Sony HCD-GTR888 Service Manual ▷ View online
17
(1) When open the tray and close it after put the disc on , it checks if
the optical block stays at innermost position by the LIMIT switch
signal. If it isn’t at innermost position, the DRIVER IC(IC201) is
controlled by DSP IC (IC101) outputs FMO signal. The signal
output from SL+/SL-terminal of DRIVER IC enables the Sled Motor
to rotate so that the optical block moves to innermost position.
(2) The DRIVER IC is controlled by
DMO
signal
of DSP IC
to give the
Spindle Motor spin a few times at the SP+/SP- terminal of DRIVER
IC.
(3) Meanwhile ,the DRIVER IC is controlled by
FOO signal
of DSP IC
and
focusing of the optical pickup is executed at the FCS+/FCS-
terminal of DRIVER IC.
(4) The CD’s Laser Diode of the optical pickup is flashed by LDO1
output of DSP IC.
(5) After detecting the reflection from the disc, the output signal from
the optical block is detected at each terminals of DSPIC( RF_A -
RF_F), and then produces the servo error signal.
(6) Based on the signal, outputs the Focus /Tracking Control
Signal ,and drives a DRIVER IC, then performs the Focus
/Tracking Servo of the optical pickup.
(7) If the playing position is not traceable by the tracking servo,
controls the DRIVER using the FMO signal of DSP IC ,and then
rotates the Sled Motor by the DRIVER output for the sled operation.
Page
18
(8) The
disc signal which is read out by optical pickup is
input to RFIP
terminal of DSP IC and converts into an audio signal inside.
(9)
The Audio signal which is converted by DSP
IC, outputs the
INPUT
SELECTOR ELECTRICAL VOLUME(IC806)
via AYNCHRONOUS
SAMPLERATE CONVERTER(IC4607), AUDIO DSP(IC4605), STEREO
D/A CONVERTER(IC4602).
<Note>
*1. The EEPROM (IC102) on the DMB21 BOARD is wrote down the
special information in the state of the substrate, therefore it
cannot supply with single IC. If the EEPROM is broken, replace
the whole DMB21 BOARD.
Page
19
Following are descriptions of the Class D Amplifier section.
Page
20
The amplifier circuit consists of three portions.
1. The PRE AMP for volume control
2. The POWER AMP which is converted an analog signal to PWM.
3. The POWER AUDIO DRIVER (MOS FET)
It calls as the CLASS D AMP combining the part of the POWER
1. The PRE AMP for volume control
2. The POWER AMP which is converted an analog signal to PWM.
3. The POWER AUDIO DRIVER (MOS FET)
It calls as the CLASS D AMP combining the part of the POWER
AMP and the POWER AUDIO DRIVER.
< The flow of an audio signal >
(1) The disc signal which is read out by BU block is input to DSP
IC(IC101), and then converts to audio signal.(Refer to 6-1-2(8))
(2) The audio signal which is output from DSP IC is input to INPUT
SELECTOR ELECTRICAL VOLUME(IC806)via AYNCHRONOUS
SAMPLERATE CONVERTER(IC4607), AUDIO DSP(IC4605),
STEREO D/A CONVERTER(IC4602) (Refer to 6-1-2(9))
(3) The control signal is input from SYSTEM CONTROLLER to INPUT
SELECTOR ELECTRICAL VOLUME and the volume control of an
audio signal is performed inside and each signal for
FRONT/SATELLITE/SUBWOOFER is output to CLASS D AMP
side.
(Refer to 8-1(4))
(4)The POWER AMP (IC4901) in the CLASS D AMP outputs the
(4)The POWER AMP (IC4901) in the CLASS D AMP outputs the
speaker signal for SUBWOOFER.
Page
Click on the first or last page to see other HCD-GTR888 service manuals if exist.