NAD 5420 - Alignment Procedures; PLL Adjustment; RF Adjustment; EF Balance Adjustment

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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.