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RN-190
REPLACING THE MAIN PARTS OF THE MECHANISM
UNIT
¢To remove the mechanism
unit, see the section "DISASSEMBLY
INSTRUCTION".
A. How to replace the motor assembly.
assembly. (See Fig. 1.)
. Mount the motor assembly so that its lead wires
direct as shown in Fig. 1.
Wire
2
Motor
B. How to replace record/playback head
Record/Playback Head
hm —
. Remove the pinch roller spring as shown in Fig. 2.
. Remove the poly washer (B) to remove the pinch
roller arm assembly. (See Fig. 2.)
3. Remove
two
screws
(C) to remove
the
record/
playback head. (See Fig. 2.)
4. When
the
record/playback
head
is_ installed,
reverse the disassembly procedure above.
5. Readjust the head, referring to measurement and
adjustment in this service manual.
face eta ot
7
\
|
Pinch Roller Spring
|
a
eWhen
installing
the
printed
circuit
board
on
the
Printed Circuit
mechanism unit, note the following:
Board
Check
that the record/playback
(S1) and
fast forward/
rewind (S4) switches are placed in their specified posi-
tions as shown in Fig. 3.
Mechanism
Unit
Switch Lever
Fig. 3
MEASUREMENT AND ADJUSTMENT METHODS
NOTES:
Keep good condition, set switch buttons and controls in the following positions, uniess otherwise
specified.
eVAS switch: OFF
e Make sure heads are clean.
e Volume control: Maximum
e Make sure capstan and pinch roller are clean.
eTape speed select switch: 2.4cm/s, 1.2cm/s
e Judgeable room temperature: 20+5°C (68+9°F)
eFF/REW switch: OFF
Azimuth Adjustment Screw
@®
Head Azimuth
. Assemble thé mechanism and cabinet parts completely.
Adjustment
. Play back the head azimuth adjusting tape (2.4cm/s, 3kHz...QZZMWA).
e
a
_ Adjust the azimuth adjusting screw (Refer to Fig. 2) of Record/Playback
11 (|
* Playb
k
d
head to obtain the maximum
monitor output.
ey
ay RACK MOR.
. After adjusting, repeat PLAY and STOP some times and confirm that the
Equipment:
output variation is less than the specified level (within 3dB).
* Test tape
R/P Head
..
QZZMWA
;
:
Fig. 2
©
Tape speed
. Test equipment connection is shown in fig. 1.
adjustment
. Apply 3V to DC IN.
Condition:
. Connect the monitor output (822) to the counter.
* Playback mode
. Playback
the tape speed
adjusting
tape (for
:
2.4cm/s
3kHz,
QZZMWA,
for
1.2CM/S oc power supply Playback mode
Equipment:
QZZMWBL).
* DC power supply
. Measure this frequency.
Fig. 1
* Digital electronic
bert
iee for
6. If measured value is not within standard, adjust as follows.
..QZZMWBL for
A) 2.4cm/s adjustment
1.2cm/s
1. Set the tape speed selector switch (S2) to 2.4cm/s.
2. Adjust tape speed adjustment
VR3 so that frequency is 2940+ 20Hz.
3. Refer to Fig. 3.
B) 1.2cm/s adjustment
1. Set the tape speed selector switch (S2) to 1.2cm/s.
2. Adjust tape speed adjustment VR2 so that frequency is 2940+ 20Hz.
3. Refer to Fig. 3.
Digital electronic counter
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