Sony HCD-HPX7, Service Manual

Page: 56 / 110

56
HCD-HPX7
CD board
Oscilloscope
TP(FE)
TP(VC)
symmetry
S-curve waveform
within 2.0
±
0.5 Vp-p
A
B
TP(RFACO)
CD board
oscilloscope
TP(VC)
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 0.7
±
0.3 Vp-p
– CD BOARD (Conductor Side) –
TP
(VC)
TP
(FE)
TP
(RFACO)
IC101
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 10M
Ω
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
Procedure :
1. Connect an oscilloscope to TP (FE) and TP (VC) on the CD
board.
2. Press the
?/1
button to turn the power ON.
3. Load a disc (YEDS-18) and actuate the focus search. (In con-
sequence of open and close the disc tray, actuate the focus
search)
4. Confirm that the oscilloscope waveform (S-curve) is symmet-
rical between A and B. And confirm peak to peak level within
2.0
±
0.5 Vp-p.
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
Procedure :
1. Connect an oscilloscope to TP (RFACO) and TP (VC) on the
CD board.
2. Press the ?/1 button to turn the power ON.
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