Nad 7400 Service Manual

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NAD SERVICE
MANUAL

MONITOR SERIES

7400

RECEIVER

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NAD 7400 SERVICE MANUAL
CONTENTS

Safety Notice

Rear/Front View
Specifications

Main Amp, Preamp Alignment

Tuner Alignment

WNIPPN

3. Schematics, Foil Diagrams
21. Wiring Diagram

23. Exploded View

24. Exploded View Parts List
27. Electrical Parts List

33. Remote Control Transmitter

Version Voltage Country

A 120 USA

A1 120 Canada

8 240 UK

Bi 240 Australia

C 220 Europe, others
Ci 220 W. Germany
6/3 220 Scandinavia

SERVICE SAFETY PRECAUTIONS (UL)

1. Use exactreplacernent parts for critical locations, marked A on parts list.
2. Return lead dress to original position, and re-install protective covers.
3. Before returning to customer, test for shock hazard; use either method A or B:
A. Leakage test, cold:
1. Unplug AC cord, turn power switch ON.
2. Connect one lead of High Voltage Insulation Tester to both prongs of AC plug.
3. Touch other lead to all exposed metal parts.
4. Impedance measurement must be 0.3 - 5.0 Megohms.\
B. Leakage test, live":
. Plug unit directly into AC outlet; do not use isolation transformer.
. Connect one lead of Leakage Current Tester to earth ground.
Touch other lead to all exposed metal parts.
. Leakage measurement must be less than 0.5 mil/lamps.

u

span

(hi

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4) LED DISPLAY ASSEMBLY; 00153 (EXPLODED VIEW INDEX No.65)

PARTS NO. SYMBOL NO. DESCRIPTION
TD6301AP |C425 IC, DISPLAY DECODE
SBX1483-51 IC426 IR RECEIVER
25C1815 0425, 427. TRANSISTOR
23C2500 0426 TRANSISTOR
25A1015 0428 TRANSISTOR
183176 D425, 426. DIODE

TLR208 D427 LED (RED)

TL0208 D428, 429. LED (ORANGE)
SL-5653-0I LED425 LED DISPLAY

5) TACTILE SWITCH ASSEMBLY; SOSEA (EXPLODED VIEW INDEX No.64)

PARTS N0. SYMBOL NO. DESCRIPTION
ZSC1815 0429-435. TRANSISTOR
TLOGZOS D430-437. LED (ORANGE/G REEN)
TLR208 D438 LED (RED)

TLG208 D439-441. LED (GREEN)

TL0208 D442, 443. LED (ORANGE)
81-2345 S425~438 TACTILE SWITCH

6) LED INDICATOR ASSEMBLY; M125A (EXPLODED VIEW INDEX No.58)

PARTS NO. SYMBOL NO. DESCRIPTION
TL0208 0901 LED (ORANGE)
TLG208 D902-906f LED (GREEN)

7) MAIN/CONTROL/SUPPLV PCB ASSEMBLY; JOZGA (EXPLODED VIEW INDEX No.55)

PARTS No. SYMBOL No. DESCRIPTION
L816428 Icoo1 IC, MOTOR DRIVE
NJM78M05FA Icooz Ic, REG 5v, 0.5A
,uPC1237H or HA IC003 Ic, PROTECT
NJM204300 IC701, 702. IC, DUAL AMP
NJMZOGBDD IC703, 704, 753, 754. IC, DUAL AMP
ILPD6360C IC705 IC, FET sw
ZSC3421 0001 TRANSISTOR
2801815 0002, 007, 010, 012-014, TRANSISTOR
703, 804, 810, 814, 854,
860, 864.
23A1358 0003 TRANSISTOR
28A1015 0004, 009, 01 1, 803, 809, TRANSISTOR
853, 859.
2SC2655 0005 TRANSISTOR
zsA1020 0006 TRANSISTOR
2531116 0008 TRANSISTOR
ZSC2240 0015, 021, 805, 808, 815, TRANSISTOR
855, 858, 865.
283985 0016, 022. TRANSISTOR
ZSA970 0018, 024, 806, 807, 816, TRANSISTOR
856, 857, 866.

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