HCD-GRX9000/RX900 are the Amplifier,
CD player, Tape Deck and Tuner section
in MHC-GRX9000/RX900.
Dolby noise reduction manufactured under license
from Dolby Laboratories Licensing Corporation.
“DOLBY” and the double-D symbol a are trademarks of Dolby Laboratories Licensing Corporation.
Photo: HCD-RX900
CD
Section
TAPE
DECK
Section
East European Model
CIS Model
HCD-RX900
E Model
HCD-GRX9000
Model Name Using Similar MechanismHCD-H991AV
CD Mechanism TypeCDM38LH-5BD29AL
Base Unit TypeBU-5BD29AL
Optical Pick-up TypeKSS-213D/Q-NP
Model Name Using Similar Mechanism HCD-GRX7/RX77S
7-33. IC Pin Function Description ........................................... 81
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic break-down because of the potential difference generated
by the charged electrostatic load, etc. on clothing and the human
body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused
on the disc reflective surface by the objective lens in the optical
pick-up block. Therefore, when checking the laser diode emission, observe from more than 30 cm away from the objectiv e lens.
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be damaged by heat.
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270 ˚C during repairing.
• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
• Be careful not to apply force on the conductor when soldering
or unsoldering.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation exposure.
This appliance is classified as a CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT MARKING is located on
the rear exterior.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
The following caution label is located inside the unit.
9.ELECTRICAL PARTS LIST ............................... 95
– 3 –
MODEL IDENTIFICATION
– Back Panel –
PART N o.
MODELPART No.
E model4-996-846-0π
Malaysia, Singapore models4-996-846-1π
Saudi Arabia model4-996-846-2π
East European, CIS models4-996-846-5π
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED
LINE WITH MARK ! ON THE SCHEMATIC DIA GRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
– 4 –
HOW TO OPEN THE DISC TRAY WHEN POWER SWITCH TURNS OFF.
e
1
Remove the Case.
3
Pull-out the disc tray.
2
Turn the cam to the
direction of arrow.
NOTE FOR INSTALLATION (ROTARY ENCODER)
BU cam
Section A
Groove
Note:When attaching the BU cam,
engage the Rotary encoder
switch as shown in the figure.
Note:When attaching the Base unit, Insert th
section A into the groove of BU cam.
– 5 –
LOCATION OF CONTROLS
SECTION 2
GENERAL
!∞
!§
!¶
!•
!ª
@º
@¡
@™
@£
1234
5
6
7
8
9
!º
!¡
!™
!£
!¢
1 I /u (Power) button
2 DISC 1 to 3 buttons and indicators
3 DISC SKIP/EX-CHANGE button
4 6 (CD) button
5 CD disc tray
6 CD ^ button and indicator
7 TUNER, BAND button
8 r REC button and indicator
9 P PAUSE button and indicator
!º HI-DUB button
!¡ CD SYNC button
!™ EFFECT button and indicator
!£ SURROUND button
!¢ KARAOKE PON/MPX button
!∞ TAPE B 9 and ( buttons and indicators
!§ TAPE A 9 and ( buttons and indicators
!¶ FUNCTION button
!• MIC LEVEL knob
!ª MIX MIC jac
@º DISPLAY/DEMO button
@¡ CLOCK/TIMER SET button
@™ TIMER SELECT button
@£ p button
#∞
#§
#º
#¡
#™
#£
#¢
#¶
#•
#ª
@¢
$º$¡$™$£ $¢ $∞$§
@∞
@§
@¶
@•
@ª
@¢ Fluorescent indicator tube
@∞ ENTER/NEXT button and indicator
@§ GROOVE button and indicator
@¶ VOLUME konb
@• PHONES jack
@ª DBFB button
#º Remote sensor
#¡ P FILE MEMORY button
#™ GEQ CONTROL button
#£ FILE SELECT button
#¢ LOOP button
#∞ NON-STOP button and indicator
#§ FLASH button
#¶ EDIT, DIRECTION button
#• PLAY MODE, DOLBY NR button
#ª REPEAT button
$º § button (deck A)
$¡ Tape deck A
$™ –, 0 button and indicator
$£ JOG dial
$¢ +, ) button and indicator
$∞ Tape deck B
$§ § button (deck B)
– 6 –
– 7 –
SECTION 3
)
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
• The cold reset clears all data including preset data stored in the
RAM to initial conditions. Execute this mode when returning
the set to the customer.
Procedure:
1. Press three buttons p , [ENTER/NEXT], and I/u simulta-
neously.
2. The fluorescent indicator tube becomes blank instantaneously ,
and the set is reset.
[CD Delivery Mode]
• This mode moves the pickup to the position durable to vibration. Use this mode when returning the set to the customer after
repair.
Procedure:
1. Press I/u button to turn the set ON.
2. Press [LOOP] button and I/u button simultaneously.
3. A message “LOCK” is displayed on the fluorescent indicator
tube, and the CD delivery mode is set.
[MC Hot Reset]
• This mode resets the set with the preset data kept stored in the
memory. The hot reset mode functions same as if the power
cord is plugged in and out.
Procedure:
1. Press three buttons p , [ENTER/NEXT], and [DISC1] si-
multaneously.
2. The fluorescent indicator tube becomes blank instantaneously ,
and the set is reset.
[Sled Servo Mode]
• This mode can run the CD sled motor freely. Use this mode, for
instance, when cleaning the pickup.
Procedure:
1. Press
2. Select the function “CD”.
3. Press three buttons p , [ENTER/NEXT], and § simulta-
4. The Sled Servo mode is selected, if “CD” is blanking on the
5. With the CD in stop status, press ) + button to move the
6. To exit from this mode, perform as follows:
Note: • Always move the pickup to most inside track when exiting from
I/u button to turn the set ON.
neously.
fluorescent indicator tube.
pickup to outside track, or – 0 button to inside track.
1)Move the pickup to the most inside track.
2)Press three buttons in the same manner as step 3.
this mode. Otherwise, a disc will not be unloaded.
• Do not run the sled motor excessively , otherwise the gear can be
chipped.
[Change-over of AM Tuner Step between 9 kHz and
10 kHz]
• A step of AM channels can be changed ov er between 9 kHz and
10 kHz.
Procedure:
1. Press I/u button to turn the set ON.
2. Select the function “TUNER”, and press [TUNER/BAND]
button to select the BAND “AM”.
3. Press I/u button to turn the set OFF.
4. Press [ENTER/NEXT] and I/u buttons simultaneously, and
the display of fluorescent indicator tube changes to “AM 9 k
STEP” or “AM 10 k STEP”, and thus the channel step is
changed over.
[Change-over of LW Tuner Step between 1 kHz and
3 kHz]
• A step of L W channels can be changed ov er between 1 kHz and
3 kHz.
Procedure:
1. Press I/u button to turn the set ON.
2. Select the function “TUNER”, and press [TUNER/BAND]
button to select the BAND “LW”.
3. Press I/u button to turn the set OFF.
4. Press [ENTER/NEXT] and I/u buttons simultaneously, and
the display of fluorescent indicator tube changes to “LW 1 k
STEP” or “LW 3 k STEP”, and thus the channel step is changed
over.
[LED and Fluorescent Indicator Tube All Lit, Key Check
Mode]
Procedure:
1. Press three buttons p , [ENTER/NEXT], and [DISC2] si-
multaneously.
2. LEDs and fluorescent indicator tube are all turned on.
Press [DISC2] button, and the key check mode is activated.
3. In the key check mode, the fluorescent indicator tube displays
“K 1 J0 V0”. Each time a button is pressed, “K” value increases. However , once a button is pressed , it is no longer taken
into account.
“J” value increases like 1, 2, 3 ... if rotating [JOG] knob in “+”
direction, or it decreases like 0, 9, 8 ... if rotating in “–” direction.
“V” value increases like 1, 2, 3 ... if rotating [VOLUME] knob
in “+” direction, or it decreases like 0, 9, 8 ... if rotating in
“–” direction.
4. To exit from this mode, press three buttons in the same man-
ner as step 1, or disconnect the power cord.
[Change-over of FUNCTION Name]
• The FUNCTION name of external input terminal can be changed
over to “VIDEO” of “MD”.
Procedure:
1. Press I/u button to turn the set OFF.
2. Press I/u button together with [FUNCTION] button, and the
power is turned on, the display of fluorescent indicator tube
changes to “MD” of “VIDEO” instantaneously, and thus the
FUNCTION is changed over.
– 11 –
[Aging Mode]
This mode can be used for operation check of CD section and tape
deck section.
• If an error occurred:
The aging operation stops and display status.
• If no error occurs:
The aging operation continues repeatedly.
1. Operating Method of Aging Mode
1) Set disc in DISC1 tray.
2) Load the tapes recording use into the decks A and B respec-
tively.
3) Press three buttons p , [ENTER/NEXT],
and [DISCSKIP/EX-CHANGE] simultaneously.
4) The aging mode is activated, if a CD roulette mark on the fluo-
rescent indicator tube is blinking.
5) To exit from the aging mode, press I/u button to turn the set
OFF.
2. Operation Sequence
• During the aging mode in the following sequence to below.
• Starting the CD section aging for function set “CD”, starting
the TAPE section (deck A) aging for function set “TAPE A” or
“TAPE B”. (Set another function is no work.)
CD (disc1) (12 minutes) → Deck A
↑↓(Maximum about
Deck B12 minutes)
3. Aging mode in CD section
1) Display state
• No error occurs
display
1 –
[*][*]
Note:
: a letter “CD” and the remainder time (minute) alternately. (re-
[*][*]
mainder time start from 12 minute)
@@: track number in access.
@ @
• Error occurred
NO.DisplayMain factor
1 NO DISC ERR Not set disc in DISC1
2 FOCUS1 ERR Focus does not work
3 FOCUS2 ERR Focus does not work after the disc rotate as usual
4 GFS ERRGFS error
5 FBIAS ERRError in to the focus bias adjustment
6 SENSOR ERR Disc sensor sens DISC1 is no disc
7 TABLE ERRCD tray lotate does not work
8 TRAY ERRTray (include BD) move does not work
4. Aging mode in Tape Deck section
1) Display state
• No error occurs
Display action now
• Error occurred
Display action last time
NO. Display actionAction contentsFinal timing
1TAPE A AG-1 Rewind the TAPE AThe top of tape
2TAPE A AG-2 FWD play the TAPE A 2 minutes playing
3TAPE A AG-3 F.F. the TAPE AFirst either 20 seconds
or the end of tape
4TAPE A AG-4 REV play the TAPE A2 minutes playing
5TAPE A AG-5 Rewind the TAPE AThe top of tape
6TAPE B AG-1 Rewind the TAPE BThe top of tape
7TAPE B AG-2 FWD play the TAPE B 2 minutes playing
8TAPE B AG-3 F.F. the TAPE BFirst either 20 seconds
or the end of tape
9TAPE B AG-4 REV play the TAPE B 2 minutes playing
10 TAPE B AG-5 Rewind the TAPE BThe top of tape
2) Operation during Aging Mode
In the aging mode, the program is executed in the following sequence.
(1) The tape in deck A is rewound to the head.
(2) The FWD side is played back for 2 minutes.
(3) The tape is fast forwarded (FF) for 20 seconds. The follow-
ing procedure is performed when the tape end is reached
before the 20 seconds.
(4) The REV side is played back for 2 minutes.
(5) The tape is rewound to the head (REW).
(6) The tape in deck B is rewound to the head.
(7) The FWD side is played back for 2 minutes.
(8) The tape is fast forwarded (FF) for 20 seconds. The follow-
ing procedure is performed when the tape end is reached
before the 20 seconds.
(9) The REV side is played back for 2 minutes.
(10) The tape is rewound to the head (REW).
(11) Aging is switched to the CD player.
2) Operation during aging Mode
In the aging mode, the program is executed in the following sequence.
(1) The CD tray rotates and disc 1 is selected.
(2) Chucking is performed.
(3) TOC is read.
(4) Track 1 played back for 8 seconds.
(5) The CD tray opens and closes again.
(6) 1 to 5 is repeated.
(7) After 12 minutes of aging, aging is switched to the tape deck.
– 12 –
SECTION 5
MECHANICAL ADJUSTMENTS
SECTION 6
ELECTRICAL ADJUSTMENTS
Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
2. Demagnetize the record/playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
Torque Measurement
ModeTorque meterMeter reading
FWDCQ-102C
FWD
back tension(0.03 – 0.08 oz • inch)
REVCQ-102RC
REV
back tension(0.03 – 0.08 oz • inch)
FF/REWCQ-201B
FWD tensionCQ-403A
REV tensionCQ-403R
CQ-102C
CQ-102RC
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
71 to 143 g • cm
(0.99 – 1.99 oz • inch)
100 g or more
(3.53 oz or more)
100 g or more
(3.53 oz or more)
DECK SECTION0 dB=0.775 V
1. Demagnetize the record/playback head with a head demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjust.
4. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in
this service manual. (As a general rule, playback circuit adjustment should be completed before performing recording
circuit adjustment.)
6. The adjustments should be performed for both L-CH and RCH.
7. Switches and controls should be set as follows unless otherwise specified.
• Test Tape
TapeSignalUsed for
P-4-A10010 kHz, –10 dBAzimuth Adjustment
WS-48B3 kHz, 0 dBTape Speed Adjustment
P-4-L300315 Hz, 0 dBLevel Adjustment
Record/Playback Head Azimuth Adjustment
DECK A DECK B
Note: Perform this adjustments for both decks
Procedure:
1. Mode: Playback (FWD)
test tape
P-4-A100
(10 kHz, –10 dB)
set
MAIN board
CN301
3
(L-CH)
Pin
Pin
1
(R-CH)
MAIN board
CN301
Pin
2
(GND)
level meter
+
–
– 13 –
2. Turn the adjustment screw and check output peaks. If the peaks
(
)
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
Output
level
within
1dB
L-CH
peak
R-CH
peak
within
1dB
Screw
position
L-CH
peak
Screw
position
R-CH
peak
3. Mode: Playback (FWD)
Tape Speed Adjustment DECK B
Note: Start the Tape Speed adjustment as below after setting to the test
mode.
In the test mode, the tape speed is high during pressing the
[HI-DUB] button.
Procedure:
1. Turn the power switch on.
2. Press the p button, [ENTER/NEXT] button and [DISC3] b utton
simultaneously.
(The “VOLUME” on the fluorescent indicator tube will blink
while in the test mode.)
To exit from the test mode, press the I/u button.
Mode: Playback
test tape
WS-48B
(3 kHz, 0 dB)
set
frequency counter
+
–
test tape
P-4-A100
(10 kHz, –10 dB)
in phase 45 °90 °135 °180
MAIN board
CN301
(pin
3
: L-CH)
(pin
good
(pin 2: GND)
1
: R-CH)
wrong
set
waveform of oscilloscope
oscilloscope
H
V
°
4. Repeat setps 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location:Playback Head (Deck A).
Record/Playback/Erase Head (Deck B).
MAIN board
CN301 (Pin
3
: L-CH)
Pin 1 : R-CH
1. Insert the WS-48B into the deck B.
2. Press the · button on the deck B.
3. Press the [HI-DUB] button in playback mode.
Then at HIGH speed mode.
4. Adjust RV1001 on the LEAF SW board do that frequency
counter reads 6,000 ± 180 Hz.
5. Press the [HI-DUB] button.
Then back to NORMAL speed mode.
6. Adjust RV1002 on the LEAF SW board so that frequency
counter reads 3,000 ± 90 Hz.
Adjustment Location: LEAF SW board
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
Playback level Adjustment DECK ADECK B
Procedure:
Mode: Playback
test tape
P-4-L300
(315 Hz, 0 dB)
set
level meter
+
–
forward
reverse
MAIN board
CN301 (Pin
(Pin
3
1
: L-CH)
: R-CH)
Deck A is RV311 (L-CH) and RV411 (R-CH), Deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
Adjustment Level:
CN301 PB level: 301.5 to 338.3 mV (–8.2 to –7.2 dB) level
difference between the channels: within ± 0.5 dB
Adjustment Location: AUDIO board
– 14 –
REC Bias Adjustment DECK B
set
MD/VIDEO (AUDIO) IN
315 Hz, 50 mV (–23.8 dB)
blank tape
CS-123
600
Ω
attenuator
AF OSC
+
–
++
–
–
+
–
set
recorded
portion
MAIN board
CN301 (Pin
3
: L-CH)
(Pin
1
: R-CH)
level meter
REC LEVEL
13
RV301
L
RV351
R
CN106
CN301
CN107
RV401
RV301
RV341
RV311
RV411
IC602
CN601
LR
RL
RV441
PB LEVEL
– DECK B –
REC BIAS
LR
PB LEVEL
– DECK A –
Procedure:
INTRODUCTION
When set to the test mode performed in T ape Speed Adjustment,
when the tape is rewound after recording, the “REC memory mode”
which rewinds only the recorded portion and playback is set.
This “REC memory mode” is convenient for performing this adjustment. During recording, the input signal FUNCTION will automatically switch to VIDEO.
(After recording, press the – 0 button without stopping will
return to the position where recording was started.)
1. Press [FUNCTION] button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press [REC] button, press P button, then recording
r
start.
4. Mode: Record
4. Mode: Record
5. Mode: Playback
AF OSC
+
–
MD/VIDEO (AUDIO) IN
1) 315 Hz
2) 10 kHz
attenuator
+
–
50 mV (–23.8 dB)
600
Ω
+
–
set
blank tape
CN-123
5. Mode: Playback
recorded
portion
set
MAIN board
CN301 (Pin
(Pin
level meter
+
–
3
: L-CH)
1
: R-CH)
6. Confirm playback the signal recorded in step 3 become adjustable level as follows.
If these levels do not adjustable level, adjustment the RV341
(L-CH) and RV441 (R-CH) on the AUDIO board to repeat
steps 4 and 5.
Adjustable level: Playback output of 315 Hz to playback output
of 10 kHz: ± 1.0 dB
Adjustment Location: AUDIO board
6. Confirm playback the signal recorded in step 3 become adjustable level as follows.
If these levels do not adjustable level, adjustment the RV301
(L-CH) and R V351 (R-CH) on the MAIN board to repeat steps
4 and 5.
Adjustable level:
CN301 PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
Adjustment Location:
[MAIN BOARD] (Component Side)
REC Level Adjustment DECK B
Procedure:
INTRODUCTION
When set to the test mode performed in T ape Speed Adjustment,
when the tape is rewound after recording, the “REC memory mode”
which rewinds only the recorded portion and playback is set.
This “REC memory mode” is convenient for performing this adjustment. During recording, the input signal FUNCTION will automatically switch to VIDEO.
(After recording, press the – 0 button without stopping will
return to the position where recording was started.)
1. Press [FUNCTION] button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press [REC] button, press P button, then recording
start.
r
[AUDIO BOARD] (Component Side)
[LEAF SW BOARD] (Component Side)
TAPE SPEED
(NORMAL) (HIGH)
RV1002
RV1001
– 15 –
CN1001
TUNER SECTION0 dB=1 µV
l
(East European, CIS models only)
Note: As a front-end (FE1) is difficult to repair if faulty, replace it with
new one.
MW Section Adjustment
Note: FM Tuned Level Adjustment should be performed after this MW
Tuned Level Adjustment.
Setting:
loop antenna
AM RF SSG
30% amplitude
modulation by
400 Hz signal
Field strength dB (
60 cm
MW Tuned Level Adjustment
Band: MW
Procedure:
1. Set the output of SSG so that the input level of the set becomes 55 dB.
2. Tune the set to 1,050 kHz.
3. Adjust R V41 to the point (moment) when the TUNED indicator will change from going off to going on.
Adjustment Location : TCB board
loop antenna
(Supplied accessories)
µ
V/m) =SSG output level dB (µV/m) –26 dB.
set
MW ANTENNA
terminal (TM1)
FM Section Adjustment
Note: This adjustment should be performed after the MW Tuned Level
1. Set the modulation of FM RF SSG to AUDIO 1 kHz, 10 kHz
deviation according to “Connection 1”.
2. Tune the set to 69 MHz.
3. Adjust the RV1702 so that the reading of frequency counter
connected to TP1702 becomes within 31.25 kHz ± 0.05 kHz.
(VCO Adjustment)
4. Then record the reading of the level meter connected to TP1701
5. Set the modulation of FM RF SSG to AUDIO 31.25 kHz, 10
kHz deviation according to “Connection 2”.
6. Tune the set to 69 MHz.
7. Set the CT1701 to be mechanical center.
8. Adjust the L1701 so that the reading of the level meter connected to TP1701 become maximum.
Then adjust the CT1701 so that the reading of the level meter
connected to TP1701 becomes maximum. (SUB CARRIER
PEAK Adjustment)
9. Adjust the RV1701 so that the level at the moment becomes
14dB higher value than the level recorded in step 4. (SUB CARRIER LEVEL Adjustment)
set
Adjustment Location :
[TCB BOARD] (Component Side)
TM1
IFT41
IC41
CN1
RV41
MW T uned Level
Adjustment
RV42
FM T uned Level
Adjustment
L1701
Sub Carrier Pea
Adjustment
RV1701
Sub Carrier Level
Adjustment
CT1701
Sub Carrier Peak
Adjustment
RV1702
VCO Adjustment
[TCB BOARD] (Conductor Side)
– 17 –
CD SECTION
V
+
–
BD board
TP (TEO)
TP (VC)
oscilloscope
)
Note:
1. CD Block is basically designed to operate without adjustment. Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
2. Connect between test point TP (FOK) and GND by lead wire.
3. Turn Power switch on.
4. Put disc (YEDS-18) in and turned Power switch on again and
actuate the focus search. (Actuate the focus search when disc
table is moving in and out.)
5. Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 3±1
Vp-p.
S-curve waveform
symmetry
A
B
within 3
±
1 Vp-p
6. After check, remove the lead wire connected in step 2.
Note: • T ry to measure se v eral times to make sure than the ratio of A : B
or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the brightness
to obtain best waveform.
RF Level Check
oscilloscope
BD board
TP (RF)
TP (VC)
+
–
Procedure:
1. Connect oscilloscope to test point TP (RF) on BD board.
2. Turned Power switch on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF signal level is correct or not.
Note: Clear RF signal waveform means that the shape “≈” can be clearly
distinguished at the center of the waveform.
Procedure:
1. Connect oscilloscope to test point TP (TEO) on BD board.
2. Turned Power switch on. Press [FUNCTION] button to select
CD.
3. Put disc (YEDS-18) in to play the number five track.
4. Press the p button, [ENTER/NEXT] button and ^ button simultaneously several times to fluorescent indicator tube
display “SHUFFLE” is blink. (The sledding servo is turned
OFF.)
5. Check the level B of the oscilloscope’s waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following:
A
× 100 = less than ±7 (%)
B
Traverse waveform
0 V
level: 500
±
100 mVp-p
Center of the waveform
B
A (DC
voltage)
symmetry
6. Press the p button, [ENTER/NEXT] button and ^ button
simultaneously several times to fluorescent indicator tube display “SHUFFLE” is OFF. (The sleding servo is turned ON.)
Confirm the C (DC voltage) is almost equal to the A (DC v oltage) is step 5.