Many electrical and
mechanical parts in this chassis have special characteristics. These
characteristics often pass unnoticed and the protection afforded by them cannot
necessarily be obtained by using replacement components rated for higher
voltage, wattage, etc. Replacement parts that have these special safety
characteristics are identified in this manual and its supplements; electrical
components having such features are identified by the mark " ! "
in the schematic diagram and the parts list.. The use of substitute replacement
parts that do not have the same safety characteristics as specified in the
parts list may create shock, fire, or other hazards.
Manual Procedure
to remove the tape from the loader (How to take out the tape at emergency)
Immediate action must be done to remove the
Video Cassette on the set manually as described below :
Note : Item number refers to the Deck Parts List in VCR Module (12NC:2422 549
01124) unless otherwise stated
* Turn the B525 (LDG Belt MK11 ) in the
direction indicated by the arrow below in figure.
* Upon hearing the click sound , the
Clip[B587] holding the VCR will be released as shown.
* The tape will be slackened as shown.
* The video cassette slowly reversed and
raised to loading position.
* Fold the slack of the video by hand to
minimize damage by the front dust cover of Video cassette. The front cover upon
approaching the B354 & B355 position will be closed and comes out of the
Door Flap(112 of exploded view of DVDR3430V).
* Remove the cassette as you normally do from
the front loading position.
Mechanical alignment procedures
Method for Manual
Tape Loading - Unloading
To load a cassette tape manually:
1. Disconnect the AC plug.
2. Remove the Top Case and Front Assembly.
3. Insert a cassette tape. Though the tape will not be automatically loaded,
make sure that the cassette tape is all the way in at the inlet of the Cassette
Holder. To confirm this, lightly push the cassette tape further in and see if
the tape comes back out, by a spring motion, just as much as you have pushed
in.
4. Turn the LDG Belt in the appropriate direction shown in Fig. M1 for a minute
or two to complete this task.
To unload a cassette tape manually:
1. Disconnect the AC plug.
2. Remove the Top Case and Front Assembly.
3. Make sure that the Moving guide preparations are in the Eject Position.
4. Turn the LDG Belt in the appropriate direction shown in Fig. M1 until the Moving guide preparations come to the Eject Position. Stop turning when the preparations begin clicking or cannot be moved further. However, the tape will be left wound around the cylinder.
5. Turn the LDG Belt
in the appropriate direction continuously, and the cassette tape will be
ejected. Allow a minute or two to
complete this task.
Method to place
the Cassette Holder in the tape-loaded position without a cassette tape
1. Disconnect the AC Plug.
2. Remove the Top Case and Front Assembly.
3. Turn the LDG Belt in the appropriate direction shown in Fig. M1. (The Cam
Gear in Fig. M2 rotates.) Release the locking tabs shown in Fig. M1 and
continue turning the LDG Belt until the Cassette Holder comes to the
tape-loaded position.
Allow a minute or two to complete this task.
Preliminary - final
Checking and Alignment of Tape Path
Symptom of
Misalignment
If the tape path is unstable, the tape will be damaged.
Note: Do not use an Alignment Tape for this procedure. If the unit is
not correctly aligned, the tape may be damaged.
1. Playback a blank cassette tape and check to see that the tape runs without
creasing at Guide Rollers [2] and [3], and at points A and B on the lead
surface. (Refer to Fig. M3 and M4.)
2. If creasing is apparent, align the height of the guide rollers by turning
the top of Guide Rollers [2] and [3] with a Guide Roller Adj. Screwdriver.
(Refer to Fig. M3 and M5.)
3. Check to see that the
tape runs without creasing at Take-up Guide Post [4] or without snaking between
Guide Roller [3] and ACE Head. (Fig. M3 and M5)
4. If creasing or snaking is
apparent, adjust the Tilt Adj. Screw of the ACE Head. (Fig. M6)
X Value Alignment
If the Horizontal Position
of the ACE Head is not properly aligned, maximum PB FM envelope cannot be obtained
at the preset position of the Tracking Control Circuit.
1. Connect the
oscilloscope to TP301 (C-PB) and TP503 (CTL) on the Main CBA. Use TP504 (RFSW)
as a trigger.
2. Playback the Gray
Scale of the Alignment Tape (9965 000 14515) and confirm that the PB FM signal
is present.
3. Set the Tracking
Control Circuit to the preset position by pressing “CH UP” button and then
“VCRPLAY” button on the unit.
4. Use the Flat
Screwdriver so that the PB FM signal at TP301 (C-PB) is maximum. (Fig. M6)
5. To shift the CTL
waveform, press “CH UP” or “CH DOWN” button on the remote control unit. Then make
sure that the maximum output position of PB FM envelope signal becomes within
±2ms from preset position.
6. Set the Tracking Control
Circuit to the preset position by pressing “CH UP” button and then “VCRPLAY”
button on the unit.
Checking/Adjustment
of Envelope Waveform
To achieve a satisfactory picture, adjust the
Guide Rollers so that the PB FM envelope becomes as flat as possible.
Symptom of Misalignment
If the envelope output is poor, noise will appear in the picture.
The tracking will then lose precision and the playback picture will be distorted
by any slight variation of the Tracking Control Circuit.
1. Connect the oscilloscope to TP301 (C-PB) on the Main CBA. Use TP504 (RF-SW)
as a trigger.
2. Playback the Gray Scale on the Alignment Tape (9965 000 14515). Set the
Tracking Control Circuit to the preset position by pressing “CH UP” button and
then “VCR-PLAY” button on the unit. Adjust the height of Guide Rollers [2] and
[3] (Fig. M3, page 4-
6) watching the oscilloscope display so that the envelope becomes as flat as
possible. To do this adjustment, turn the top of the Guide Roller with the
Guide Roller Adj. Screwdriver.
3. If the envelope is as shown in Fig. M8, adjust the height of Guide Roller
[2] (Refer to Fig. M3) so that the waveform looks like the one shown in Fig.
M10.
4. If the envelope is as shown in Fig. M9, adjust the height of Guide Roller
[3] (Refer to Fig. M3) so that the waveform looks like the one shown in Fig.
M10.
5. When Guide Rollers [2]
and [3] (Refer to Fig. M3) are aligned properly, there is no envelope drop either
at the beginning or end of track as shown in Fig. M10.
Note: Upon completion of the adjustment of Guide Rollers [2] and [3]
(Refer to Fig. M3), check the X Value by pushing the “CH UP” or “CH DOWN”
buttons on the unit alternately, to check the symmetry of the envelope. Check
the number of pushes to ensure preset position. The number of pushes of the “CH
UP” button on the unit to achieve 1/2 level of envelope should match the number
of pushes of the “CH DOWN” button on the unit from center. If required, redo the “X Value Alignment.
Azimuth Alignment
of Audio/Control - Erase Head
To correct the Azimuth alignment so that the
Audio/Control/Erase Head meets tape tracks properly.
Symptom of Misalignment
If the position of the Audio/Control/Erase Head is not properly
aligned, the Audio S/N Ratio or Frequency Response will be poor.
1. Connect the oscilloscope to the audio output jack on the rear side of the
deck.
2. Playback the alignment tape (9965 000 14515) and confirm that the audio
signal output level is 8kHz.
3. Adjust Azimuth Adj. Screw so that the output level on the AC Voltmeter or
the waveform on the oscilloscope is at maximum. (Fig. M6)
Note: Upon completion of the adjustment of Azimuth Adj. Screw, check the
X Value by pushing the “CH UP” or “CH DOWN” buttons on the unit alternately, to
check the symmetry of the envelope. Check the number of pushes to ensure preset
position. The number of pushes of the “CH UP” button on the unit to achieve 1/2
level of envelope should match the number of pushes of the “CH DOWN” button on
the unit from center. If required, redo the “X Value Alignment.”
Checking and
Alignment of Tape Path during reversing
Purpose: To make sure that the tape path is well stabilized
during reversing.
Symptom of Misalignment. If the tape path
is unstable during reversing, the tape will be damaged.
Note: Do not use an Alignment Tape for this procedure. If the unit is
not correctly aligned, the tape may be damaged.
1. Insert a blank cassette tape into the tray and set the unit to REV. Then
confirm if the tape has been curled up or bent at the Take-up Guide Post[4] or REV
Post[5]. (Refer to Fig. M11 and M12.)
2. When the tape has been curled up or bent, turn the alignment screw to adjust
the height of REV Post. (Refer to Fig. M11 and M13.)
