DANGER - LASER RADIATION WHEN OPEN.
AVOID DIRECT EXPOSURE TO BEAM.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION:
TO PREVENT ELECTRIC SHOCK, MATCH
WIDE BLADE OF PLUG TO WIDE SLOT,
FULLY INSERT.
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER (OR BACK).
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
The lightening flash with arrowhead symbol,
within an equilateral triangle, is intended to
alert the user to the presence of uninsulated
“dangerous voltage” within the product's enclosure that may be of sufficient magnitude to
constitute a risk of electric shock to persons.
“WARNING”
“TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.”
SAFETY INSTRUCTIONS
Read instructions - All the safety and operating instruc-
1.
tions should be read before the appliance is operated.
Retain instructions - The safety and operating instructions
2.
should be retained for future reference.
Heed warnings - All warnings on the appliance and in the
3.
operating instructions should be adhered to.
Follow instructions - All operating and use instructions
4.
should be followed.
Water and Moisture - The appliance should not be used
5.
near water - for example, near a bathtub, washbowl,
kitchen sink, laundry tub, in a wet basement, or near a
swimming pool, and the like.
Carts and Stands - The appliance should be used only
6.
with a cart or stand that is recommended by the manufacturer.
An appliance and cart combination should be moved with
care. Quick stops, excessive force, and uneven surfaces
may cause the appliance and cart combination to overturn.
Wall or Ceiling Mounting - The appliance should be
7.
mounted to a wall or ceiling only as recommended by the
manufacturer.
Ventilation - The appliance should be situated so that its
8.
location or position does not interfere with its proper ventilation. For example, the appliance should not be situated on a bed, sofa, rug, or similar surface that may block
the ventilation openings; or, placed in a built-in installation, such as a bookcase or cabinet that may impede the
flow of air through the ventilation openings.
ATTENTION:
POUR ÉVITER LES CHOCS ÉLECTRIQUES,
INTRODUIRE LA LAME LA PLUS LARGE DE
LA FICHE DANS LA BORNE CORRESPONDANTE DE LA PRISE ET POUSSER
JUSQU' AU FOND.
The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and maintenance (servicing) instructions in the literature
accompanying the appliance.
Heat - The appliance should be situated away from heat
9.
sources such as radiators, heat registers, stoves, or other
appliances (including amplifiers) that produce heat.
Power Sources - The appliance should be connected to a
10.
power supply only of the type described in the operating
instructions or as marked on the appliance.
Grounding or Polarization - The precautions that should
11.
be taken so that the grounding or polarization means of
an appliance is not defeated.
Power Cord Protection - Power supply cords should be
12.
routed so that they are not likely to be walked on or
pinched by items placed upon or against them, paying
particular attention to cords at plugs, convenience receptacles, and the point where they exit from the appliance.
Cleaning - The appliance should be cleaned only as rec-
13.
ommended by the manufacturer.
Nonuse Periods - The power cord of the appliance should
14.
be unplugged from the outlet when left unused for a long
period of time.
Object and Liquid Entry - Care should be taken so that
15.
objects do not fall and liquids are not spilled into the enclosure through openings.
Damage requiring Service - The appliance should be ser-
16.
viced by qualified service personnel when:
The power supply cord or the plug has been damaged;
A.
or
Objects have fallen, or liquid has been spilled into the
B.
appliance; or
The appliance has been exposed to rain; or
C.
The appliance does not appear to operate normally or
D.
exhibits a marked changed in performance; or
The appliance has been dropped, or the enclosure
E.
damaged.
Servicing - The user should not attempt to service the ap-
17.
pliance beyond that described in the operating instructions. All other servicing should be referred to qualified
service personnel.
Adjusting procedures are given in this manual which also includes a Parts List and circuit diagrams to
*
assist the service technician in maintaining the Model CR200.
*
The following accessory is supplied with CR200 as a standard.
Owner's manual, CR200: 8288407000 (for export model)
Remote control unit Model 8317: 8270829000
Audio cable (L : 1.2m): 8276912000
Power cable: 8276910000 (for USA model)
: 8276911000 (for EUR model)
Following is the packing material for the Model CR200.
Parts marked with this sign are safety critical components. They must always be replaced with identical
!
components. Refer to the Fostex Parts List and ensure exact replacement.
3
CR200
1. CD-R THEORY
1-1. Physical layout compared to CD
The conventional CD and CD-R discs basically have the same
physical layout. However, as you can see from the Fig. 1,
comparing to the conventional CD, the CD-R disc also has socalled “minus” areas such as PCA (Power Calibration Area) and
PMA (Program Memory Area) where the temporary information
is recorded.
Φ120
max Φ118
Φ44.7
min Φ33
min Φ26
Φ15
hole
Clamping
area
Pregroove area with address (ATIP)
Center
Layout of unrecorded CD-R disc
Information area
• Unrecorded, blank disc
The information area is located next to the clamping area and the
center hole. This area contains a pregroove with CLV (Constant
Linear Velocity) clocking information and a time code.
• Partially recorded disc
The CD-R system gives the opportunity to record a disc in several
actions at a different time on a different recorder. After the first
recording, the information area is divided into five parts as shown
below and in the right.
1: Power Calibration Area (PCA)
2: Program Memory Area (PMA)
3: Lead-in Area
4: Program Area
5: Lead-out Area
• Finalized disc
After finalizing the disc, the CD-R disc will become compatible
with the RED Book (for regular CD) definitions and specifications.
Therefore, it can be played back on conventional CD players. The
Information Area of a finalized disc consists of three parts:
1: Lead-In Area
2: Program Area
3: Lead-Out Area
max Φ118
max Φ116
Φ50
Φ46
Φ44.7
PCA
Table Of Contents (TOC)
temporary
PMA
MUSIC
Program
Area
Lead-in Area
recorded
part
Recordable
User Area
+ Lead-out Area
Layout of partially recorded CD-R disc
max Φ118
max Φ116
Φ50
Φ46
final Table of Contents (TOC)
Lead-in Area
recorded part
MUSIC
Program Area
Layout of recorded CD-R disc
max Φ118
max Φ116
Φ50
Φ46
recorded part
MUSIC
TOC
Layout of conventional CD disc
Lead-out
Area
Lead-out
Area
Fig. 1 Cross Section of CD-R & CD Disc
4
1-2. Pregrooved track wobbling + ATIP
When manufacturing the CD-R disc, it has been ÒpregroovedÓ. This pregroove in the CD-R disc is not a perfect spiral but
is wobbled so that the CD-R disc can be recognized by a CD-R recorder even when it is completely blank.
It has many purposes. It not only helps keep the servo on an exact tracking of outgoing spiral but also the demodulated
wobbling frequency contains the time information in digital format (21.05 kHz = Ò0Ó, 23.05 kHz = Ò1Ó). These frequencies
have been selected so that the mean frequency is equal to Fs / 2 (= 22.05 kHz). Also the interleaved is the manufacturer's
measured default laser power level.
0.6µm
(track width)
1.6µm
(track distance)
CR200
22.05 ± 1kHz = ~ 60µm
Fig. 2 Structure of Pregrooved Disc
1-3. PCA + consequence
Each recorder has a tolerance in the laser power and the dye from different manufacturers varies. In order to optimize the
recorder / disc combination, there is a PCA (Power Calibration Area) included in the CD-R disk. This area consists of two
parts, the Count Area and Test Area. In the Test Area, test recordings are made, stepping through several power levels. After
playing back the recorded test signal, the optimum level is automatically determined. This value is memorized until the disk
tray is opened. The Count Area keeps the track on how many of the test areas have been used indicating where to start the
next test. The PCA is designed to accommodate for 100 tests. When the PCA is full, the default value written in the wobbled
groove is used instead.
Test Area
PCA
Count Area
PMA
Lead In
Area
Partition
100
98
4321
98
531
Fig. 3 Organization of PCA, PMA and Lead-In Area
CAUTION :
Every time the CD-R disc is inserted, one test is performed. Also if you leave the disc in the recorder at power off, a test will
be performed when powering on. This might lead to the situation that the PCA might be fully used up even if there is a
remaining space to record audio signal. The recordings made after the PCA is fully used up will not be optimal in performance.
5
CR200
6
6
6
1-4. CD-R Disc Structure and Bubbling Process
Label
The materials of CD-R disc consists of label,
protective layer, reflective layer, organic dye
layer and transparent substrate.
2345678901234567890123456789012123456789012345
2345678901234567890123456789012123456789012345
2345678901234567890123456789012123456789012345
Transparent
UV protective layer
Refective layer
Organic dye layer
substrate
Land
Groove
Laser beam
Fig. 4 Cross Section of CD-R disc
During recording, the laser is tracing the wobbled groove. When a pit is to be recorded, the laser fires off a high power beam
and the organic dye will become black and deformed. This is the way a Ònon-reflectiveÓ part is created. When a groove is
to be recorded, the laser is not fired and the high-reflective surface is maintained. If the data word contains successive the
same information (e.g. 111 or 000), the pit will be continuous. When the data word contains changes, the pit - groove status
will also change.
• Recording Principle
A high power laser beam is shot.
• Playback Principle
NO PITS
A low power laser beam is shot
and high reflectance is obtained.
Organic dye becomes black
and pit is created.
ON PITS
A low power laser beam is shot
and only low reflectance is obtained.
Fig. 5 Recording & Playback Principle
1-5. Finalize
In order to be playable on an ordinal CD-player, the CD-R disc must have a corresponding data for TOC (Table Of Contents).
This area is not used until all the recording is completed. Instead, a special area called PMA (Program Memory Area) is used.
When the disk is full or all the recording is completed, the disk can be finalized. This means that the temporary information
in the PMA is checked and transferred to TOC. Now the disk is playable on an ordinal CD player but it will not be recordable
any more.
6
2. SPECIFICATIONS
FUNCTIONS
Sampling rate converterFs : 48 kHz / 32 kHz → 44.1 kHz
Automatic disk distinction
Time display switching
Synchronous to one song / All songs / DAT ID
REC mute
Automatic power calibration
Automatic track increment
Manual track increment
Automatic REC PAUSE
PreviousEnd section of previous track can be reproduced during REC
PAUSE mode.
Fader in / fader outCan be controlled only by infra-red remote controller
Disk remaining time display
Sampling monitor
Skip play
Track skip on / offCan be controlled only by main unit key
One song / all songs program repeatCan be controlled only by infra-red remote controller
Program play
Manual search
Track search
Direct searchCan be controlled only by infra-red remote controller
Program setting / clearCan be controlled only by infra-red remote controller
Input sensitivity switchSW 1 (+4 dBu / -8 dBu, rear panel)
Infra-red remote controller on / off switchSW 2 (rear panel)
Digital out on / off switchSW 2 (rear panel)
Copy bit setting switchSW 2 (No restriction / One time only / Prohibited, rear panel)
CR200
FL DISPLAY CONTENTS
PLAY
REC
PAUSE
REPEAT
1-REPEAT
AUTO TRACK No.
PROGRAM
TOC
Level meter
Track number
Input sampling frequency
Elapsed time
Remaining time
Total time
Remaining record time
7
CR200
GENERAL
ModelCompact disc recorder
Applicable discsCDs and CD-Rs
Number of channels2 channels (stereo)
Power supplyAC 120 V, 60 Hz
AC 220 ~ 230 V, 50 / 60 Hz
Power consumption21 W
Weight (without package)6.2 kg / 13.7 lbs
Maximum dimensions482 (W) x 134 (H) x 294 (D) mm
18-31/32 (W) x 5-9/32 (H) x 11-9/16 (D) inch
AUDIO UNIT
Playback (CD)
Frequency characteristics4 Hz ~ 20 kHz ± 1.0 dB
S/N83 dB or more (EIAJ)
Dynamic range83 dB or more (EIAJ)
Total harmonic distortion0.01 % or less (EIAJ)
Channel separation90 dB or more (EIAJ)
De-emphasis deviation0 ± 1.5 dB or less (EIAJ)
Level difference between channels1.0 dB or less (EIAJ)
Output voltage2.4 V ± 0.3 V rms
Monitoring (analog RCA pin input)
Frequency characteristics4 Hz ~ 20 kHz ± 1.0 dB
S/N83 dB or more (EIAJ)
Dynamic range83 dB or more (EIAJ)
Total harmonic distortion0.01 % or less (EIAJ)
Maximum input level3.2 V rms or more
Minimum input level0.4 V rms or less
Record & Playback (analog RCA pin input)
Frequency characteristics4 Hz ~ 20 kHz ± 1.0 dB
S/N83 dB or more (EIAJ)
Dynamic range83 dB or more (EIAJ)
Total harmonic distortion0.01 % or less (EIAJ)
Monitoring (Digital coaxial input)
Frequency characteristics4 Hz ~ 20 kHz ± 1.0 dB
S/N95 dB or more (EIAJ)
Dynamic range90 dB or more (EIAJ)
Total harmonic distortion0.01 % or less (EIAJ)
Maximum input level0.6 V rms or more
Minimum input level0.2 V rms or less
Record & Playback (Digital coaxial input)
Frequency characteristics4 Hz ~ 20 kHz ± 1.0 dB
S/N90 dB (analog) / 105 dB (digital)
Dynamic range90 dB (analog) / 95 dB (digital)
Total harmonic distortion0.01 % (analog) / 0.003 % (digital)
Even if nothing is wrong with the pickup section and hardware components in the circuits, due to the misalignment of
various adjustments, there is a possibility that the CR200 does not work properly or at all. According to the following
procedures, make adjustments correctly.
Test equipment and adjusting tools
• Dual trace oscilloscope, 100MHz or higher bandwidth
• Sinewave signal generator
• Test disk: TCD-785 (Almedio) and STD-R03 (Pioneer)
• Low pass filter
15k½ + 0.001µF x 2 pcs.
39k½ + 0.001µF x 1 pc.
• High pass filter
3.9k½ + 180pF x 1 pc.
• Resistor
100k½
• Hex wrench: 1.27mm diagonal
• Regular tools such as a pair of tweezers, cutter, long-nose pliers and minus screw driver
• Ceramic screw driver. Vessel 9000 series are recommended.
• Digital multimeter (measuring voltage: less than 1mV)
Table of adjusting item / test point / pot
Adjustment 1
No.
Playback power adjustment
1
Coarse focus offset adjustment
2
Coarse skew adjustment
3
Coarse grating adjustment
4
DPP (tracking offset) adjustment
5
Fine focus offset adjustment
6
Fine skew adjustment
7
Grating readjustment
8
Item
Test Point
CN104 Pin-7 (PWAJT)
CN204 Pin-1 (RF)
CN204 Pin-1 (RF)
(1) Use a 10 : 1 probe for the oscilloscope.
(2) All the knob positions (settings) for the oscilloscope in the adjustment procedures are for when a 10 : 1 probe is used.
Test Mode
This model has a test mode so that the adjustments and checking required for servicing can be carried out easily.
When this model is put into test mode, the keys on the front panel would work differently from normal condition.
Adjustments and checks can be carried out by operating these keys with the correct procedures. On this model, all
adjustments are carried out in test mode.
[ Setting to Test Mode ]
The way to set this model into test mode.
(1) Plug the power cord back into the AC socket.
(2) Shorten the test mode lands. (See Fig. 6.)
(3) Press the Power SW ON.
When the test mode is set correctly, the display is different from what it usually is when the power is turned on. (lights up
all FL display) If the display is still the same as usual, test mode has not been set correctly, so repeat Steps 1 Ð 3.
CR200
[ Release from Test Mode ]
Here is the procedure for releasing the test mode.
(1) Press the STOP key and stop all operations.
(2) Press the Power SW OFF.
[ Operations of the Keys in Test Mode ]
Code Key Name Function in Test ModeExplanation
DIGITAL
SYNCHRO
FINALIZE
PLAY
PAUSE
Playback laser diode ONLights up the laser diode by playback power.
The laser diode is lit up and the focus actuator is lowered,
then raised slowly and the focus servo is closed at the point
where the objective lens is focused on the disc.
With the player in this state, if you slightly rotate the stopped
Focus servo closes
Spindle servo ON
Tracking servo close/open
disc by hand, you can hear the sound of focus servo. If you
can hear this sound, the focus servo is operating correctly.
If you press the key with no disc mounted, the laser diode
lights up, the focus actuator is pulled down, then the
actuator is raised and lowered three times and returned to
its original position.
Starts the spindle motor in the clockwise direction and when
the laser rotation reaches the prescribed speed (about 500
rpm at the inner periphery), set the servo in a closed loop.
Pressing this key when the focus servo and spindle servo
are operating correctly in closed loops puts the tracking
servo into a closed loop, displays the track number being
played back and the elapsed time on the front panel.
If the elapsed time is not displayed or not counted correctly,
it may be that something is out of adjustment, or that there is
some other problem.
This key is a toggle key and open/close the tracking servo
alternately. This key has no effect if no disc is mounted.
15
CR200
y
y
g
CodeKey NameFunction in Test ModeExplanation
Moves the pickup position toward the inner diameter of the
disc. When this ke
MANUAL/
TRACK
•
SEARCH REV
MANUAL/
TRACK
•
SEARCH FWD
STOP
OPEN/CLOSE Disc tra
RECORD
Carriage reverse
(inwards)
Carriage forward
(outwards)
Stop
open/close
Maximum recordin
Laser diode ON
power
REC MUTE
AUTO/
MANUAL
WRITE(MANUAL) LED Lights UP: Optical axis servo ON
TIME0 sec.) of disc.
Focus offset servoCOPY BIT LED Lights UP: C/N in the best condition
Optical axis servo
switching
Search to the lead of disc.
(It works only CD-R use.)
closed loop, the tracking servo automatically goes into an
open loop.
Since the motor does not automatically stop at the
mechanical end point in test mode, be careful with this
operation.
Moves the pickup position toward the outer diameter of the
disc. When this key is pressed with the tracking servo in a
closed loop, the tracking servo automatically goes into an
open loop.
Since the motor does not automatically stop at the
mechanical end point in test mode, be careful with this
operation.
Initializes and the disc rotation stops.
The pickup and disc remain where they are when this key is
pressed.
Open/close the disc tray. This key is a toggle key and
open/close tray alternately.
Pressing this key when the disc is turning stops the disc,
then opens the tray.
This key operation does not affect the position of the pickup.
Lights up the laser diode with maximum recording power and
normal EFM by pressing REC and REC MUTE keys in order.
* The laser diode may be damaged if adjustments are made
before pressing these keys.
Switches the focus offset state.
Lights OFF: Jitter in the best condition
Switches the ON/OFF of the optical axis servo.
Light OFF: Optical axis servo OFF
When using the CD-R disc, search to the lead (0 min.
(It doesn't work in CD disc use.)
is pressed with the tracking servo in a
16
[ How to Play Back a Disc in Test Mode ]
In test mode, each servo operates independently. Thus, it is required to press the keys and close the servo in a correct order
so that a disc can be played
Here is the key operation sequence for playing back a disc in test mode.
FINALIZE
PLAY
PAUSE
Wait at least 2 ~ 3 seconds between each of these operations.
Lights up the laser diode and closes the focus servo.
Starts the spindle motor and closes the spindle servo.
Closes the tracking servo.
4.2 Adjustment 1
4.2.1 Playback Power Adjustment
DANGER - LASER RADIATION WHEN OPEN.
AVOID DIRECT EXPOSURE TO BEAM.
• ObjectiveTo optimize the playback power of the laser diode.
• Symptom when out of adjustmentDoes not start playing, track search is impossible, tracks are skipped.
Press the FINALIZE key and the PLAY key in the order to close the focus servo and then the spindle servo.
(1)
Adjust VR105 (FE. OFS) so that the amplitude of waveform at CN204 (TP201), Pin-1 (RF) is maximum.
(2)
NOTE:
The oscilloscope displays a moving image, not a ÒSTILLÓ image as shown below. In order to verify that the focus
servo is on, tap on the machine gently and listen to the sound indicating the servo operation.
Out of adjustment
(Waveform amplitude is at maximum.)
Optimum adjustment
Fig. 10
18
4.2.3 Coarse Skew Adjustment
• ObjectiveTo coarse adjust the angle of pickup to the disc for performing the grating and
DPP (tracking offset) adjustments correctly.
• Symptom when out of adjustmentSound is cracking, some discs can be played but not others.
• Measurement instrument connections Oscilloscope to CN204, Pin-1 (RF) (SERVO UCOM BOARD assy)
GND probe can be connected to CN204, Pin-4 (AGND).
[ Settings ]: 20 mV/div., 200 nS/div., AC mode
• DiscTCD-785
• Player stateTest mode, focus and spindle servos: closed, tracking servo: open
• Adjustment locationRadial adjustment screw and tangential adjustment screw
CAUTION:
Before executing this adjustment, you must cut a few wire binders, disconnect cable and loosen 4 screws so that the
HEAD BOARD assy can be tilted up and fixed into the slits.
[ Procedures ]
Move the pickup to the position where the radial/tangential adjustment screws will be seen with the MANUAL / TRACK
(1)
SEARCH FWD or REV keys so that the radial/tangential adjustment screws can be adjusted.
Press the FINALIZE key and the PLAY key in the order to close the focus servo and then the spindle servo.
(2)
(3)
Adjust the RAD (radial direction) and TAN (tangential
direction) adjustment screws alternately with hexagonal
screwdriver (1.27 mm diagonal) to maximize the RF output at
CN204 (TP201), Pin-1.
Hexagonal
screwdriver
CR200
NOTE:
Radial direction and tangential direction
mean the direction relative to the disc
shown in Fig. 11.
Radial direction
Tangential direction
Disc
Fig. 2
Radial
adjustment
screw
Tangential
adjustment
screw
FRONT PANEL
Fig. 11
19
CR200
4.2.4 Coarse Grating Adjustment
• ObjectiveTo align the tracking error generation laser beam spots to the optimum angle on
the track.
• Symptom when out of adjustmentDoes not start playing, track search is impossible, tracks are skipped.
• Measurement instrument connections Oscilloscope to CN104, Pin-3 (TE) via a low pass filter.
(HEAD BOARD assy) See Fig. 14 below.
GND probe can be connected to CN104, Pin-4 (AGND).
[ Settings ]: 50 mV/div., 5 mS/div., DC mode
• DiscTCD-785
• Player stateTest mode, focus and spindle servos: closed, tracking servo: open.
• Adjustment locationGrating adjustment screw in the slit
[ Procedures ]
Move the pickup to the position where the grating adjustment slit will be seen with the MANUAL / TRACK SEARCH
(1)
FWD or REV keys so that the grating adjustment can be adjusted.
Press the FINALIZE key and the PLAY key in the order to close the focus servo and then spindle servo.
(2)
Insert a screwdriver into the grating adjustment slit and adjust the grating to find the null point.
(3)
For more details, see next page.
If you slowly turn the screwdriver clockwise from the null point, the amplitude of the wave gradually increases. Then, if
(4)
you continue turning the screwdriver, the amplitude of the wave becomes smaller again. Turn the screwdriver
counterclockwise from the null point and set the grating to the first point where the wave amplitude reaches its maximum.
Reference : Fig. 13 shows the relation between the angle of the tracking beam with the track and the waveform.
Return the pickup to more or less midway across disc with the MANUAL / TRACK SEARCH key. Then, press the
(5)
PAUSE key and check that the track number and elapsed time are displayed on the front panel. If they are not displayed
at this time or the elapsed time changes irregularly, check the null point and adjust the grating again.
Small
screwdriver
Grating
adjustment
CN104
(TP1)
Pin 3
(TE)
Pin 4
(AGND)
HEAD BOARD
ASSY
LPF
15kΩ
0.001
µF
(10 : 1)
screw
20
Fig. 3
Fig. 12
[ How to find the null point ]
Turning the grating counterclockwise
Turning the grating clockwise
Null point
Grating adjustment position
Waveform of
CN104 (TP1), Pin 3 (TE)
Fig. 4
Null point waveformMaximum amplitude
waveform
Waveform other than the
null point
Note : If the difference between the amplitude of the error signal at the
innermost edge and outermost edge of the disc is more than 10%,
adjust the grating again.
When you insert the small screwdriver into the slit for the grating adjustment and change the grating angle, the amplitude
of the tracking error signal at CN104 (TP1), Pin 3 (TE) changes. Within the range for the grating, there are five or six
locations where the amplitude of the wave reaches a minimum. Of these five or six locations, there is only one at which
the envelope of the waveform is smooth. This location is where the three laser beams divided by the grating are all right
above the same track. (See Fig. 13.)
This point is called the null point. When adjusting the grating, this null point is found and used as the reference position.
CR200
Fig. 13
4.2.5 DPP (Tracking Offset) Adjustment
• ObjectiveTo correct for the variation in the sensitivity of the tracking photodiode.
• Symptom when out of adjustmentThe unit does not playback, track search is impossible, tracks are skipped.
• Measurement instrument connections Oscilloscope to CN104, Pin-3 (TE)
[This connection must be via a low pass filter (15kW + 0.001µF). ]
GND probe can be connected to CN104, Pin-4 (AGND).
[ Settings ]: 50 mV/div., 5 mS/div., DC mode
• DiscTCD-785
• Player stateTest mode, focus and spindle servos: closed, tracking servo: open.
Move the pickup to midway across the disc (R = 35mm) with the MANUAL / TRACK SEARCH FWD or REV keys.
(1)
Press the FINALIZE key, the PLAY key and the PAUSE key in the order to close the respective servos and put the player
(2)
into play mode.
Adjust VR105 (FE. OFS) so that the 3T waveform at CN204, Pin-1 (RF) is maximum.
(3)
Out of adjustmentOptimum adjustment
Fig. 15
22
4.2.7 Fine Skew Adjustment
• ObjectiveTo adjust the angle of the pickup relative to the disc so that the laser beams are
shone straight down into the disc for the best read out of the RF signals.
• Symptom when out of adjustmentSound is cracking, some discs can be played but not others..
• Measurement instrument connections Oscilloscope to CN204, Pin-1 (RF) (SERVO UCOM BOARD assy)
GND probe can be connected to CN204, Pin-4 (AGND).
[ Settings ]: 20 mV/div., 200 nS/div., AC mode
• DiscTCD-785
• Player stateTest mode, play
• Adjustment locationPickup radial adjustment screw and tangential adjustment screw
[ Procedures ]
Move the pickup to the position where the radial/tangential adjustment screws will be seen with the MANUAL / TRACK
(1)
SEARCH FWD or REV keys so that the radial/tangential adjustment screws can be adjusted.
Press the FINALIZE key, the PLAY key and the PAUSE key in the order to close the respective servos and put the player
(2)
into play mode.
First, adjust the radial adjustment screw with the hexagonal screwdriver (1.27 mm) so that the eye pattern (the diamond
(3)
shape at the center of the RF signal) can be seen the most clearly and the amplitude is at maximum..
Next, adjust the tangential adjustment screw with the hexagonal screwdriver so that the eye pattern can be seen the most
(4)
clearly. (Fig. 17).
Adjust in the order of the radial adjustment screw and the tangential screw again, so that the eye pattern can be seen the
(5)
most clearly. As necessary, adjust the two screws alternately so that the eye pattern can be seen the most clearly.
After the adjustment, remove the float screw, turn over the servo mechanism assembly, then secure the radial adjustment
screw and the tangential adjustment screw with loc-tite.
(6)
CR200
Stabilize each screw
with an adhesive.
(Front side)
Hexagonal
screwdriver
Radial
adjustment
screw
Tangential
adjustment
screw
(Rear side)
Fig. 16
23
CR200
Out of adjustment
4.2.8 Grating Re-adjustment
Optimum adjustment
Out of
adjustment
Optimum
adjustment
Fig. 17
Out of adjustment
Out of
adjustment
Adjust in the same manner as "4.2.4 Coarse Grating Adjustment ".
4.3 Adjustment 2
4.3.1 CD-R VCO Control Voltage Adjustment
• ObjectiveTo optimize the CD-R VCO control voltage adjustment of VCO IC.
• Symptom when out of adjustmentThe unit does not record or playback CD-R discs.