Checking The Output Of Audio Signal; Checking The Reset Port - LG GoldStar DVD5185 Service Manual

11. Checking the output of Audio signal

IC401 is called as Audio DAC, DAC means Digital-
Analog Convertor.
This IC receives digital signal from MPEG and con-
vert digital signal to analog signal, so we can hear
sound...
IC401 is connected with OP - AMP and an analog
Audio signal is amplified at the OP - A MP.
because the analog audio signal from DAC is a
very low level.
DA_XCK
IC501
DA_BCK
DA_LRCK
MPEG
DA_DATA
(ZIVA5.0)

12. Checking the reset port

Pin 7 and pin 47 of IC20, pin202 of IC501 and pin 11 of IC202 are related to RESET.
We can know whether IC is intialized or not through those ports.
The waveform shows the status when the reset signal works normally.
If the /M-RESET is abnormal, then check the front u-com(IC901) and replace it
IC401
DAC
Analog
audio
IC402
OP-
AMP
The waveform when power on
DA_XCK : this is the system clock for IC401
DA_BCK : this is standard clock to synchronize the
audio serial data
DA_LRCK : R-chanel and L-chanel are selected
among the audio serial data by this
DA_DATA : serial audio data
3-7
DA_XCK
DA_BCK
DA_LRCK
DA_DATA
/M-RESET (Pin202 of IC501)
DSP_RST (Pin 47 of IC201)
/M-RESET (Pin 11 of IC202)
3.3V power input