Jvc XLM 409 TN Service Manual

Page 1

XL-MSOQTN
XL-M4OSBK
XL»M409TN

JVD
SERVICE MANUAL

XL-M309TN
XL-M408BK
0 XL-M409TN [333%

DIGITAL AUDIO

XL-M409TN/XL-M4OBBK

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Contents

Safety Precautions ....................... 1-2 Initial Operetion Mechanism ............ 1-37

Important for Laser Products ............. 1-3 Operation check by each swith .......... 1-40

Instruction Book ....................... 1-4 Flow of Functional Operation

Discription of Major LSIs ............... 1-24 Until TOC is Read ........ 1-41

Internal Block Diagrams of Other ICs 1-31 Troubleshooting ........................ 1-42

Internal Connection Block Diagrams .................... Insertion
for the FL Display Tube 1-32 Schematic Diagrams ................ Insertion

Disassembly Procedures ................. 1-33 Printed Circuit Board Insertion

. Adjustment Procedures ................. 1-35 Exploded View of Assemblies and
Maintenance of Laser Pickup ........... 1-36 Application Points for Grease . Insertion
Replacement of Laser Pickup ........... I-36 Parts list ..................... Insertion
No.20380

Dec.199 2

Page 2

XL-M 309TN
XL-M4083K
XL-M409TN

-$afety Precautions

1. The design of this product contains special hardware and many circuits and components

specially for safety purposes. For continued protection, no changes should be made to the
original design unless authorized in writing by the manufacturer. Replacement parts must
be identical to those used in the original circuits. Services should be performed by
qualified personnel only.

.Alterations of the design or circuitry of the product should not be made. Any design

alterations of the product should not be made. Any design alterations or additions will
void the manufacturer's warranty and will further relieve the manufacture of responsibility
for personal injury or property damage resulting therefrom.

.Many electrical and mechanical parts in the products have special safety-related

characteristics. These characteristics are often not evident from visual inspection nor can
the protection afforded by them necessarily be obtained by using replacement components
rated for higher voltage, wattage, etc. Replacement parts which have these special safety
characteristics are identified in the Parts List of Service Manual. Electrical components
having such features are identified by shading on the schematics and by (A) on the Parts
List in the Service Manual. The use of a substitute repalcement which does not have the
same safety characteristics as the recommended replacement parts shown in the Parts List of
Service Manual may create shock, fire, or other hazards.

.The leads in the products are routed and dressed with ties, clamps, tubings, barriers and

the like to be separated from live parts, high temperature parts, moving parts and/or sharp
edges for the prevention of electric shock and fire hazard. When service is required, the
original lead routing and dress should be observed, and it should be confirmed that they
have been returned to normal, after re-assembling.

. Leakage currnet check (Electrical shock hazard testing)

After re-assembling the product, always perform an isolation check on the exposed metal
parts of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack,
contorl shafts, etc.) to be sure the product is safe to operate without danger of electrical
shock.

Do not use a line isolation transformer during this check.

0 Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester,
measure the leakage current from each exposed metal parts of the cabinet, particularly
any exposed metal part having a return path to the chassis, to a known good earth
ground. Any leakage current must not exceed 0.5mA AC (r.m.s.).

0 Alternate check method
Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000
ohms per volt or more sensitivity in the following manner. Connect a 1,5000 10 W
resistor paralleled by a 0.15 ,uF AC-type capacitor between an exposed metal part and a
known good earth ground.

AC VOLTMETER

kw

Measure the AC voltage across the resistor 4
with the AC voltmeter. a Lia/wagon. . _
Move the resistor connection to each exposed o 0_ °' '°'9 senst'v'tfl
metal part, particularly any exposed metal part
having a return path to the chassis, and 0.15»: AC TYPE
meausre the AC voltage across the resistor. -||-
Now, reverse the plug in the AC outlet and 319*
repeat each measurement. Any voltage W >gg3h223md
measured must not exceed 0.75VAC (r.m.s.). 15°09 10 metal part
This corresponds to 0.5 mA AC (r.m.s.). Good earth ground

-Warning

. This equipment has been designed and manufactured to meet international safety standards.
. It is the legal responsibility of the repairer to ensure that these safety standards are

maintained.

. Repairs must be made in accordance with the relevant safety standards.
. It is essential that safety critical components are replaced by approved parts.
. lf mains voltage selector is provided, check setting for local voltage.

1-2 (No.20380)

Page 42

XL-M309TN

XL-M4OSBK
XL-M409TN
Troubleshooting
The following flowchart shows each Circuits condition about from power on until ready to play. .
V
Power on 5:th Qlroeisent YES
collector 7
NO NO
Does the FL
Does the FL Does not . - Check the
display light N0 entire FL NO ggglayllghtand YES powersupply
correctly? llght- YES immediately? Circuits
YES
i th lsbpanof |thegdisrrifiay h
s e a norma ri List e
mechanism 0 display ingorregct, or does YES Cheek 19 R95 Ched the F'-
intial height set the display not change cIrcmt. display-
correctly? when buttons are
pressed?
YES NO .
r ___________
I Tothe initial I
I Operation of I
. Mechanism I
I section. I
|. ___________ J
Can the first r-T-o-the- _____ I
tune be read NO I flowcharts for I
when a disc Is __,: theslider servo:
loaded with I and focus I
play button 7 : servo circuit : .
YES L_SSE".°_"-__-__.i
T"? ':F """" 1
Can the first ' flgwceharts for '
selection be NO : thetrackin I
played by -->: servo. fee l
pressmg the" I servo and I
play button, : spindle sengo :
YES IL CllCUlt SBCKIOn.J
Check general
operation
Do the control .
keys on the front NO :ftthfeogezgalt Ion YES
panel W°;k micro computer
"DB'V - normal?
YES NO
Defective
ICZOI
Arde display an:
in ieationo t e NO '
FL display dDigfe'active FL
normal? 9 y
YES
OK

1-42 (No.20380)