NAD 5420 User manual

SERVICE
NAD
[MANUAL
9420
9429
‘
reve)
Vea
,
DISC
PLAYERS
~

SAFETY INFORMATION
CAUTION
CAUTION- INVISIBLE LASER RADIATION WHEN OPEN AND
INTERLOCKS DEFEATED. AVOID EXPOSURE TO BEAM.
VORSICHT! UNSICHTBARE LASERSTRAHLUNG TRITT AUS.
WENN DECKEL GEOFFNET UND WENN
SICHERHEITSVERRIEGELUNG UBERBRUCKT IST.
NICHT DEM STRAHL AUSSETZEN!
VARNING- OSYNLIG LASERSTRALNING NAR DENNA DEL
AR OPPNAD OCH SPARR AR URKOPPLAD.
STRALEN AR FARLIG. .
ADVARSEL- USYNLIG LASERSTRALING VED ABNING. NAR
SIKKERHEDSAFBRYDERE ER UDE AF FUNKTION.
UNOGA UDSAETTELSE FOR STRALING.
ATTENTION- RAYONNEMENT LASER ET ELECTROMAGNETIQUE
DANGEREUX SI OUVERT AVEC LU’ ENCLENCHEMENT
DE SECURITE ANNULE.
CLASS 1 LASER PRODUCT
The lightning flash with arrowhead, within an equilateral The exclamation point within an equilateral triangle is intended
triangle, is intended to alert the user of the presence of to alert the user of the presence of important operating and
uninsulated “dangerous voltage” within the product's encio- maintenance (servicing) instructions in the literature
sure; that may be of sufficient magnitude to constitute a accompanying the appliance.
risk of electric shock to persons.
| -
- THIS DEVICE COMPLIES WITH PART 15 OF THE FCC RULES.
j OPERATION !S SUBJECT TO THE FOLLOWING TWO CONDITIONS:
ats (1) THIS DEVICE MAY NOT CAUSE HARMFUL INTERFERENCE, AND
4 (2) THIS DEVICE MUST ACCEPT,ANY INTERFERENCE RECEIVED,
INCLUDING INTERFERENCE THAT MAY CAUSE UNDERSIRED
OPERATION.

. . Ba
. aes |
hn
REAR
PANEL
CONNECTIONS
i
AEA
mama
AISQUE DE CHOC TENTIO : PAS OUVAIA 1 OERERA QUTANSE ry
CAPACITAOO PARA LAS
LINE OUT
1. OUTPUT JACKS 2. AC LINE CORD
FRONT
PANEL
10
(5425
ONLY)
9
Compact
Disc
Player
5425
SKIP
SCAN
a
ha
|
]o
ese
eam
<<
(0
im)
>
in)
an
CLOSE
PLAY
PAUSE
iT
PROGRAM
REPEAT
OO
Oo
=
=
1
2
3
4 5 6
7
8
1.
POWER
ON/OFF
2.
DISC
DRAWER
3.
OPEN/CLOSE
4,
PLAY/PAUSE
5.
STOP
6.
PROGRAM/DISPLAY
7.
REPEAT
8.
SKIP/SCAN
9,
DISPLAY
10. REMOTE RECEIVER (5425 ONLY)
© 1990. NAD Electronics Ltd.
© 1990. NAD Electronics Ltd.

CONTENTS
SAFETY INFORMATION anal
FRONT/REAR PANEL CONTROLS 7
CONTENTS AND SPECIFICATIONS
ALIGNMENT PROCEDURE
PICK-UP REPLACEMENT
WIRING DIAGRAM
ADJUSTMENT POINTS
CIRCUIT DIAGRAM
P.C.B. LAYOUT(PARTS SIDE)
REMOTE CONTROL CIRCUIT
MECHANISM EXPLODED VIEW
MECHANISM EXPLODED PARTS LIST
ELECTRICAL PARTS LIST
EXPLODED VIEW
PACKING DIAGRAM
SERVICE CONTACT INFORMATION
SPECIFICATIONS NAD 5420/5425 COMPACT DISC PLAYER
Disc capacity
Programming capability
Digital-to-Analogue Convertion
Digital filter
Analogue filter
Frequency response 5 Hz-20 KHz
De-Emphasis error
THD (at O dB,1 KHz)
Intermodulation distortion
(19 & 20 KHz)
Dynamic range
Linearity
Signal-to-noise ratio A weighted
de-emphasis off
. de-emphasis on
Channel Separation 1 KHz
10 KHz
Wow and flutter
Output iImpendance
Output level at O dB
Digital error correction
PHYSICAL SPECIFICATION
Width*hightxdepth
Net weight
Shipping weight
Single disc,120 or 80 mm
16 tracks
MASH, 18-bit resolution.
4 times over-sampled, linear
phase with 18-bit coefficients
5-pole active
~0/-0.5 dB
<+0.3 dB
0.0025%
<~100 dB
98 dB
+0.5 dB; 0 to -90 dB
106 dB
110 dB
>100 dB
»80 dB
Unmeasureable
(quartz crystal accuracy)
120 Ohms
2 Vrms
CIRC with double error
correction in Ci and C2
420*90*260 mm
4.1 Kg
4.9 Kg

er
Fey.
aa
ALIGNMENT PROCEDURE
REQUIRED
INSTRUMENTS:
SPECIAL
JIG
(SEE
FIG.1)
OSCILLOSCOPE
(BANDWIDTH
GREATER
THAN
40
MHz)
FREQUENCY
COUNTER
TEST
DISK
(SONY
YEDS-7)
NOTE
Exact adjustment can only be performed with
special factory jigs etc. However the following
alignment procedure should produce a wel] aligned
player assuming no fault conditions are present.
It is suggested that the position of the preset
resistors setting is noted or marked before any
adjustment is attempted so that these settings
can be returned to, should no improvement be noted
after adjustment.
Please
refer
to
page
12
for
the
physical
location
of
the
adjustment
and
test
points.
Step A:
)
)
)
)
) NNN NN
oR OM —
Step B:
~~ oN
nN —
(3)
Step C:
(1)
(2)
PLL Adjustment
Turn power ON and press the STOP key.
Short circuit P108 (ASSY) to P107 (GND)
Connect the frequency counter to P106 (CLK) and P107 (GND)
Adjust RV101 for a reading of 4.2318+ 0.01MHz.
After adjustment is completed remove the short circuit between P108
and P1i07.
RF Adjustment
Load the test disc and set the unit into PLAY mode.
Connect the scope to P109 (RF) and P107 (GND).
Scope setting: Coupling : AC
Vertical sensitivity: 0.2V/div
Horizontal time base: 0.5uS/div
Adjust RV102 so that the 3T component of the waveform is maximun
and the eye pattern is at its best shape (see Fig 2)
EF Balance adjustment
Turn the power OFF, remove P1i11 and replace it with the special jig
shown in Fig 1.
Connect the scope as shown Fig 1. and switch the jig to the “ON”
position.
scope setting: Coupling : DC.
Vertical sensitivity: 0O.5V/div.
Horizontal time base: 2 mS/div.

Load the test disc and put the unit into the PLAY mode.
Adjust RV103 so that the tracking error waveform is symmetrical.
(See Fig 3)
z
NOTE: BEFORE CONTINUING REFER TO PAGE 8 FOR GUIDANCE ON FOCUS AND
TRACKING GAIN ADJUSTMENT.
Focus gain adjustment
Switch the special jig to “OFF" and leave the scope connected.
Scope settings: Coupling - DC
Vertical sensitivity: 0.1V/div
Horizontal timebase : 2mS/div
Adjust RV105 so that the DC level is between 120 and 200mv.
Turn the power OFF,remove the jig and return the original socket to
Piti.
Tracking gain adjustment
Turn the power ON, load the test disc and press PLAY.
Connect the scope to pin 3 of P1111.
Scope setting: Coupling : DC
Vertical sensitivity: O.2v/div
Horizontal timebase : 2mS/div
Adjust RV104 so that the waveform is as shown in Fig 4(a).
FiG.. 4
"TO SCOPE
od.
<a

FIG.2(a)
FIG.2(b)
Poor
eye
pattern
ae 4T 5T - W1T
/
vee oF
FIG.2(c) Good eye pattern
ee ee ee ee ee ee ee ee ee ee ee ee ee oe
|
Volt/div:
0.2
V
|
ae
|
Time/div:
2
mS
: Ar a ae tae
ng tN i y yee ne '
Blain
es OV
a Se
way
Per
geal
Y
eu
tau
ae ! Vk .
\
FIG.4(b) High tracking gain
(higher frequency than for low gain)
2
|
my
nN
HL
,
Volt/div:
0.2
V
Me
a
Time/div:
2
ms
li
iP
iy
. : ai, ue as | mv @) V
F Ly |
Mt
ih
if
"
\,
mer
(it
\
! f
i Nis ie MN nn
FIG.4(c) Low tracking gain
Volt/div: 0.2 V
Time/div: 2 mS
OV

FOCUS/ TRACKING GAIN ADJUSTMENT
NOTE: It is recommended that these adjustment are not carried out unless
absolutely necessary.
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 3
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.
*x When the gain is too low,the susceptibility to mechanical shock and
skipping will be poor.
ere we ree wee ee eee ce ee eee es ee ee ee eee ee ee ees ee ee eee eee ee eee eee ee a i en tl
— ee cee ee eee ee ee ee ee ee ee ee eee eee ee ee ee ee ee eee es ee eee eee eee ~~ <a ee ee ee ee eee ee —— a oe oe oe eee ae ae ee
Time taken from stop to play is excessive, or
track skip time is excessive.
(normally approx. 2 sec)
Music does not start when play 1s pressed or
track selection is made but disc rotates.
— eee ee ee ee ee ieee ee ee ee ee ee ee ee ee ee eee ee ee ee eee ce ees eee eee ee eee eee —— a a ee eee ee eee eee ee ee —_ a a ee ee ee ee eee ee
ee eee ee ee ee ee eee eee eee eee eee eee eee eee ee eee eee — ere ote ee ee ae ee eee eee ee ieee ee oe =r a CP ee ee ee ee eee eee ee
Intermittent sound during play or counter.
stops.
High mechanical noise from optical block
during play.
low or high low or high
TOW
low or high
low
high high
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11
PRECAUTIONS
WHEN
CHANGING
LASER
PICK-UP
!!
When
removing
pick-up
assembly,
short
circuit
the
PCB
pattern
as
shown
in
the
drawing
in
order
to
protect
the
pick
up
before
removal.
NOTE:
Replacement
pickup
assemblies
are
supplied
with
the PCB
pattern
already
protected.
DO
NOT
REMOVE
THE
SHORT
CIRCUITS
UNTIL
YOU
HAVE
FINISHED
FITTING
THE
PICKUP.
*PICKUP REPLACEMENT*
1.
Push
OPEN/CLOSE
button
to
open
the
disc
tray.
2. Remove the tray door.
3.
Push
OPEN/CLOSE
button
to
close
the
disk
tray.
4.
Disconnect
the
AC
mains
supply.
5.
Remove
the
front
panel
and
mechanism
from
the
chassis.
6.
Before
removing
the
mechanism
note
the
precautions
listed
above.
7.
Remove
screws
ABCD
to
release
the
pickup
assembly.