3-10
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Only for training and service purposes.
ONE POINT REPAIR GUIDE
5. NO SOUND
There is no sound output by DIGITAL AUDIO AMP DAMAGE, repair the set according to the following
guide.
5-1. DIGITAL AUDIO AMP DAMAGE
5-1-1. Solution
Replace MAIN board.
5-1-2. How to troubleshoot (Countermeasure)
1) Check PWM_FL±, PWM_FR± & PWM_SW± signals from IC601 to IC701 & 702 each input function.
If no signal, check if I2S audio signals are entered to IC601.
2) Check PVDD.
If PVDD is abnormal, check the SMPS.
3) Check AMP_12V for driving the gate of AMP IC.
a. All the powers are normal, but if AMP_12V is low, there is possible for AMP IC to be damaged.
b. Remove L706, L707 one by one.
When removed a inductance, if AMP_12V is recovered, the IC connected to it was damaged.
c. Replace the IC with a new one.
4) Check the impedance between IC701_OUT_A/OUT_B & GND.
a. If the impedance is 0 Ω, the IC must be damaged.
b. After removing the heat sink, replace it with a new one.
5-1-3. Service hint (Any picture/ Remark)
B
R611
R617
R621
R624
R625
R626
R627
R628
R629
R247
R248
R250
C612
C613
C615
R5E9
R471
R472
R473
R474
R475
R712A
ZD702
L308
Q709
C480
C2C11
L706
L707
IC601
R702
R710
R328
R329
R712
R723
R726
R729
R730
R733
R734
R735
R736
R737
R738
R739
R740
RA601
C705
R741
R742
R743
R744
C713
R757
R75
C721
R7
C731
C732
C735
C736
C351
C739
C353
C740
C359
C741
C742
Q207
Q208
C752
L205
D701
D703
C765
C766
C388
C775
C776
C390
C778
C391
C779
C7
IC701
C7
< MAIN board top view >
IC701
L707
L706
IC601
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