Panasonic RN-190 - Page 4

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.
Flywheel
Ass’y
Flywheel
Belt
1.
Remove
two
screws
(A)
to
remove
the
motor
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
counter
Standard
value:
2940+
20Hz
(2.4cm/s),
2940+
20Hz
(1.2cm/s).
*
Test
tape
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