Matsushita Electric SL-CT720GC User manual
AD0504045AE
PortableCD Player
SL-CT720GC
Colours
(A)...........Blue Type
(S)...........Silver Type
Please use thismanual together with the service manual for Model
No. SL-CT720GD/SG, Order No. AD0409064C0.
2005 Matsushita ElectricIndustrial Co., Ltd. All rights reserved.
Unauthorized copying and distribution isaviolation of law.
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1. Note
-Thissimplified service manual isprovided to indicate the
differences between the original model No. SL-CT720SG-S and the
subsequent model No. SL-CT720GC-A/S.
2. Replacement Parts List
Note:
-Important safetynotice:
Components identified bymark have special characteristics
important for safety.
Furthermore, special parts which have purposes of fire-retardant
(resistors), high-qualitysound (capacitors), low-noise (resistors),
etc. are used.
When replacing anyof components, be sure to use only
manufacture’sspecified parts showninthe parts list.
-The parenthesized indications inRemarks columns specifythe
colours.
(A): Blue Type
(S): Silver Type
-All parts are supplied bySPC.
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Ref.No. Change of Parts No. Part Name & Description Pcs
Remarks
SL-CT720SG-S SL-CT720GC-A/S
CABINETPARTS
6RYK1400-S RYK1400-A BOTTOM CABINET 1 (
A)
7 RYF0729-S RYF0729-A CD LID UNIT 1 (
A)
9 RYK1399-S RYK1399-1S MIDDLE CABINET 1 (
S)
18 RKK0155A-2H RKK0155A-1H BATTERY LID 1 (
S)
24 RGU2334-S RGU2334-2S BUTTON,OPEN 1 (
S)
AccessoryParts
A1 RFKFHFAZ09EM RFKFHFAZ01E1 RECHARGEABLE BATTERIES 2
A8 RQT7725-Z --------- OPERATING INSTRUCTIONS 1
DELETE
A8 --------- RQT7724-A OPERATING INSTRUCTIONS 1
ADDITION
ARABIC
A10 RQCA1146 --------- SHEET(FOR POWER PLUG ADAPTOR) 1
DELETE
F0504KH
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1. Accessories
-AC adaptor for SL-CT720GD
(RFEA438Q-S).............................................1pc.
-AC adaptor for SL-CT720SG
(RFEA444Z-S)..............................................1pc.
-Stereo earphones
(L0BAB0000190)...........................................1pc.
-Wired remote control
(N2QCBD000046).........................................1pc.
-External batterycase
(RFA2666-H)..................................................1pc.
-Soft case
(RFC0071A-C)...............................................1pc.
-Rechargeablebatteries (with case)
(RFKFHFAZ09EM).........................................2pcs.
-Power plug adaptor for SL-CT720SG only
(K2DA42E00001)............................................1pc.
2. Location of Controls
3. Precaution of Laser Diode
Caution:
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Thisproduct utilizes alaser diode with the unitturned on, invisible
laser radiation isemitted from the pick-up lens.
Wavelength: 780 nm
Maximum output radiation power from pick-up: 100 W/VDE
Laser radiation from the pick-up lens issafetylevel, but be sure the
followings:
1. Donot disassemblethe optical pick-up unit, since radiation from
exposed laser diode isdangerous.
2. Donot adjust the variableresistor on the pick-up unit. Itwas
alreadyadjusted.
3. Donot look at the focus lens using optical instruments.
4. Recommend not to look at pick-up lens for along time.
4. Handling Precautions for Traverse Deck
The laserdiode inthe traverse deck (optical pick-up) maybreak downdue topotential
difference causedbystatic electricityof clothes orhumanbody.
So, be careful of electrostatic breakdownduring repairof the traverse deck (optical pick-up).
4.1. Handling of traverse deck (optical pick-up)
1. Donot subject the optical pick-up to staticelectricityas itis
extremelysensitive to electrical shock.
2. To protect the laser diode against electrostaticbreakdown, be
sure that the short land of the flexibleboard (FFCboard) should
be short-circuitbysolder before pulling out the FFC. Then
inserting ashort pinor similar object into the tipof the flexible
board. / (Refer to Fig. 4-1. )
3. Take care not to applyexcessive stress to the flexibleboard (FFC
board).
4. Donot turn the variableresistor (laser power adjustment). Ithas
alreadybeen adjusted. (Refer to Fig. 4-1. )
Fig. 4-1.
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4.2. Caution when replacing traverse deck
The newtraverse deck short-circuits bythe short pin, the foil (B) and short lands toprotect the
laserdiode against electrostatic breakdown. Be sure toreplace tonewone following
procedures.
1. Remove the short pinfrom the FFC, and then connect itto the
connector.
2. Cut the foil (B). (Refer to Fig. 4-1. )(Take care not to make contact
with cutting point each other.)
3. Unsolder the short lands. (Refer to Fig. 4-1. )
4.3. Grounding for electrostaticbreakdownprevention
4.3.1. Human bodygrounding
Use the anti-static wrist straptodischarge the static electricityfromyourbody. (RefertoFig. 4-2.
)
Fig. 4-2.
4.3.2. Worktablegrounding
Put a conductive material (sheet) orsteel sheet on the area where the traverse deck (optical pick
-up) is placed, and ground the sheet. (Referto Fig. 4-3. )
Fig. 4-3.
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Caution:
The staticelectricityof your clothes will not be grounded through
the wrist strap.
So take care not to let your clothes touch the traverse deck (optical
pick-up).
5. Operation Checks and Component Replacement /
Procedures
-Thissection describes procedures for checking the operation of
the major printed circuitboards and replacing the main
components.
-For reassemblyafter operation checks or replacement, reverse the
respective procedures. Special reassemblyprocedures are
described onlywhen required.
5.1. Checking for the P.C.B.
5.1.1. Checking forthe P.C.B. (A side)
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-Follow the (Step 1) , (Step 2) of item 5.3.
5.5. Replacement for the spindlemotor
-Follow the (Step 1) -(Step 4) of item 5.1.1.
-Follow the (Step 1) , (Step 2) of item 5.3.
6. Display of Self-Diagnostic Function
This unit (SL-CT720) has self-diagnostic function. It maydisplaybelow-mentionedon the remote
control display.
-The substance of self-diagnosticdisplay.
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Remote control display
(Press PLAYand STOPbutton. After 15 seconds, itisdisplayed
for 2seconds.)
Incase of this display, it maybe causing forabnormallymovements of traverse deck, touching
failure of RESTdetect switchand coming off orcutting off the flexible P.C.B.. It is necessaryfor
confirmation orrepairand replacement eachparts.
7. Checking the Operation Problems on the Traverse
Deck (Optical Pick-up)
Make sure tofollowthe procedures belowtocheck the operation problems of the traverse deck
(optical pick-up) before replacing it.
Replace the traverse deck onlyafterthe problemis identified.
7.1. Check the operations described below on the traverse deck
after replacing
7.1.1. Checking skipsearch
1. Playan ordinarymusical program disc.
2. Press the skipbutton to check for normal skipsearch operation
(inboth the forward and reverse directions).
7.1.2. Checking manual search
1. Playan ordinarymusical program disc.
2. Press the manual search button to check for smooth manual
search operation at either low or high speed (inboth the forward
and reverse directions).
7.1.3. Checking playability
1. Playthe 0.7mm black dot and the 0.7mm wedge on the
playabilitytest disc (SZZP1054C)and verifythat no sound skipor
noise occurs.
2. Playthe middletracks of the uneven test disc (SZZP1056C)and
verifythat no sound skipor noise occurs.
8. Automatic Adjustment Results Display Function /
(Self-Check Function)
Onthe unit (SL-CT720), eachautomatic adjustment result are displayedon the remote control
display. This function is convenient tocheck oridentifywhichautomatic adjustment circuit is
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incorrect.
The followings are the contents of the automatic adjustment result displays (Self-Check
Function).
8.1. How to displayautomaticadjustment results
1. Load the test disc (SZZP1054C).
2. Press the (SKIP/SEARCH)and (SKIP/SEARCH)
buttons simultaneouslyand holdthem, and additionallypress the
(PLAY/PAUSE) button.
3. Press the (STOP/TURN OFF) button once.
4. Anautomaticadjustment resultisdisplayed on the remote control
display.
8.2. Displayof automaticadjustment results (Self-Check Function)
<Example>
Followthe belowsteps whenE1 is displayed.
(Cause: Focus balance (FBC) is set beyond the limit.)
-Check if
1. the waveform or voltage of the focus servo circuitiscorrect, and
2. the optical pick-up returns to the normal state byexchanging the
traverse deck.
Followthe belowsteps whenE4 is displayed.
(Cause: Focus gain(FGC) is set beyond the limit.)
-Check if
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1. the waveform or voltage of the focus servo circuitiscorrect,
2. the focus coil of the optical pick-up iscorrect (around 8ohms),
and
3. the optical pick-up returns to the normal state byexchanging the
traverse deck.
Followthe belowsteps whenEFis displayed.
(Cause: All adjustments (TGC, FGC, TBC, FBC) are set beyond the limit.)
-Check if
1. the optical pick-up returns to the normal state byexchanging the
traverse deck, and
2. the waveform or voltage of the servo ICsare correct.
Note:
It is not always necessarytoexchange the traverse deck whenanerrormessage is displayed.
Be sure tocheck if the circuit is defective ornot before exchanging the traverse deck.
Note:
If anyotherdisc thanthe test disc (SZZP1054C) is used, anerrormessage maybe displayed.
This is not a malfunction.
9. Type Illustration of ICs, Transistors and Diodes
10. Schematic Diagram Notes
-Thisschematicdiagram maybe modified at anytime with the
development of new technology.
Notes:
S201:
Laser ON/OFF switch inONposition / (Itturns ONwith disc holder
closed.)
S202:
Rest detector switch inOFF position / (Itturns ONwhen optical
pick-up comes to innermost periphery.)
S301:
Play/pause ( )switch
S302:
Volume control switch (VOL-)
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