HCD-LX7/LX8
17
17
6-1. CIRCUIT BOARDS LOCATION
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
Procedure :
1. Connect the oscilloscope to test points TP (FE) and TP (VC).
2. Connect TP (FE1) 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
HX
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.
RF Level Check
Procedure :
1. Connect oscilloscope to test point TP (RF) and TP (VC) on BD
board.
2. Press the
"/1
button to turn the set ON.
3. Put disc (YEDS-18) in and playback 5 track.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal 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 :
[ BD BOARD ] — SIDE A —
Procedure:
1. Connect oscilloscope to test point TP (TE) on BD board.
2. Press the
"/1
button to turn the unit ON.
3. Put disc (YEDS-18) in to play the number five track.
4. Press the
HX
button.
5. Check the level B of the oscilloscope's waveform and the A (DC
voltage) of the center of the Traverse waveform.
Confirm the following:
• A/B x 100 = less then ± 22 (%)
• B = 1.3 ± 0.6 Vp-p
1 track jump waveform
E-F Balance (1 Track Jump) check
oscilloscope
BD board
TP (FE)
TP (VC)
+
–
symmetry
A
B
Within 3
±
1 Vp-p
oscilloscope
BD board
TP (RF)
TP (VC)
+
–
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.45
±
0.25 Vp-p
0V
Center of the waveform
B
Symmetry
A (DC voitage)
level : 1.3
±
0.6 Vp-p
oscilloscope
BD board
TP (TE)
TP (VC)
+
–
TP
(VC)
TP
(RF)
TP
(TE)
TP
(FE1)
TP (FE)
TP
(AGCCON)
SECTION 6
DIAGRAMS
BD board
MIC board
TC-A board
TC-B board
PANEL-FL board
PANEL-VR board
HEADPHONE board
LED board
CD MOTOR board
TABLE SENSOR board
TUNER UNIT
TRANS board
MAIN board
FRONT INPUT board
CD-R board
CD-L board
PA board
AUDIO board
LEAF SW board
SUB TRANS board (LX7)
Summary of Contents for LBT-LX7
Page 32: ...HCD LX7 LX8 31 31 6 8 SCHEMATIC DIAGRAM MAIN 3 3 SECTION See page 28 for Printed Wiring Board ...
Page 33: ...HCD LX7 LX8 32 32 6 9 SCHEMATIC DIAGRAM DECK SECTION Page 30 ...
Page 35: ...HCD LX7 LX8 34 34 6 11 SCHEMATIC DIAGRAM POWER SECTION ...
Page 39: ...HCD LX7 LX8 38 38 6 15 SCHEMATIC DIAGRAM PANEL VR SECTION See page 50 for IC Block Diagrams ...
Page 41: ...HCD LX7 LX8 40 40 6 17 SCHEMATIC DIAGRAM TC PANEL SECTION ...
Page 43: ...HCD LX7 LX8 42 42 6 19 SCHEMATIC DIAGRAM CD PANEL SECTION ...
Page 45: ...HCD LX7 LX8 44 44 6 21 SCHEMATIC DIAGRAM CD MOTOR SECTION Page 30 ...
Page 47: ...HCD LX7 LX8 46 46 6 23 SCHEMATIC DIAGRAM TRANS SECTION LX7 model ...
Page 49: ...HCD LX7 LX8 48 48 6 25 SCHEMATIC DIAGRAM TRANS SECTION LX8 model ...