Some other combined television signals are connected via V205 and V206, which are
band eliminating triodes functioning as switches. When the 12 base pin of CPU has a
high electrical output level, V206 is connected using PAL system signals. When 12 base
pin has a low electrical output level, V206 is disconnected and V205 is connected for
NTSC3.58 system signals. Combined television signals will become video signals after
the wave trapper, which will adjust to the correct range through R225 (430 ) and R224
(470 ) and is then transmitted to (13) of N201 (TDA8844) through C218 (474).
Post video signals are transmitted to (17) of N201 (TDA8844) and front video signals
and Y signals from terminal S are transmitted to (11) of N201 (TDA8844) through C215
(474). C signals from terminal S are transmitted to (10) of N201 (TDA8844). Connection
2
of front AV signals and signals from terminal S are controlled by the I C serial bus
system in N201 (TDA8844).
5. Analysis of sound acoustic effect electrical circuits
Electrical circuits for sound acoustic effects processing are composed of integrated
circuits N701 (TDA9859) and peripheral components. TDA9859 is an integrated circuit
for HiFi multi audio signals from left and right tracks of terminal AV1 are added to (1)
functional TV sound acoustic effect processing, including high and bass frequency
division, stereo and surround sound. The audio signals from (55) of N201 are transmitted
through V211, then divided into two groups after the decoupling capacitor C706 (224)
and added to (3
s from (55) of N201 are transmitted through V211, then divided into two groups after the
decoupling capacitor C706 (224) and added to (3
The left and right tracks of terminal AV2 are added to (28) and (30) of N701 (TDA9859).
TV or AV audio signals are processed for acoustic effects in N701 (TDA9859), and the
audio signals from left and right tracks of (18) and (15) are transmitted directly to (12)
and (4) of the integrated circuit N601 (TDA7297) of the sound power amplifier.
Capacitors C717 (562) and C714 (562) connected to (19) and (14) of N701 (TDA9859)
control high frequency from the left and right tracks.
Information introducing functions and testing data for maintenance is listed in Table 3.
Test information is listed beneath VHFL, if a cylindrical color card is installed then a
FLUKE 79 III meter is used.
Table 3
Ground Resistance (R)
Step
Function
Working
Voltage (V)
Positive
(
¦¸
)
Negative
(
¦¸
)
1
Front AV frequency left track
input
4.0
4.6M
3.1M
2
Neutral point
0
6.9M
4.9M
3
Internal audio frequency input
4.0
4.7M
3.1M
4
Power decoupling wave
filtering
7.9
9.1K
9.1K
5 Internal audio frequency input
4.0
4.6M
3.1M
6
8V power supply
8.0
2.8K
2.8K
7
AV frequency right track output
4.0
6.5M
4.3M
18