DOWNLOAD Sony MDS-JB920 Service Manual ↓ Size: 5.05 MB | Pages: 72 in PDF or view online for FREE

Model
MDS-JB920
Pages
72
Size
5.05 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
mds-jb920.pdf
Date

Sony MDS-JB920 Service Manual ▷ View online

– 3 –
Items of Error History Mode Items and Contents
Selecting the Test Mode
Display
Details of History
E00
No error
E01
Disc error. PTOC cannot be read
(DISC ejected)
E02
Disc error. UTOC error
(DISC not ejected)
E03
Loading error
E04
Address cannot be read (Servo has deviated)
Table of Error Codes
Error Code
Error Code
Details of Error
total rec
Displays the recording time.
Displayed as “rππππππh”.
The displayed time is the total time the laser is set to the high power state.
This is about 1/4 of the actual recording time.
The time is displayed in decimal digits from 0h to 65535h.
total play
Displays the play time.
Displayed as “pππππππh”. The time displayed is the total actual play time. Pauses are not counted.
The time is displayed in decimal digits from 0h to 65535h.
retry err
Displays the total number of retries during recording and number of retry errors during play.
Displayed as “rππ pππ”.
“r” indicates the retries during recording while “p” indicates the retry errors during play.
The number of retries and retry errors are displayed in hexadecimal digits from 00 to FF.
total err
Displays the total number of errors.
Displayed as “total ππ”.
The number of errors is displayed in hexadecimal digits from 00 to FF.
err history
Displays the 10 latest errors.
Displayed as “0π E@@”.
π indicates the history number. The smaller the number, the more recent is the error. (00 is the latest).
@@ indicates the error code.
Refer to the following table for the details. The error history can be switched by rotating the 
[        AMS        ]
knob.
er refresh
Mode which erases the “retry err”, “total err”, and “err history” histories.
When returning the unit to the customer after completing repairs, perform this to erase the past error history.
After pressing the 
[        AMS        ]
 button and “er refresh?” is displayed, press the 
[YES]
 button to erase the
history.
“Complete!” will be displayed momentarily.
Be sure to check the following when this mode has been executed.
• The data has been erased.
• The mechanism operates normally when recording and play are performed.
tm refresh
Mode which erases the “total rec” and “total play” histories.
These histories serve as approximate indications of when to replace the optical pickup.
If the optical pickup has been replaced, perform this operation and erase the history.
After pressing the 
[        AMS        ]
 button and “tm refresh?” is displayed, press the 
[YES]
 button to erase the
history.
“Complete!” will be displayed momentarily.
Be sure to check the following when this mode has been executed.
• The data has been erased.
• The mechanism operates normally when recording and play are performed.
±
±
±
E05
FOK has deviated
E06
Cannot focus (Servo has deviated)
E07
Recording retry
E08
Recording retry error
E09
Playback retry error
(Access error)
E0A
Playback retry error (C2 error)
Details of Error
– 4 –
SECTION  1
SERVICING  NOTES
SAFETY  CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs,
screws, and all other exposed metal parts for AC leakage.
Check leakage as described below.
LEAKAGE  TEST
The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microampers.).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instruments.
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a
VOM or battery-operated AC voltmeter. The “limit” indica-
tion is 0.75 V, so analog meters must have an accurate low-
voltage scale. The Simpson 250 and Sanwa SH-63Trd are ex-
amples of a passive VOM that is suitable. Nearly all battery
operated digital multimeters that have a 2 V AC range are suit-
able.  (See Fig. A)
Fig. A.
Using an AC voltmeter to check AC leakage.
1.5 k
0.15 
µ
F
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
MODEL IDENTIFICATION
— BACK PANEL —
Part No.
4-998-603-1 
π
AEP and UK models
4-998-603-3 
π
US model
4-998-603-4 
π
Canadian model
TABLE  OF  CONTENTS
1.
SERVICING  NOTES
...............................................
4
2.
GENERAL
................................................................... 11
3.
DISASSEMBLY
......................................................... 14
4.
TEST  MODE
.............................................................. 18
5.
ELECTRICAL  ADJUSTMENTS
......................... 23
6.
DIAGRAMS
6-1. IC Pin Function Description ........................................... 32
6-2. Block Diagram – SERVO Section – ............................... 41
6-3. Block Diagram – MAIN Section – ................................. 43
6-4. Note for Printed Wiring Boards and
Schematic Diagrams ....................................................... 46
6-5. Printed Wiring Board  – BD Section – ........................... 47
6-6. Schematic Diagram – BD Section (1/2) – ...................... 49
6-7. Schematic Diagram – BD Section (2/2)– ....................... 51
6-8. Schematic Diagram – MAIN Section (1/3)– .................. 55
6-9. Schematic Diagram – MAIN Section (2/3)– .................. 57
6-10. Schematic Diagram – MAIN Section (3/3)– .................. 59
6-11. Printed Wiring Board
– MAIN Board (Side A) .................................................. 61
6-12. Printed Wiring Boards
– MAIN Board (Side B), AC/BAT Boards ..................... 63
6-13. Printed Wiring Boards
– PANEL Section – ......................................................... 65
6-14. Schematic Diagram  – PANEL Section – ....................... 67
6-15. Schematic Diagram
– BD SWITCH Section – ................................................ 69
6-16. Printed Wiring Board
– BD SWITCH Section – ................................................ 69
7.
EXPLODED  VIEWS
................................................ 75
8.
ELECTRICAL  PARTS  LIST
............................... 79
– 5 –
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270 ˚C dur-
ing repairing.
• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
• Be careful not to apply force on the conductor when soldering
or unsoldering.
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
ADVARSEL
Eksplosjonsfare ved feilaktig skifte av batteri.
Benytt samme batteritype eller en tilsvarende type
anbefalt av apparatfabrikanten.
Brukte batterier kasseres i henhold til fabrikantens
instruksjoner.
VARNING
Explosionsfara vid felaktigt batteribyte.
Använd samma batterityp eller en likvärdig typ som
 rekommenderas av apparattillverkaren.
Kassera använt batteri enligt gällande föreskrifter.
VAROITUS
Paristo voi räjähtää, jos se on virheellisesti asennettu.
Vaihda paristo ainoastaan laitevalmistajan suosittelemaan tyyppiin.
Hävitä käytetty paristo valmistajan ohjeiden mukaisesti.
ADVARSEL!
Lithiumbatteri-Eksplosionsfare ved fejlagtig håndtering.
Udskiftning må kun ske med batteri
af samme fabrikat og type.
Levér det brugte batteri tilbage til leverandøren.
CAUTION
Danger of explosion if battery is incorrectly replaced.
Replace only with the same or equivalent type recommended by
the manufacturer.
Discard used batteries according to the manufacturer’s instruc-
tions.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
Laser component in this product is capable of emitting radia-
tion exceeding the limit for Class 1.
This appliance is classified as
a CLASS 1 LASER product.
The CLASS 1 LASER PROD-
UCT MARKING is located on
the rear exterior.
This caution
label is located
inside the unit.
ATTENTION  AU  COMPOSANT  AYANT  RAPPORT
À  LA  SÉCURITÉ!
LES  COMPOSANTS  IDENTIFIÉS  PAR  UNE  MARQUE  
!
SUR  LES  DIAGRAMMES  SCHÉMATIQUES  ET  LA  LISTE
DES  PIÈCES  SONT  CRITIQUES  POUR  LA  SÉCURITÉ
DE  FONCTIONNEMENT.  NE  REMPLACER  CES  COM-
POSANTS  QUE  PAR  DES  PIÈCES  SONY  DONT  LES
NUMÉROS  SONT  DONNÉS  DANS  CE  MANUEL  OU
DANS  LES  SUPPLÉMENTS  PUBLIÉS  PAR  SONY.
SAFETY-RELATED  COMPONENT  WARNING!!
COMPONENTS  IDENTIFIED  BY  MARK  
!
  OR  DOTTED
LINE  WITH  MARK  
!
  ON  THE  SCHEMATIC  DIAGRAMS
AND  IN  THE  PARTS  LIST  ARE  CRITICAL  TO  SAFE
OPERATION.  REPLACE  THESE  COMPONENTS  WITH
SONY  PARTS  WHOSE  PART  NUMBERS  APPEAR  AS
SHOWN  IN  THIS  MANUAL  OR  IN  SUPPLEMENTS  PUB-
LISHED  BY  SONY.
– 6 –
JIG FOR CHECKING BD BOARD WAVEFORM
The special jig (J-2501-149-A) is useful for checking the waveform of the BD board. The names of terminals and the checking items to be
performed are shown as follows.
GND : Ground
I+3V : For measuring IOP (Check the deterioration of the optical pick-up laser)
IOP : For measuring IOP (Check the deterioration of the optical pick-up laser)
TE
: TRK error signal (Traverse adjustment)
VC
: Reference level for checking the signal
RF
: RF signal (Check jitter)
CN110
RF
5P Connector
6P connector
VC
TEO
IOP
I+3V
GND
Mechanism deck
RF
VC
TEO
MDM-3
MDM-5
IOP
I-3V
VC
RF
TEO
IOP
I+3V
GND
VC
RF
TEO
IOP
I+3V
GND
1
5
1
6
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Sony MDS-JB920 Service Manual ▷ Download

  • DOWNLOAD Sony MDS-JB920 Service Manual ↓ Size: 5.05 MB | Pages: 72 in PDF or view online for FREE
  • Here you can View online or download the Service Manual for the Sony MDS-JB920 in PDF for free, which will help you to disassemble, recover, fix and repair Sony MDS-JB920 Audio. Information contained in Sony MDS-JB920 Service Manual (repair manual) includes:
  • Disassembly, troubleshooting, maintenance, adjustment, installation and setup instructions.
  • Schematics, Circuit, Wiring and Block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Exploded View and Parts List.