Read Sony HCD-GX20 / MHC-GX20 Service Manual online
18
HCD-GX20
CN731
TP731:
TP connected to pin
TP connected to pin
q;
(IC751)
IC751
CN733
IC731
Adjustment Location: CD board
[CD BOARD] (Component Side)
CD SECTION
RF Level Check
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
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.
IC751 pin
q;
GND
CD board
oscilloscope
Note :
Clear RF signal waveform means that the shape “
◊
” can be clearly
distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
level : 1.4 to 2.1 Vp-p
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 10M
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.
following checks.
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