Sony MDS-JB920 Service Manual ▷ View online
– 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-
• 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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
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
VC
TEO
MDM-3
MDM-5
IOP
I-3V
I-3V
VC
RF
TEO
IOP
I+3V
GND
RF
TEO
IOP
I+3V
GND
VC
RF
TEO
IOP
I+3V
GND
1
5
1
6
– 7 –
IOP Data Recording and Display When Pickup and Non-volatile Memory (IC171 of BD board) are Replaced
The IOP value labeled on the pick-up can be recorded in the non-volatile memory. By recording the value, it will eliminate the need to look
at the value on the label of the optical pick-up. When replacing the pick-up or non-volatile memory (IC171 of BD board), record the IOP
value on the pick-up according to the following procedure.
at the value on the label of the optical pick-up. When replacing the pick-up or non-volatile memory (IC171 of BD board), record the IOP
value on the pick-up according to the following procedure.
Record Precedure:
1. While pressing the
1. While pressing the
[ AMS ]
knob and p button, connect the power plug to the outlet, and release the
[ AMS ]
knob
and p button.
2. Rotate the
[ AMS ]
knob to display “[Service]”, and press the
[YES]
button.
3. Rotate the
[ AMS ]
knob to display “lop.Write” (C28), and press the
[YES]
button.
4. The display becomes “Ref=@@@.@” (@ is an arbitrary number) and the numbers which can be changed will blink.
5. Input the IOP value written on the optical pick-up.
5. Input the IOP value written on the optical pick-up.
To select the number : Rotate the
[ AMS ]
knob.
To select the digit
: Press the
[ AMS ]
knob.
6. When the
[YES]
button is pressed, the display becomes “Measu=@@@.@” (@ is an arbitrary number).
7. As the adjustment results are recorded for the 6 value. Leave it as it is and press the
[YES]
button.
8. “Complete!” will be displayed momentarily. The value will be recorded in the non-volatile memory and the display will become “Iop
Write”.
9. Press the
[REPEAT]
button to complete. “Standby” will be displayed.
Display Precedure:
1. While pressing the
1. While pressing the
[ AMS ]
knob and p button, connect the power plug to the outlet, and release the
[ AMS ]
knob
and p button.
2. Rotate the
[ AMS ]
knob to display “[Service]”, and press the
[YES]
button.
3. Rotate the
[ AMS ]
knob to display “lop.Read” (C27).
4. “@@.@/##.#” is displayed and the recorded contents are displayed.
@@.@ : indicates the Iop value labeled on the pick-up.
##.#
##.#
: indicates the Iop value after adjustment
5. To end, press the
[ AMS ]
button or
[MENU/NO]
button to display “Iop Read”. Then press the
[REPEAT]
button to display
“Standby”.
[ ]
[ ]
±
≠
±
≠
±
≠
±
≠
±
≠
±
≠
±
≠
±
≠
±
≠
±
≠
[ ]
±
≠
[ ]
– 8 –
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”.
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
C1 error : Below 220
AD error : Below 2
• Error rate check
Specified value:
a.
a.
When using test disc (MDW-74/AU-1)
C1 error : Below 80
AD error : Below 2
C1 error : Below 80
AD error : Below 2
b.
When using check disc (TDYS-1)
C1 error : Below 50
C1 error : Below 50
• CPLAY error rate check
Specified value:
C1 error : Below 80
AD error : Below 2
C1 error : Below 80
AD error : Below 2
• Unsatisfactory if displayed as T=@@ (##) [NG”
NG
(@@, ## are both arbitrary numbers)
(@@, ## are both arbitrary numbers)
Laser power check
(5-6-2 : See page 25)
(5-6-2 : See page 25)
Traverse check
(5-6-3 : See page 25)
(5-6-3 : See page 25)
Focus bias check
(5-6-4 : See page 26)
(5-6-4 : See page 26)
C PLAY check
(5-6-5 : See page 26)
(5-6-5 : See page 26)
Self-recording/playback
check
(REC/PLAY)
(5-6-6 : See page 26)
check
(REC/PLAY)
(5-6-6 : See page 26)
TEMP check
(Temperature
compensation
offset check)
(5-6-1 : See page 25)
(Temperature
compensation
offset check)
(5-6-1 : See page 25)
Criteria for Determination
(Unsatisfactory if specified value is not satisfied)
(Unsatisfactory if specified value is not satisfied)
• Clean the optical pick-up
• Adjust again
• Replace 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
• 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 if the overwrite head is distorted
• Check the mechanism around the sled
• Check for disconnection of the circuits around
D101 (BD board)
• Check the signals around IC101, IC121, CN102,
CN103 (BD 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.
When performing adjustments, use the specified values for adjustments.
Forced Reset
The system microprocessor can be reset in the following procedure.
Use these procedure when the unit cannot be operated normally due to the overrunning of the microprocessor, etc.
Procedure :
Disconnect the power plug, short-circuit jumper wire of JW705 and JW706 (RESET).
Use these procedure when the unit cannot be operated normally due to the overrunning of the microprocessor, etc.
Procedure :
Disconnect the power plug, short-circuit jumper wire of JW705 and JW706 (RESET).
[BAT BOARD] (Component Side)
JW706 JW705
CN703
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