Sony HCD-GX40 Service Manual page 18

HCD-GX40
CD SECTION
Note :
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (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.
RF Level Check
CD board
IC751 pin q;
GND
Procedure :
1. Connect oscilloscope to pin q; (IC751).
2. Turned Power switch on.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
Note : Clear RF signal waveform means that the shape " ◊ " can be clearly
distinguished at the center of the waveform.
RF signal waveform
Adjustment Location: CD board
[CD BOARD] (Component Side)
CN731
18
oscilloscope
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.4 to 2.1 Vp-p
IC751
IC731
TP731:
TP connected to pin q; (IC751)
CN733