Nad T 737 Service Manual

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SERVICE MANUAL

T737

nd Sound Receiver

T737

AV Surround Sound Receiver

AV Surrou

Page 2

SECTION 1

SUMMARY
CO NTE NTS
PRODUCT SAFETY SERVICING GUIDELINES .......................................................................................... 143
SERVICING PRECAUTIONS ....................................................................................................................... 1-4
* General Servicing Precautions
* Insulation checking prodedure
* Electrostatically Sensitive Devices
SPECIFICATIONS ......................................................................................................................................... 1-5
DISASSEMBLY .......... 1-6
PRINCIPAL PART LOCATION ...................................................................................................................... 1-7
EXPLODED VIEW ........................................................................................................................................ 1-8

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Page 26

Pln Functions

Pin No. Symbol Function Description
V55 Ground Ground connection _
2 Xtalml I 'll . Connection lor the crystal and capacitor used to form the crystal oscillator that generates
a xm'OUTl Crysta °5c' ator °°n"°c"° the internal synchronization signal. The oscillator can be selected with a command switch.
A HSYNC Horizontal synchronization Outputs the horizontal synchronization signal (AFC). The output polarity can be selected
OUT output (metal option). Also lunctions as general output port (command switch),
Xtalm , , Connection for the crystal and capacitor used to lorm the crystal oscillator that generates
X l Crystal C'llamr connection the internal synchronization signal.
'3 ourz
. _ _ Outputs the vertical synchronization signal. The output polarity can be selected (metal
7 VSYNCOUT Vertical synchronization output option). Also lunctions as general output port (command switch).
_ , Enables/disables serial data input. Serial data is enabled when this pin is low (hysteresis
a CS Enable input input), Pull-up resistor built in (metal option).
9 SW Data input Serial data input (hysteresis input). Pull»up resistor built in (metal option).
10 SCLK Clock input Clock input lor serial data input (hysteresis input). Pull-up resistor built in (metal option).
, , During input, swnches between SECAM and other modes.
11 SECAM SECAM mode szlwh, "ng During output, lunctions as general output port or internal V output (command switch).
output (oomman swuc ) Low = other modes, high = SECAM mode
, . During input, switches between 525 scan lines and 625 scan lines,
12 @1625 525/625 521? iaput/output During output. lunctions as general output port or character data output (command switch).
(oomman swrtc ) Low = 525 lines, high a 625 lines
. . Swrtches the color mode between NTSC and PAL.
13 NTSC/PAL NTSCPA: WI: input/output During output, lunctions as general output port or lrame data output (command switch).
l°°"a" W'm i Low e NTSC. high = PAL
Switch FSC between 3.58 MHz and 4.43 MHZ,
14 ass/4.43 ass/4.43 switch input/output During output. lunctions as general output port or halltone output (command switch).
(command switch) Low = 3.58, high = 4.43
- . System reset input pin, low is active (hysteresis input).
15 HST Reset input Pull-up resistor built in (metal option).
16 CVouT Video signal output Composite video output
17 VDDZ Power supply connection Power supply connection lor composite video signal level generation
18 CVIN Video signal input Composite video input
19 CVCFI Video signal input SECAM chroma signal input
20 SVNCm Sync separator circuit input Built-in sync separator circuit video signal input
21 SEPc Sync separator circuit Built-in sync separator circuit
22 V55 Ground Ground connection
23 PDOUT Control voltage output AFC control voltage output
p
24 AM IN AFC lilter connection Filter connection
25 AMPOUT
25 FC Control voltage input AFC control voltage input
7 . . ,
2 VCO'N LC oscillator connection VCO LC oscillator circuit coil and capacitor connection
26 VCOOUT
E -| h ization si nal Outputs the exclusive NOR ol the horizontal synchronization signal (AFC) and CSYNC (sync
29 SYNCDET dxlterrtansoynf ff" 9 separator). The output polarity can be selected (metal option). Also lunctions as general
e ec '0 u pu output port (command switch).
30 VDDi Power supply connection Power supply connection (+5 V: digital system power supply)

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SECTION 3

ELECTRICAL PARTS LIST

I RESISTORS AND CAPACITORS
Notes : * Please use this part number for parts order.
* IMPORTANT SAFETY NOTICE.

Components identified by A mark have special characteristics important for safety.
When replacing any of these components, use only manufacture's specified parts.

* The unit of resistance is ohm(SE)
k=1000§2 ,M=1000k§2
* The unit of capacitance is microfaradwF)

p=10-6 #F
I Numbering System of Resistor
example
E E E i u
Type Wattage Shape Tolerance Value
RESISTOR TYPE WATTAGE TOLERANCE
K(C)RD CARBON 10: 1/10 W F : :1 %
K(C)RJ CARBON CHIP 14: 1/4 W J : :10 %
K(C)RG METAL OXIDE 20: 1/5 W K : :20 %
K(C)RF METAL CEMENT 25: 1/4 W
K(C)RQ FUSIBLE 1 : 1 W
2 : 2 W
3 : 3 W
I Numbering System of Capacitor
example
% T m m L E
Type Voltage Value Tolerance Peculiarity
Capacitor Type VOLTAGE Tolerance
HCEA Type IOther
HCB CERAMIC OJ : 6.3V 1H :50V DC C : i0.25pF
CCC CERAMIC 1A :10V 1 :125V DC G : i2 %
CCK CERAMIC 1C : 16V KC : 400V AC J: :5 %
HCQ MYLAR 1E :25V K : :10 %
HCU CERAMIC CHIF 1H :50V 2 : +80%,-20%
HCE ELECT. 1V :35V

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