Haier DX-RCRT20-09 Service Manual page 18

P13/SDA1
P14/SDA2
2. Analysis of common path circuits
High frequency television signals, received via an antenna (or transmitted through
a cable TV system) to the input terminal of the high frequency tuner UV101, are
processed for tuning and high frequency amplifying and mixing, then an analog IF
signal will go through the sound surface wave filter. Intermediate frequency signals will
be transmitted to (38) and (39) of IC201(R2J10165GF). The mixed signals of picture
video signals output from (34) of IC201.
3. Analysis of sound power amplifying circuits
Sound power amplifying circuits are composed of integrated circuits TFA9800J
and peripheral components. TFA9800J is an integrated electrical circuit . Information
introducing functions and testing data for TFA9800J maintenance is listed in Table 2.
Table 2
SYMBOL PIN
-INV1 1
SGND
2
SVRR
3
Out 1
4
PGND
5
OUT2 6
Vp
7
M/SS
8
-INV2
9
4. Analysis of vertical sync and vertical scan output circuits
The field sync signals segregated from compound sync signals are used to activate the
vertical frequency segregation system which commences when a set amount of vertical
sync pulse signals are tested. Of the sync pulse frequencies obtained from segregation,
some are transmitted to the vertical tooth wave generator. The vertical frequency tooth
wave, after geometric processing, is transmitted from (11) of IC201 (R2J10165GF) to (7) of
vertical scan output IC IC401 (LA9302).
Information introducing functions and testing data for LA9302 maintenance is listed in
Table 3. if a cylindrical color card is installed then a fluke III digital multimeter is used.
Table 3
SYMBOL
INPUT
SUPPLY VOLTAGE
Flyback generator
GND
Output
output stage supply
Input
2
79 I C-bus data line 1
2
80 I C-bus data line 2
DESCRIPTION
Non-inverting input 1
Signal ground
Supply voltage ripple rejection output
Output 1
Power ground
Output 2
Supply voltage
Mute/standby switch input
Non-inverting input 2
PIN DESCRIPTION
1 Inverting input
2 Supply voltage
3 Flyback generator
4 Ground or negative supply
5 Output
6 Output stage supply
7 Non-inverting input
3.52
3.85
Working
Voltage (V)
2.17
0
7.68
7.59
0
7.61
15.67
2.95
2.14
Working
Voltage (V)
2.95
31.6
4.19
0
17.57
33.05
2.95
18
10.7K
9.5K
Ground
Resistance (Ω)
27M
0
14.6K
4.72K
0
4.73K
15K
115K
27M
Ground
Resistance (Ω)
10.5K
33M
2.2M
0
10M
18M
11.85K