Hyundai H-MS1107, Service Manual

Page: 13 / 25

Page 12
Maintenance procedure for the AF part:
Check if the IC is good or not.
Replace it with an IC of the same
model. Check if the feedback
resistor and capacitor are good or
not.
YES
YES
YES
YES
NO
NO
NO
Set again according to the disc.
Use an oscilloscope to test if the
AF waveform at the output end
is normal or not (see the attached
figure 1).
Check if there is any voltage at
the power supply feet of the
power amplifier IC. If no voltage
is found, then check the voltage
part.
Adjust the sound volume to a
moderate position and then open
the menu AF output to check if it
is correctly set or not.
Use the oscilloscope to test if the
AF signal at the O/A output end is
normal or not.
YES
Check if the waveforms of the
five data LRCK, DATA1,
DATA2, DATA3 and BCK of the
decoding IC are normal or not.
(See the attached figure 2, 3 and
4.)
The AF D/A converting IC is
broken, and replace it with an IC of
the same model.
NO
YES
NO
Insert a corresponding AF signal
line and then use a testing disc to
test the sound.
Use the oscilloscope to test if the
played AF signal waveforms at
the input and output ends of the
power amplifier are normal or
The played AF part is good. The
problem is in the preceding
stage, that is, the decoding
board.
Use the testing disc to read and
release sound, and then use an
oscilloscope to test if the AF
signal is normal or not.