Nad 5420 Service Manual

Page 1

NAD SERVICE
MANUAL

5420

5425

COMPACT
DISC PLAYERS

Page 2

SAFETY INFORMATION

CAUTION

CAUTION- INVISIBLE LASER RADIATION WHEN OPEN AND
lNTEFILDCKS DEFEATEDI AVOID EXPOSURE TO BEAM
vonsxcm! UNSICHTBARE LASERSTRAHLUNG mm AUS
WENN DECKEL GEOFFNET UND WENN
SICHERHEITSVERHIEGELUNG UBERBRUCKT IST
NIGHT DEM STRAHL AUSSETZEN!
VARNINGE omme LASERSTHALNING NAR DENNA DEL
An QPPNAp OCH SPARR AR URKOPPLAD.
STRALEN AR FARLIG. ,
ADVARSEL- USVNLIG LASERSTRALING on ABNING NAR
SiKKERHEDSAFBRVDERl-Z ER UDE AF FUNKTION
UNDGA UDSFETTELSE FOR SIRALING
ATTENTION- RAYONNEMENT LASER ET ELECTROMAGNETIOUE
DANGEREUX 5| ouvem AVEC L' ENCLENCHEMENT
DE SECURITE ANNULE

CLASS 1 LASER PRODUCT

The lightning flash with arrowhead, within an equilateral
triangle, is intended to alert the user oi the presence oi
uninsulated dangerous voltage" within the products enclo-
sure; that may be of sufficient magnitude to constitute a
risk 01 electric sho¢k to persons.

The exclamation point within an equilateral triangle is intended
to alert the user of the presence or important operating and
maintenance (servicing) instructions in the literature
accompanying the appliance.

OPERATION.

THIS DEVICE COMPLIES WITH PART 15 OF THE FCC RULES.
OPERATION IS SUBJECT TO THE FOLLOWING TWO CONDITIONS:
(1) THIS DEVICE MAY NOT CAUSE HARMFUL INTERFERENCE, AND
(2) THIS DEVICE MUST ACCEPTANY INTERFERENCE RECEIVED,
INCLUDING INTERFERENCE THAT MAY CAUSE UNDERSIRED

Page 4

PAGE CONTENTS
2 SAFETY INFORMATION pf
3 FRONT/REAR PANEL CONTROLS I
4 CONTENTS AND SPECIFICATIONS .
5-8 ALIGNMENT PROCEDURE E;
9-10 PICK-UP REPLACEMENT
11 WIRING DIAGRAM
12 ADJUSTMENT POINTS
13-14 CIRCUIT DIAGRAM
15 P.C.B. LAYOUT(PARTS SIDE)
16 REMOTE CONTROL CIRCUIT
17 MECHANISM EXPLODED VIEW
18 MECHANISM EXPLODED PARTS LIST
19-22 ELECTRICAL PARTS LIST
23 EXPLODED VIEW
24 PACKING DIAGRAM
25 SERVICE CONTACT INFORMATION

SPECIFICATIONS NAD 5420/5425 COMPACT DISC PLAYER

Disc capacity

Programming capabiIity
DigitaI-to-Anaiogue Convertion
DigitaI fiIter

Anangue fiIter
Frequency response 5 Hz-20 KHz -
De-Emohasis error
THD (at 0 dB,1 KHZ)
IntermoduIation distortion
(19 & 20 KHZ)
Dynamic range
Linearity
SignaI-to-noise ratio A weighted
de-emphasis off
I de-emphasis on
Channe1 Separation 1 KHz
10 KHZ
Wow and f1utter

Output impendance
Output IeveI at 0 dB
DigitaI error correction

PHYSICAL SPECIFICATION

Width*hight*depth
Net weight
Shipping weight

SingIe disc,120 or 80 mm

16 tracks

MASH, 18-bit resqution.

4 times over-sampIed,1inear
phase with 18-bit coefficients
5-poIe active

-O/~0.5 dB

0.0025%

(-100 dB

(2

98 dB
$0.5 dB; 0 to -90 dB

106 dB

110 dB

>100 dB

)80 dB

UnmeasureabIe

(quartz crystaI accuracy)
120 Ohms

2 Vrms

CIRC with doubIe error
correction in C1 and CZ

420*90*260 mm
4.1 Kg
4.9 Kg

Page 8

FOCUS/TRACKING GAIN ADJUSTMENT

NOTE:
absolutely necessary.

It is recommended that these adjustment are not carried out unless

A frequency response analyzer is necessary to carry out this adjustment
precisely. However this adjustment has a wide tolerance so that even if the
adjustment has not been performed exactly the player will still work with an

acceptable level of performance.

The focus and tracking gain determine not only the vertical and horizontal

tracking characteristics,

but also the amount of mechanical noise from the

optical blocks two axis device and its sensitivity to mechanical shock.
Correct adjustment will be at the point where all the above criteria are

satisfied.

* When the gain is too high, the mechanical noise is high.

*
skipping will be poor.

Time taken from stop to play is excessive, or
track skip time is excessive.
(normally approx. 2 sec)

Music does not start when play is pressed or
track selection is made but disc rotates.

Intermittent sound during play or counter
stops.

High mechanical noise frOm optical block
during play.

when the gain is too low,the susceptibility to mechanical shock and

l
i

we. *1"!

"(wt A: