Haier 29T9D, Service Manual, Page: 44 / 73

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from (13) and (20) will be directly fed into the (12) of woofer amplification integrated circuit N610
(TDA7297); and, as for the audio signals that have gone through sound tone processing , the audio
signals exported from the (18) and (15) will be directly fed into the (12) and (4) of the sound
amplifying integrated circuit N601
（
TDA7297
）
. The external capacitors C717
（
562
）
and C714
（
562
）
of the (19) and (14) of N701
（
TDA9859
）
are used as the treble control capacitors for left and right
channels. The (31) of N701
（
TDA9859
）
is a woofer control switch.
Table 3 lists the pin function and test data of TDA9859 as the reference for maintenance. The data is
tested under the mode of 49.75MHz
，
PAL D/K and cylindrical color card, using a model FLUKE 79
Ⅲ
instrument.
Table 3
Resistance to Ground R
Pin Function
Working
Voltage
（
V
）
Forward Test
（Ω）
Back
Test
（Ω）
1 Pre-AV audio input of left channel 4.0 4.6M 3.1M
2 D-COIL 0.1 6.9M 4.9M
3 Interior audio input 4.0 4.7M 3.1M
4 Decoupling filter of power supply 7.9 9.1K 9.1K
5 Interior audio input 4.0 4.6M 3.1M
6 8V Power supply 8.0 2.8K 2.8K
7 AV audio output from right channel 4.0 6.5M 4.3M
8 Ground 0 0 0
9 Audio output from right channel 4.0 10.8K 10.8K
10 Audio input of right channel 4.0 4.6M 3.1M
11 Connecting terminal of bass control
capacitor 4.0 4.6M 3.1M
12 Connecting terminal of bass control
capacitor 4.0 4.7M 3.1M
13 Woofer frequency signal (L) 3.9 6.6M 3.9M~
14 Connecting terminal of treble control
capacitor
4.0 6.2M 4.2M
15 Audio output, right channel 4.0 8.8K 8.8K
16 Clock line of I
2
C bus 4.4 19K 17.9K
17 Data line of I
2
C bus 4.5 19K 18.0K
18 Audio output, left channel 4.0 8.9K 8.9K
19 Connecting terminal of treble control
capacitor
4.0 6.2M 4.3M
20 Woofer frequency signal (R) 3.9 6.5M 3.9M
21 Connecting terminal of bass control
capacitor 4.0 4.6M 3.2M
22 Connecting terminal of bass control
capacitor 4.0 4.6M 3.2M
23 Audio input of left channel 4.0 4.6M 3.2M
24 Audio output from left channel 4.0 10.8K 10.8K
25 Ground 0 0 0
26 AV audio output from left channel 4.0 6.5M 4.3M
27 Connecting terminal of analog. stereo
capacitor 4.0 4.6M 3.2M
28 Post- AV audio input of left channel 4.0 4.6M 3.2M
29 Connecting terminal of analog. stereo
capacitor 4.0 4.6M 3.2M
Circuit Explanation