DOWNLOAD Sony SCD-XB780 Service Manual ↓ Size: 6.17 MB | Pages: 84 in PDF or view online for FREE

Model
SCD-XB780
Pages
84
Size
6.17 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
scd-xb780.pdf
Date

Sony SCD-XB780 Service Manual ▷ View online

16
SCD-XB780
Measured Items
Specified value
RF AVRG (ADJ)
8Ch to ABh
VC AVRG (ADJ)
1F7h to09h
FE  AVRG (ADJ)
(1) CD
1EEh to 12h
(2) SACD
1F1h to 0Fh
TE AVRG (ADJ)
1E2h to 1Eh
TRVS PP (ADJ)
45h to 73h
FCS GAIN
10h to 60h
TRK GAIN
10h to 60h
(1) CD
C1
20 or less
ERROR RATE
C2
0
(2) SACD
PI1 NUM
100 or less
PI1 FRAME
5 or less
PSP AMPLITUDE (SACD only)
1000 to 4000
1-LAST TRK SEK
3500 or less
Hexadecimal (hex) display 9 bit data
FF
011111111 (+255) 
FE
011111110 (+254) 
(+) Side
(-) Side
MAX
01
000000001 (+1) 
00
000000000 (0) 
1FF
111111111 (-1) 
101
100000001 (-255) 
100
100000000 (-256) 
Hexadecimal (hex) display 8 bit data
7F
01111111 (+127) 
7E
01111110 (+126) 
01
00000001 (+1) 
00
00000000 (0) 
02
00000010 (+2) 
FF
11111111 (-1) 
FE
11111110 (-2) 
81
10000001 (-127) 
80
10000000 (-128) 
MIN
0
Specified Value:
Specified value used for OK/NG judgment when executing 92. SET CHECK
tAUTO CHECK SP?
Note:
 The specified values attached with “h” are hexadecimal numbers, and others are decimal numbers.
RF, VC, FE, and TE measured values are hexadecimal data with positive and negative signs. When comparing the measured
value with the specified value, refer to the following.
17
SCD-XB780
4-4. SACD (DL) DISC OPERATION CHECK
(• Perform as necessary)
This checking performs the focus jump using a DL disc, which is
a dual-layer HD disc, to verify the stability of the set.
A set of layer 0 most-outside track access (only once)
tone-second
trace
tfocus jump (layer 0t1)tone-second tracetfocus jump
(layer 1
t0)  are repeated 5 times.
Checking Method:
1. After setting the test mode, rotate the 
[        AMS        ]
 dial to
select “91 FJUMP CHECK” and press the 
[        AMS        ]
 dial
to enter.
2. The tray will open automatically, and then set the DL disc.
3. With “DISC IN&JOG ON” displayed, press the 
[        AMS        ]
dial.
4. The tray will be loaded in automatically, and then the test will
start.
5. During the test, “NOW TEST
iiii” is displayed.
6. Upon successful completion of the check, “OK!” will be
displayed and the tray will open automatically.  (In case of
NG, “NG! ERR FJ-UP” or “NG! ERR FJ-DWN” is displayed)
7. Take the DL disc out and press the 
[OPEN/CLOSE    ]
 button,
and the test mode selection display will be back
4-5. SHIPPING MODE
The repaired set must be initialized, and for this purpose the set
should be set to the shipping mode.
Setting Method:
1. After setting the test mode, rotate the 
[        AMS        ]
 dial to
select “8D SETUP MODE” and press the 
[        AMS        ]
 dial
to enter.
2. “INITIAL OK” is displayed and the test mode selection display
will be back immediately.
“8D 000000000 00” will be displayed, and if the scroll starts in
the left direction, the set initialization has completed
3. Press the 
[POWER]
 button to turn the power off.
The following setups are established in the shipping mode
1. Initialization of EEPROM (IC903)
• PLAY MODE
CONTINUE
• LAYER SELECT
SACD
• M/2CH SELECT
MULTI
• 2ch SPK MODE
2ch DIRECT
• Mch SPK MODE
Mch DIRECT
• Resetting the cumulative light emission time of the laser
Note
: Even if the shipment mode setting mentioned above is made, the
disc check threshold value attained in the 3. SET CHECK is not
cleared.
2. The optical pick-up moves to the home position (most-inside
track)
Error List
Display
Description
Toc Error *
Error during the time from auto adjustment to TOC
reading, Different type of disc (Such as a DVD disc),
Disc is dirty
Toc Error **** Illegal SACD (Such as a pirated version)
4-6. WAVEFORMS CHECK
BU Electrical Adjustment Mode
The BU electrical adjustment mode is used to check the S curve
waveform, traverse waveform, RF waveform, and CLV jitter. After
a disc is placed on the tray, each time the 
[        AMS        ]
 dial is
pressed, the check mode is switched in order for S curve
waveform
t traverse waveformtRF waveformtCLV jitter (for
the CD).
S Curve Check
Connection:
Checking Method:
1. After setting the test mode, rotate the 
[        AMS        ]
 dial to
select “9C. BU DENCHO” and press the 
[OPEN/CLOSE    ]
button. Place the test disc (PATD-012 or YEDS-18 or SATD-
S5 or SATD-S4) on the tray and close the tray, then press
the 
[        AMS        ]
 dial.
2. At the completion of disc type check, “CD DETECT” will be
displayed (for PATD-012 or YEDS-18).
Note:
 For the  SATD-S5 or SATD-S4, “SL DETECT” is displayed.
3. Press again the 
[        AMS        ]
 dial, and the S curve waveform
check mode will become active and “S-CURVE MODE” will
be displayed.
4. Connect an oscilloscope to the TP506 (FE) and TP504 (AVC)
on the MAIN board.
5. Check that the level A and B of waveform on the oscilloscope
satisfy the specification.
Specified Value:
Disc
A
B
SATD-S5 or
SATD-S4
PATD-012 or
0.7 to 1.7 Vp-p
–0.1 to +0.1V
YEDS-18
Note:
For easier observation of this waveform, extend the sweep time
and raise the brightness.
Checking and Connecting Location : See page 19.
MAIN board
TP506 (FE)
TP504 (AVC)
+
oscilloscope
A
B
S curve waveform
VC
l
L
l
L
l
L
l
L
l
L
l
L
A
A
l
L
l
L
l
L
18
SCD-XB780
RF Level Check
Connection:
Checking Method:
1. Under the condition of traverse waveform check mode in step
4, press the 
[        AMS        ]
 dial.
2. Connect an oscilloscope to the TP703 (RFAC) and TP704
(AGND) on the MAIN board.
3. After “WAIT” is displayed, the RF waveform check mode will
become active and “PLAY 5th TRACK”  (for the SACD, “RF
MODE ON”) will be displayed, and the 5th music on the disc
will be played.
4. Check that the RF waveform is clear and the level satisfies the
specification.
5. Press the 
[        AMS        ]
 dial (for the SACD, “RF JITTER
(5th)” will be displayed, and further press the AMS dial), and
“OUTSIDE TRACK” will be displayed and the outward track
of the disc will be played.
6. Check that the RF waveform is clear and the level satisfies the
specification.
7. Press the 
[        AMS        ]
 dial, and “INSIDE TRACK” will be
displayed and the inward track of the disc will be played.
8. Check that the RF waveform is clear and the level satisfies the
specification.
9. After checking, press the 
[        AMS        ]
 dial, and the test is
over when “BU MEASURE” is displayed.
10. Press the 
[OPEN/CLOSE    ]
 button to open the tray, and re-
move the test disc.
11. Using each type of disc, repeat from step 1 of S curve wave-
form check up to step 10 of RF level check.
12. When the check is over, press the 
[POWER]
 button to turn the
power off.
Note:
 Take care not to leave the test disc in the set.
Specified Value:
Disc
A
SATD-S5 or
SATD-S4
PATD-012 or
0.9 to 1.4 Vp-p
YEDS-18
Note:
 Clear RF waveform refers to the waveform where 
◊ shapes should
be distinctively observed in the center.
Checking and Connecting Location : See page 19.
MAIN board
TP703 (RFAC)
TP704 (AGND)
+
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
RF signal waveform
A
l
L
l
L
l
L
l
L
A
Traverse Check
Connection:
Checking Method:
1. Under the condition of S curve waveform check mode in step
5, press the 
[        AMS        ]
 dial.
2. After “WAIT” is displayed, the traverse waveform check mode
will become active and “TRV MODE ON” will be displayed.
3. Connect an oscilloscope to the TP513 (TE) and TP504 (AVC)
on the MAIN board.
4. Check that the level A and B of waveform on the oscillo-
scope satisfy the specification.
Specified Value:
Disc
A
B
SATD-S5 or
SATD-S4
PATD-012 or
0.9 to 1.4 Vp-p
–0.1 to +0.1V
YEDS-18
Checking and Connecting Location : See page 19.
MAIN board
TP513 (TE)
TP504 (AVC)
+
oscilloscope
A
B
VC
Center fo the waveform
Traverse waveform
l
L
SCD-XB780
19
19
– MAIN Board (Component Side) –
TP506
(FE)
TP513
(TE)
TP504
(AVC)
TP704
(AGND) TP703
(RFAC)
TP514
(RFCK)
TP517
(WFCK)
TP808 (DG)
IC703
IC701
IC509
IC801
CLV Jitter Check (CD only)
Connection:
Checking Method:
Under the condition of RF level check mode in step 3, connect the
oscilloscope to the TP516 (RFCK) (CH1), TP517 (WFCK) (CH2),
and the TP808 (DG) (GND) on the MAIN board to check that the
value A of the waveform satisfies the specification.
Note:
 Take care not to leave the test disc in the set.
Specified Value:
Disc
A
PATD-012 or
35 
µ
sec or less
YEDS-18
Checking and Connecting Location:
A
CLV jitter waveform
MAIN board
TP516 (RFCK)
TP517(WFCK)
TP808 (DG)
+
+
oscilloscope
(CH2)
(CH1)
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