Sony HCD-VX777 Service Manual page 18

HCD-VX777
Note: Clear RF signal waveform means that the shape "◊" can be
clearly distinguished at the center of the waveform.
RF signal waveform
E-F Balance (1 Track jump) Check
BD board
TP (TEO)
TP (DVC)
Procedure:
1. Connect oscilloscope to TP (TEO) and TP (DVC) board.
2. Turned Power switch on.
3. Load a disc (LUV-P01) and playback the number nine track.
4. Press the bB button. (Becomes the 1track jump mode.)
5. Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
1 track jump waveform
DVC
level=1.0±0.5Vp-p
6. Adjust RV101 so that A (DC voltage) becomes 0.
Checking Location:
[BD BOARD]
TP
(CE)
TP
(RFDC)
IC103
TP
(RFAC)
18
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 0.65 ± 0.15Vp-p (RFDC)
1.1 ± 0.4Vp-p (RFAC)
oscilloscope
+
–
Center of
waveform
B
A (DC voltage)
Symmetry
IC101
TP
(XPCK)
VIDEO SECTION
Frequency adjustment
1. Connect the frequency counter to check point of the VIDEO
board.
2. Adjust CT503 of the VIDEO board so that the frequency
counter read 27MHz ± 80Hz at STOP condition.
VIDEO board
(27 MHz)
Adjustment Location :
[ VIDEO BOARD ] – SIDE A –
SL501 SL502 SL503
TEST MODE
(27MHz)
CT503
VIDEO
FREQUENCY
(GND)
[ VIDEO BOARD ] – SIDE B –
SL503
TEST
IC502
SL502
MODE
SL501
frequency counter
+
–
IC505
IC507