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3-8
ONE POINT REPAIR GUIDE
7. SPEAKER NO AUDIO
Speaker No Audio
7-1. AMP IC (IC700, IC701, IC705)
7-1-1. Solution
Replace IC700, IC701, 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).
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 : +66 V
pin1, 2 : +66 V
pin3, 4 : PGND
pin3, 4 : PGND
pin5, 6 : -66 V
pin5, 6 : -66 V
pin5 of ICs
pin5 of ICs
CSD
CSD
Содержание OM7550
Страница 13: ...1 12 ...
Страница 16: ...2 3 Figure 3 Step 3 Seperate Cover_Side to out direction ...
Страница 17: ...2 4 ...
Страница 21: ...2 10 ...
Страница 58: ...3 37 3 SERVO IC401 X XI XO Fig 3 2 CD 16M IC401 pin31 Fig 3 1 Crystal 16 9344 MHz X400 11 10 12 10 11 12 ...
Страница 79: ...3 75 3 76 3 MAIN VFD RMC1 P C BOARD TOP VIEW ...
Страница 80: ...3 77 3 78 4 MAIN VFD RMC1 P C BOARD BOTTOM VIEW ...
Страница 81: ...3 79 3 80 5 FRONT P C BOARD TOP VIEW 6 FRONT P C BOARD BOTTOM VIEW ...
Страница 82: ...3 81 3 82 7 TOP VOLUME_FR1 P C BOARD TOP VIEW ...
Страница 83: ...3 83 3 84 8 TOP VOLUME_FR1 P C BOARD BOTTOM VIEW ...