NAD T 751 Bedienungsanleitung
NAD
SERVICE MANUAL
T 571
T 571
DVD / VCD / CD
PLAYER
DVD / VCD / CD
PLAYER
DRAFT DATE: 30 OCT, 2002
CONTENTS
SECTION 1 . . . .SUMMARY
SECTION 2 . . . .CABINET & MAIN CHASSIS
SECTION 3 . . . .ELECTRICAL
SECTION 4 . . . .MECHANISM
SECTION 5 . . . .REPLACEMENT PARTS LIST
SECTION 1
SUMMARY
CONTENTS
PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS
........................... 1-3
SERVICING PRECAUTIONS .................................................................................................. 1-4
• General Servicing Precautions
• Insulation Checking Prodedure
• Electrostatically Sensitive Devices
SPECIFICATIONS ...................................................................................................................... 1-5
1-3
Prior to shipment from the factory, the products are strictly inspected to conform with the recognized product
safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such com-
pliance, it is equally important to implement the following precautions when a set is being serviced.
•Precautions during Servicing
1. Locations requiring special caution are denoted by labels and inscriptions on the cabinet, chassis and
certain parts of the product. When performing service, be sure to read and comply with these and other
cautionary notices appearing in the operation and service manuals.
2. Parts identified by the symbol and shaded (
Y
) parts are critical for safety.
Replace only with specified part numbers.
Note : Parts in this category also include those specified to comply with X-ray emission standards for
products using cathode ray tubes and those specified for compliance with various regulations
regarding spurious radiation emission.
3. Use Specified internal wiring. Note especially:
1) Double insulated wires
2) High voltage leads
4. Use specified insulating materials for hazardous live parts. Note especially:
1) Insulation Tape
2) PVC tubing
3) Spacers
4) Insulation sheets for transistor
5. Observe that wires do not contact heat producing
parts (heatsinks, oxide metal film resistors, fusible
resistors, etc.)
6. Check that replaced wires do not contact sharp edged
or pointed parts.
7. 1) When a power cord has been replaced, check
that A mark is made on the cord, under strain,
near the aperture, and the flexible cord is
subjected 100 times to a pull of 40N for a duration
of 1 second each.
2) During the test, the cord shall not be displaced by
more than 2mm
8. Also check areas surrounding repaired locations.
IMPORTANT SAFETY PRECAUTIONS
Fig. 1
Power cord
1-4
Fig. 3
SAFETY CHECK AFTER SERVICING
Examine the area surrounding the repaired location for damage or deterioration. Observe that screws, parts and
wires have been returned to original positions. Afterwards, perform the following tests and confirm the specified
values in order to verify compliance with safety standards.
•Insulation resistance test
confirm the specified insulation resistance or greater between power cord plug prongs and externally exposed
parts of the set (RF terminals, antenna terminals, video and audio input and output terminals, microphone
jacks, earphone jacks, etc.) See table below.
•Dielectric strength test
Confirm specified dielectric strength or greater between power cord prongs and exposed accessible parts of
the set (RF terminals, antenna terminals, video and
audio input and output terminals, microphone jacks,
earphone jacks, etc.) See table below.
•Clearance distance
When replacing primary circuit components, confirm
specified clearance distance (d), (d') between sol-
dered terminals, and between terminals and sur-
rounding metallic parts. See table below.
Table 1 : Ratings for selected areas
* Class II model only.
Note. This table is unofficial and for reference only. Be sure to confirm the precise values for your particular
country and locality.
•Leakage Current test
Confirm specified or lower leakage current between B(earth ground, power cord plug prongs) and externally
exposed accessible parts (RF terminals, antenna terminals, video and audio input and output terminals, micro-
phone jacks, earphone jacks, etc.)
Measuring Method: (Power ON)
Insert load Z between B(earth ground, power cord
plug prongs) and exposed accessible parts. Use an
AC voltmeter to measure across both terminals of
load Z. See figure and following table.
Table 2:Leakage current ratings for selected areas.
Note. This table is for IEC member only. Be sure to confirm the precise values for your particular country and
Note. locality.
Chassis
d
a
Primary circuit terminals
Exposed
accessible
part Z
Load AC Voltmeter
Earth Ground,
Power cord plug prongs
B
Fig. 2
AC Line Voltage
AC Line Voltage
200 to 240 V
100 to 130 V
*200 to 240 V
*100 to 130 V
Europe
Australia
Europe
Australia
Other terminals
Antenna earth
terminals
i E0.7m A peak
i E2m A DC
i E0.7m A peak
i E2m A DC
F10 MΩ/500 V DC 4kV 1 minute F6mm(d)
F8mm(d)
(a Power cord)
Region Load Z Leakage Current(i) Earth Ground
(B) to :
Region Insulation
Resistance Dielectric
Strength Clearance
Distance(d),(d)
2kΩ
50kΩ
1-5
SPECIFICATIONS
DVD VIDEO PLAYER
Power supply AC 120 V, 60 Hz (T571AH)
AC 110~240 V, 50/60 Hz (T571C)
Power consumtion 16 W
Mass 5.7 kg(12.6 lbs)
External dimensions 440 x 118 x 423 mm (W x H x D)
Signal system NTSC (T571AH)
PAL (T571C)
Laser (DVD) Semiconductor laser, wavelength 650 nm
(CD) 780 nm
Frequency range (audio) DVD : fs = 96 kHz 4 Hz - 44 kHz
fs = 48 kHz 4 Hz - 22 kHz
CD: 4 Hz - 20 kHz
Signal-to-noise ratio (audio) More than 105dB (EIAJ)
Audio dynamic range (audio) More than 100dB (EIAJ)
Harmonic distortion(audio) 0.003%
Wow and flutter Below measurable level (less than +0.001%(W.PEAK)) (EIAJ)
Operations Temperature : 5˚C(41˚F) to 35˚C(95˚F),
Operation status : Horizontal
OUTPUTS
Video outputs 1.0V(p-p), 75Ω, negative sync., RCA jack x 1/
SCART(TO TV) (T571C ONLY)
S-video outputs (Y)1.0V(p-p), 75Ω, negative sync.,Mini DIN 4-pin x 1
(C)0.286V(p-p), 75Ω
Component video output (Y)1.0V(p-p), 75Ω,negative sync., RCA jack x 1
(Pb)/(Pr) 0.7V(p-p), 75Ω
Audio output(digital audio) 0.5V(p-p), 75Ω, RCA jack X 1/SCART(TO TV) (T571C ONLY)
Audio output(analog audio) 2.0Vrms (1kHz, 0dB), 330Ω, RCA jack (L, R) x 2/
SCART(TO TV) (T571C ONLY)
*Designs and specifications are subject to change without notice.
2-1
SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
1. DISASSEMBLY.........................................................................................................................2-2
CABINET DISASSEMBLY ............................................................................................................2-2
CIRCUIT BOARD DISASSEMBLY ...............................................................................................2-3
2. EXPLODED VIEWS ................................................................................................................2-4
1. Cabinet and Main Frame Section...........................................................................................2-4
2. Packing Accessory Section....................................................................................................2-5
2-2
DISASSEMBLY
CAUTION BEFORE STARTING SERVICING
Electronic parts are susceptible to static electricity and may easily and damaged, so do not forget to take a
proper grounding treatment as required.
Many screws are used inside the unit. To prevent missing, dropping, etc. of the screws, always use a
magnetized screw driver in servicing. Several kinds of screws are used and some of them need special
cautions. That is, take care of the tapping screws securing molded parts and fine pitch screws used to secure
metal parts. If they are used improperly, the screw holes will be easily damaged and the parts can not be fixed.
Top Case
(A)
(A) (A) (A)
(A)
(A)
(A)
Disc Tray
Tray Door
Front Panel Stopper
Stopper
CABINET DISASSEMBLY
1. Top Case
1. Release 7 screws (A). (See Fig. 2-1)
2. Lift the top case with holding the back of it,
and remove it in the direction of the arrow.
Fig. 2-1
Fig. 2-2
Fig. 2-3
3. Front Panel
1. Eject the disc tray. (See Fig. 2-2)
2. Remove the tray door. (See Fig. 2-2)
3. Pull the front panel toward you while pressing
5 stoppers to disengage, and remove the front
panel. (See Fig. 2-3)
2.Tray Door
1.Eject the disc tray.
2.Lift up the tray door in the direction of the
arrow.
2-3
(L1)
(L1)
(B)
(B)
(C) (C)
(C)
Power Code
Power
Circuit
Board
Main Chassis
MAAss'y Dpm1
Bracket Main
Jack Circuit Board
(F) (F)
(F)
(F)
Main Circuit Board
(B)
(B)
(D)
(E)
(D)
(D)
(D)
(E) (E)
(B)
(B)
(G)
(G)
(G) (G)
(G)
(G)
Fig. 2-4
Fig. 2-5
1. Disassemble Main circuit board, Jack
circuit board, Power circuit board and
MD Ass'y DPM1.
1. Remove the top case.(See Fig. 2-1)
2. Remove 10 screws (B).
3. Disassemble Main circuit board and Jack circuit
board from Bracket Main.
4. Unscrew 3 screws(C) at Bracket Main.
5. Disassemble Bracket Main from Main chassis.
6. Unscrew 4 screws(D) at MD Ass'y DPM1.
7. Turn the portion the direction of arrow to move
the Base Assembly Tray in front of you.
8. Release the other 3 screws(E).
9. Disassemble MDAss'y DPM1 from Main chassis.
10. Unscrew 4 screws(F) at Power circuit.
11. Disassemble power circuit board from Main
chassis.
CIRCUIT BOARD DISASSEMBLY
Note: Before removing the main circuit board, be sure to shortcircuit the laserdiode output land.
After replacing the main circuit board, open the land after inserting the flexible connector.
(Refer to Mechanism Disassembly)
2. Digitron and Key Circuit Board
1. Remove the front panel.(See Fig. 2-3)
2. Release 6 screws (G), and remove the digitron
circuit board.
2-4
EXPLODED VIEWS
1. Cabinet and Main Frame Section
465
465
250
462
462
300
465
260
465
A46
A47
463
463
275
463
463
463
467
A48
463
463
463
463
463
A00
A43
280
285
262
452
452
DIG901
PBTOO
283
A
5
4
3
2
1
BCD
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