18
CD SECTION
Note:
1. CD Block is basically constructed 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
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
Adjustment Location: BD board
Procedure :
1. Connect the oscilloscope to test points TP (FE) and TP (VC).
2. Connect TP (FEI) and GND, and TP (AGCCON) and GND of
the BD board with lead wires.
3. Press the
"/1
button to turn the set ON.
4. With the disc (YEDS-18) loaded, press the
7
button and
perform focus search. (Focus search will be performed in the
same way even while the disc table is pushed in and out.)
5. Check the symmetry and peak to peak level of the oscilloscope
waveform (S curve) at this time.
S-curve waveform
6. After check, remove the lead wire connected in step 2.
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 bright-
ness to obtain best waveform.
Adjustment Location: BD board
RF Level Check
Procedure :
1. Connect oscilloscope to test point TP (RF) and TP (VC) on BD
board.
2. Connect TP (AGCCON) and GND of the BD board with lead
wires.
3. Press the
"/1
button to turn the set ON.
4. Put disc (YEDS-18) in and playback 5track.
5. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
6. After check, remove the lead wire connected in step 2.
oscilloscope
BD board
TP (FE)
TP (VC)
+
–
oscilloscope
BD board
TP (RF)
TP (VC)
+
–
E-F Balance (Traverse) Check
oscilloscope
BD board
TP (TE)
TP (VC)
+
–
Adjustment Location: BD board
Procedure :
1. Connect oscilloscpe to test point TP (TE) on BD board.
2. Short-circuit SL502 of the video board to GND.
3. Turned Power switch on. Press FUNCTION button to select
CD.
4. Put disc (YEDS-18) in to play the number five track.
5. Press the PLAY MODE button. (The tracking servo and the
sledding servo are turned OFF.)
6. Check the level B of the oscilliscope's waveform and the A (DC
voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ± 22%
Traverse waveform
0V
level : 1.3
±
0.6 Vp-p
A (DC voltage)
Center of the waveform
B
7. Press the PLAY MODE button. (The tracking servo and sled-
ding servo are turned ON.) Confirm the C (DC voltage) is al-
most equal to the A (DC voltage) is step 7.
Traverse waveform
0V
C (DC
voltage)
Tracking servo
Sled servo
OFF
Tracking servo
Sled servo
ON
symmetry
A
B
Within 4.0
±
1.0 Vp-p
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
level : 1.75
±
0.25 Vp-p
8. Desolder the short-land (SL502) short-circuited at step 2.
Adjustment Location: BD board
Summary of Contents for HCD-LV80
Page 30: ...HCD LV80 30 30 7 5 SCHEMATIC DIAGRAM DECK SECTION See page 54 for IC Block Diagrams Page 38 ...
Page 31: ...HCD LV80 31 31 7 6 PRINTED WIRING BOARD DECK SECTION See page 19 for Circuit Boards Location ...
Page 39: ...HCD LV80 39 39 7 14 SCHEMATIC DIAGRAM MAIN 3 3 SECTION See page 36 for Printed Wiring Board ...
Page 41: ...HCD LV80 41 41 7 16 SCHEMATIC DIAGRAM POWER SECTION ...
Page 45: ...HCD LV80 45 45 7 20 SCHEMATIC DIAGRAM PANEL VR SECTION See page 55 for IC Block Diagrams ...
Page 47: ...HCD LV80 47 47 7 22 SCHEMATIC DIAGRAM TC PANEL SECTION ...
Page 51: ...HCD LV80 51 51 7 26 SCHEMATIC DIAGRAM CD MOTOR SECTION Page 38 ...
Page 52: ...HCD LV80 52 52 7 27 SCHEMATIC DIAGRAM TRANS SECTION ...