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DR-E22BK
DR-E22LBK
Troubleshooting
1. The tuner block is independent.
The tuner block only receives the + 12 V, — 12 V (lamps
only), and
+5 V power supplies and ground with the
FW 201 flat wire, outputs the left and right signals, and
receives control signals through the DCS line.
When a tuner key is pressed, the DCS cutputs the source
switch reqest and interprets the contents of the tuner
keys operated by the switch control, converting the con-
- tents of the key signals into DCS codes with the system
control.
microcomputer.
When
repairing
other
parts,
removing the tuner block makes repairs easier and the
machine can still be run for testing.
Note:
Since the chassis of this unit is grounded through
the tuner board, when removing the tuner board,
ground the chassis with an alligator clip or similar
device.
, The system microcomputer and the mechanism control
microcomputer are closely related. In order to understand
the state of the mechanism, the system microcomputer
is constantly
receiving
mechanism
data
from
the
mechanism
control microcomputer.
Therefore,
if the
mechanism is not normal, the system microcomputer will
not function. The mechanism control microcomputer has
the mechanism operate according to the control words
received from the system microcomputer to control the
deck amp system. Of particular importance are the cam
motor control and the cam position data input, describ-
ed above.
The system microcomputer waits for the source deck key
input, DCS input, and remote control input, controls serial
data for the source select LSI, the serial data for the
mechanism control microcomputer, and the DCS serial
data, and controls the source display, mechanism status
display, capstan motor, muting, and main electric level
settings.
. The deck's mechanism is a double mechanism compris-
ing an A mechanism (playback only) and a B mechanism
(recording/playback). In this deck, the mechanical swit-
ches, the motor (reel, CAM) connections, and the motor
drive circuit are installed in the mechanism section and
connected with.a 20-pin socket. If this socket is remov-
ed, the
mechanical
contro!
microcomputer
and
the
system microcomputer will not work.
Note:
The deck's mechanical section is grounded via the
bottom plate, so if the bottom plate is removed
to check operations (especially signals), ground
the mechanical section with an alligator clip or
similar device. Also, since pack detection is us-
ed, the deck will not operate without a tape.
4. When headphones are inserted, the relay is switched off.
Head phones are used with a different gain for IC307,
normally used as the buffer amp. When the plug for a
set of headphones is inserted, the relay is switched off,
the output is muted, and the circuits switch to the head
phone amp.
.
5
oe
Note:
If the FW307 is removed, the relay can not coms
on.
. Concerning
the microcomputer
processing
when
the
power is switched on
As was explained earlier, in this deck the system con-
trol
microcomputer
and
the
mechanical
control
microcomputer
are intimately
linked,
but their basic
clocks are different. When the power is switched on, the
mechanical control microcomputer is initialized, then it
waits for instructions from the system microcomputer.
The system microcomputer first makes the Volume in-
dicators
blink.
Next,
it. communicates
with
the
mechanical control microcomputer to find out its status.
If the status of the mechanical control microcomputer
is normal, the system microcomputer displays the source
and-the status of the system microcomputer. Thus, the
entire system operates.
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