pin is low, replace IC700, IC701.
4) If problem still occurs, replace AMP board.
4-1-3. Service hint (Any picture / Remark)
CN600 pin22
14 VA
36 V
3.8 VA
ONE POINT REPAIR GUIDE
< AMP board top view >
2-39
IC600