DOWNLOAD Sony DHC-MD777 / HMC-MD777 Service Manual ↓ Size: 7.32 MB | Pages: 108 in PDF or view online for FREE

Model
DHC-MD777 HMC-MD777
Pages
108
Size
7.32 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
dhc-md777-hmc-md777.pdf
Date

Sony DHC-MD777 / HMC-MD777 Service Manual ▷ View online

– 10 –
CHECKS PRIOR TO PARTS REPLACEMENT AND ADJUSTMENTS
Before performing repairs, perform the following checks to determine the faulty locations up to a certain extent.
Details of the procedures are described in “5 Electrical Adjustments”.
• 0.9 mW power
Specified value : 0.84 to 0.92 mW
• 7.0 mW power
Specified value : 6.8 to 7.2 mW
lop (at 7mW)
• Labeled on the optical pickup
Iop value ± 10mA
• Traverse waveform
Specified value : Below 10% offset
• Error rate check
Specified value : For points a, b, and c
C1 error : Below 220
AD error : Below 2
• Error rate check
Specified value:
a.
When using test disc (MDW-74/AU-1)
C1 error : Below 80
AD error : Below 2
b.
When using check disc (TDYS-1)
C1 error : Below 50
• CPLAY error rate check
Specified value:
C1 error : Below 80
AD error : Below 2
• If NG, displayed as “T=@@ (##) [NG]”
(@@, ## are both arbitrary numbers)
Laser power check
(See page 33)
Traverse check
(See page 33)
Focus bias check
(See page 34)
C PLAY check
(See page 34)
Self-recording/playback
check
(REC/PLAY)
(See page 34)
Temperature
compensation
offset check
(See page 35)
Criteria for Determination
(Unsatisfactory if specified value is not satisfied)
• Clean the optical pick-up
• Adjust again
• Replace the optical pick-up
• Replace the optical pick-up
• Replace the optical pick-up
• Replace the optical pick-up
• Replace the optical pick-up
If always unsatisfactory:
• Replace the overwrite head
• Check for disconnection of the circuits around the
overwrite head
If occasionally unsatisfactory:
• Check if the overwrite head is distorted
• Check the mechanism around the sled
• Check for disconnection of the circuits around
D101 (BD (MD) board)
• Check the signals around IC101, IC121, CN102,
CN103 (BD (MD) board)
Measure if unsatisfactory:
Note:
The criteria for determination above is intended merely to determine if satisfactory or not, and does not serve as the specified value for adjustments.
When performing adjustments, use the specified values for adjustments.
– 11 –
1
1kHz/0dB/L&R
22
1kHz/-90dB/L&R
2
20Hz/0dB/L&R
23
Infinity Zero w/o emphasis//L&R
3
40Hz/0dB/L&R
24
Infinity Zero with emphasis//L&R
4
100Hz/0dB/L&R
25
400Hz+7kHz(4:1)/0dB/L&R
5
200Hz/0dB/L&R
26
400Hz+7kHz(4:1)/-10dB/L&R
6
500Hz/0dB/L&R
27
19kHz+20kHz(1:1)/0dB/L&R
7
1kHz/0dB/L&R
28
19kHz+20kHz(1:1)/-10dB/L&R
8
5kHz/0dB/L&R
29
100Hz/0dB/L*
9
7kHz/0dB/L&R
30
1kHz/0dB/L*
10
10kHz/0dB/L&R
31
10kHz/0dB/L*
11
16kHz/0dB/L&R
32
20kHz/0dB/L*
12
18kHz/0dB/L&R
33
100Hz/0dB/R*
13
20kHz/0dB/L&R
34
1kHz/0dB/R*
14
1kHz/0dB/L&R
35
10kHz/0dB/R*
15
1kHz/-1dB/L&R
36
20kHz/0dB/R*
16
1kHz/-3dB/L&R
37
100Hz  Squer Wave//L&R
17
1kHz/-6dB/L&R
38
1kHz  Squer Wave//L&R
18
1kHz/-10dB/L&R
39
1kHz  w/emphasis/-0.37dB/L&R
19
1kHz/-20dB/L&R
40
5kHz  w/emphasis/-4.53dB/L&R
20
1kHz/-60dB/L&R
41
16kHz  w/emphasis/-9.04dB/L&R
21
1kHz/-80dB/L&R
TRACK
No.
Displayed Contents
Note: 
The contents of Track No. 1 to 41 are the same as those of the current TEST DISC-their titles are displayed.
TRACK
No.
Displayed Contents
CD  SECTION
CD-TEXT TEST  DISC
This unit is able to display the test data (character information) written in the CD on its fluorescent indicator tube.
The CD-TEXT TEST DISC (TGCS-313: 4-989-366-01) is used for checking the display.
To check, perform the following procedure.
Checking Method:
1. Turn ON the power, set the disc to the disc tray with the “test disc” label facing up, and chuck the disc.
2. Press the
· button and play back the disc.
3. The following will be displayed on the fluorescent indicator tube.
Display: 1kHz/0 dB/ L&R
4. Turn the
± dial or press the ≠ / ± (CD) button on remote commander and select the track. The text data of each
track will be displayed.
For details of the displayed contents for each track, refer to “Table 1: CD-TEXT TEST DISC TEXT Data Contents” and “Table 2: CD-
TEXT TEST DISC Recorded Contents and Display”.
Restrictions in CD-TEXT Display
In this unit, some special characters will not be displayed properly. These will be displayed as a space or a character resembling it. For
details, refer to “Table 2: CD-TEXT DISC Recorded Contents and Display”.
Table 1: CD-TEXT TEST DISC TEXT Data Contents (TRACKS No. 1 to 41: Normal Characters)
– 12 –
Table 2: CD-TEXT TEST DISC Recorded Contents and Display
(In this unit, some special characters cannot be displayed. This is no a fault.)
TRACK
No.
Recorded contents
´
*
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
to
99
! ” # $ % & ´
(21h to 27h)1kHz 0dB L&R
(  )
+ , – . /
(28h to 2Fh)
0 1 2 3 4 5 6 7
(30h to 37h)
8 9 : ; < = > ?
(38h to 3Fh)
@A B C D E F G
(40h to 47h)
H I J K L M N O
(48h to 4Fh)
P Q R S T U V W
(50h to 57h)
X Y Z [ ¥ ] ^ _
(58h to 5Fh)
a b c d e f g
(60h to 67h)
h i j k l m n o
(68h to 6Fh)
p q r s t u v w
(70h to 77h)
x y z { I }
(78h to 7Fh)
i ¢ £ ¤ ¥
§
(A0h to A7h) 8859-1
C
ª
¬
PR
(A8h to AFh)
±
2
3
µ
¶ •
(B0h to B7h)
1
º
¿
(B8h to BFh)
À Á Â Ã Ä Å ÆÇ
(C0h to C7h)
Ƞɠʠˠ̠͠ΠÏ
(C8h to CFh)
D Ñ Ò Ó Ô Õ Ö
(D0h to D7h)
ؠ٠ڠ۠ܠY
ß
(D8h to DFh)
à á â ã ä å æ ç
(E0h to E7h)
è é ê ë ì í î ï
(E8h to FFh)
ñ ò ó ô õ ö
÷
(F0h to F7h)
ø ù ú û ü y
ÿ
(F8h to FFh)
No.66
No.67
  to
No.99
˙
~
1
4
1
2
3
4
Display
N All the same
N All the same
N All the same
N All the same
N All the same
N All the same
N All the same
X Y Z [
] ^ _
(58h to 5Fh)
N All the same
N All the same
N All the same
N All the same
(A0h to A7h) 8859-1
        
  (A8h to AFh)
(B0h to B7h)
(B8h to BFh)
A A A A A A
C
(C0h to C7h)
E E E E I I I I
(C8h to CFh)
D N O O O O O
(D0h to D7h)
O U U U U Y
(D8h to DFh)
a a a a a a
c
(E0h to E7h)
e e e e i i i i
(E8h to EFh)
d n o o o o o
(F0h to F7h)
o u u  u u y
y
(F8h to FFh)
N All the same
N All the same
to
N All the same
/
– 13 –
SECTION  2
GENERAL
LOCATION  OF  CONTROLS
– Front Panel –
• CD PLAYER Section
• MD DECK Section
1 1/ALL button
2 PLAY MODE button
3 REPEAT button
4 fl button
5 π button
6 0 button
7 ) button
8 NAME EDIT button
9 MENU/NO button
!º ENTER/YES button
!¡ DISPLAY button
!™ CLEAR button
!£ ≠ ˜ ± dial
!¢ CD disc tray
!∞ CD1 button and indicator
!§ CD2 button and indicator
!¶ CD3 button and indicator
!• CD4 button and indicator
!ª CD5 button and indicator
@º DISC SKIP button
1 1/ALL button
2 PLAY MODE button
3 REPEAT button
4 fl button
5 π button
6 0 button
7 ) button
8 NAME EDIT button
9 MENU/NO button
!º ENTER/YES button
!¡ DISC SKIP button
!™ DISPLAY button
!£ CLEAR button
!¢ ≠ ˜ ± dial
!∞ OPEN button
!§ REC button
!¶ REC MODE button
!• MD WALKMAN SYNC button and indicator
!ª MD WALKMAN LINK jack
@º MD1 button and indicator
@¡ MD2 button and indicator
@™ MD3 button and indicator
@£ MD4 button and indicator
@¢ MD5 button and indicator
@∞ § button
3
2
1
4 5 6 7
8
9


!™
!¢ !∞ !§ !¶ !• !ª @º
3
2
1
4 5 6 7 8
@º @¡ @™ @£ @¢
9

!™

!∞
@∞


!•
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