3-8
ONE POINT REPAIR GUIDE
7. SPEAKER NO AUDIO
Speaker No Audio
7-1. AMP IC (IC700~IC705)
7-1-1. Solution
Replace IC700~IC705 on MAIN board.
7-1-2. How to troubleshoot (Countermeasure)
1) Check supply voltage of AMP(CN110) & PWM signal
Normal supply voltage and signal
Check AMP IC.
Poor supply voltage
Check SMPS Assy.
Poor signal
Check PWM IC.
2) Check CSD of FET driver IC (IRS2092 : EAN60778301).
CSD has about 5 V on normal state.
When AMP has problem, CSD is LOW state or keep change LOW to HIGH.
7-1-3. Service hint (Any picture / Remark)
< MAIN board top view >
< MAIN board top view >
< MAIN - AMP circuit >
CN110
CN110
pin1, 2 : +58 V
pin1, 2 : +58 V
pin3, 4 : PGND
pin3, 4 : PGND
pin5, 6 : -58 V
pin5, 6 : -58 V
pin5 of IC700
pin5 of IC700
CSD
CSD
Summary of Contents for CM9750
Page 15: ...2 2 ...
Page 19: ...4 SPEAKER SECTION A60L A60R ...
Page 75: ...3 71 3 72 PRINTED CIRCUIT BOARD DIAGRAMS 1 SMPS P C BOARD TOP VIEW ...
Page 77: ...3 75 3 76 2 MAIN P C BOARD TOP VIEW ...
Page 78: ...3 77 3 78 MAIN P C BOARD BOTTOM VIEW ...
Page 79: ...3 79 3 80 3 FRONT P C BOARD TOP VIEW ...
Page 80: ...3 81 3 82 FRONT P C BOARD BOTTOM VIEW ...
Page 81: ...3 83 3 84 4 FRONT_CTRL P C BOARD TOP VIEW BOTTOM VIEW ...