Sony HCD-HPX9 Service Manual page 56

HCD-HPX9
CD SECTION
Note:
1. CD Block is basically designed to operate without adjustment. Therefore,
check each item in order given.
2. Use YEDS-18 (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
S-CURVE CHECK
CD board
TP(FE)
TP(VC)
Procedure :
1. Connect an oscilloscope to TP (FE) and TP (VC) on the CD
board.
2. Press the button to turn the power ON.
I/1
3. Load a disc (YEDS-18) and actuate the focus search. (In
consequence of open and close the disc tray, actuate the focus
search)
4. Confirm that the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak level
within 2.0 ± 0.5 Vp-p.
S-curve waveform
Note: • Try to measure several times to make sure than the ratio
of A : B or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.
Connecting Location: CD board
RFAC LEVEL CHECK
CD board
TP(RFACO)
TP(VC)
Procedure :
1. Connect an oscilloscope to TP (RFACO) and TP (VC) on the
CD board.
2. Press the button to turn the power ON.
I/1
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check if RFAC
signal level is correct or not.
Note: Clear RFAC signal waveform means that the shape " ◊ " can be
clearly distinguished at the center of the waveform.
Connecting Location: CD board
56
Oscilloscope
symmetry
A
within 2.0 ± 0.5 Vp-p
B
oscilloscope
RF signal waveform
– CD BOARD (Conductor Side) –
TP
(VC)
TP
(FE)
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 0.7 ± 0.3 Vp-p
IC101
TP
(RFACO)