Technics RS-TR474

| RS-TR4;
HWRITING TO EEPROM __.
This
unit
is
equipped
with
EEPROM
memory
that
stores
a
variety
of
design
data
and
performance
data
such
as
playback
gain,
bias
value,
recording
gain,
recording
equalization,
etc.,
which
was
programmed
at
the
factory.
This
EEPROM
memory
is
capable
of
being
read
and
written
to
more
than
100,000
times.
To
illustrate
this,
if
one
ATC
operation
is
performed
every
hour
continuously
every
day
for
ten
years,
it
world
still
be
possible
to
successfully
read
and
write
with
the
EEPROM.
Data
is
actually
written
in
this
EEPROM
only
when
ATC
is
actuated
or
when
power
aupply
is
turned
on
or
off.
.
Since it hardly breaks down, there will scarcely occur such a trouble as to require replacement.
Measurement Condition
¢ Recording-level control; Maximum * Make sure heads are clean
¢
Recording-balance
control;
Center
¢
Make
sure
capstan
and
pressure
roller
are
clean
_
e Reverse-mode selector switch; = ; ¢ Judgeable room temperature 20+5°C (68+9°F)
¢ Tape-to-tape recording-speed switch; Off :
¢ Dolby NR switch; Off
¢ ATC switch; Off
Measuring instrument
e EVM (Electronic Voltmeter) ¢ ATT (Attenuator)
¢ Oscilloscope ¢ Resistor (600Q)
° AF oscillator : ;
NOTE: Before adjustment, be sure to set the AF oscillator output level to OdB (1kHz): 1V
Test tape es
¢ Playback gain adjustment (315Hz, 0dB); QZZCFM ...
* Overall gain adjustment and Overall} frequency response
Normal reference blank tape; QZZCRA
CrO, reference blank tape; QZZCRX1
Metal reference blank tape; QZZCRZ5
NOTE: Step 1 to step 7 only has to be done after exchange of the EEPROM.
Short the Test Mode terminals with a shorting clip.
Step 1
OPERATION PC.B.
Step 2 While holding down the STOP button on DECK2, press the POWER Y
Pp :
switch to ON.
All FL display segments except for the four-digit counter on DECK2 Short Clip
will start blinking to indicate that the deck has entered Write mode.
At this point the four-digit counter will indicate “OQ-k”.
Step 3
Notes:
* The test mode terminals
on main P.C.B. should be
shorted with a short clip
as shown above figure.
« After the adjustment
items disconnect the
short clip.