Haier 29T9D Service Manual page 44

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 79Ⅲ
instrument.
Table 3
Pin Function
1 Pre-AV audio input of left channel
2 D-COIL
3 Interior audio input
4 Decoupling filter of power supply
5 Interior audio input
6 8V Power supply
7 AV audio output from right channel
8 Ground
9 Audio output from right channel
10 Audio input of right channel
11 Connecting terminal of bass control
capacitor
12 Connecting terminal of bass control
capacitor
13 Woofer frequency signal (L)
14 Connecting terminal of treble control
capacitor
15 Audio output, right channel
16 Clock line of I
17 Data line of I
18 Audio output, left channel
19 Connecting terminal of treble control
capacitor
20 Woofer frequency signal (R)
21 Connecting terminal of bass control
capacitor
22 Connecting terminal of bass control
capacitor
23 Audio input of left channel
24 Audio output from left channel
25 Ground
26 AV audio output from left channel
27 Connecting terminal of analog. stereo
capacitor
28 Post- AV audio input of left channel
29 Connecting terminal of analog. stereo
capacitor
44
2
C bus
2
C bus
Working Resistance to Ground R
Voltage Forward Test
（V）
（Ω）
4.0 4.6M
0.1 6.9M
4.0 4.7M
7.9 9.1K
4.0 4.6M
8.0 2.8K
4.0 6.5M
0 0
4.0 10.8K
4.0 4.6M
4.0 4.6M
4.0 4.7M
3.9 6.6M
4.0 6.2M
4.0 8.8K
4.4 19K
4.5 19K
4.0 8.9K
4.0 6.2M
3.9 6.5M
4.0 4.6M
4.0 4.6M
4.0 4.6M
4.0 10.8K
0 0
4.0 6.5M
4.0 4.6M
4.0 4.6M
4.0 4.6M
Circuit Explanation
Back
Test （ Ω）
3.1M
4.9M
3.1M
9.1K
3.1M
2.8K
4.3M
0
10.8K
3.1M
3.1M
3.1M
3.9M~
4.2M
8.8K
17.9K
18.0K
8.9K
4.3M
3.9M
3.2M
3.2M
3.2M
10.8K
0
4.3M
3.2M
3.2M
3.2M