JVC UX-H30 User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED No.MB024
2003/8
MICRO COMPONENT SYSTEM
MB02420038UX-H30
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
MICRO COMPONENT SYSTEM
Area Suffix
U ---------------- Other Areas
UP ---------------------- Korea
UT --------------------- Taiwan
UW ---- Brazil,Mexico,Peru

1-2 (No.MB024)
SPECIFICATION
Amplifier Output Power 20 W (10 W + 10 W) at 4 Ω(10% THD)
Audio input sensitivity/Impedance (at 1 kHz) AUX 500 mV/48.75 kΩ
Speakers/Impedance 4 Ω
Tuner FM tuning range 87.50 MHz - 108.00 MHz
AM tuning range AM 10 kHz intervals 530 kHz - 1 710 kHz
AM 9 kHz intervals 531 kHz - 1 710 kHz
CD player Dynamic range 85 dB
Signal-to-noise ratio 90 dB
Wow and flutter Immeasurable
Cassette deck Frequency response Normal (type I) 50 Hz - 15 000 Hz
Wow and flutter 0.15% (WRMS)
Speaker Speaker units Full range 8.0 cm cone ×1
Impedance 4 Ω
Dimensions (approx.) 135 mm ×203 mm ×190 mm (W/H/D)
Mass (approx.) 1.7 kg each
General Power requirement AC IN 110 V/ 127 V/ 230 V ,
adjustable with the voltageselector,
50 Hz/ 60 Hz
DC IN 12 V, 4 A
Power consumption 35 W (at operation)
3.0 W (on standby)
Dimensions (approx.) 412 mm ×208 mm ×275 mm (W/H/D)
Mass (approx.) 6.5 kg

(No.MB024)1-3
SECTION 1
PRECAUTION
1.1 Safety Precautions
(1) This design of this product contains special hardware and
many circuits and components specially for safety purpos-
es. For continued protection, no changes should be made
to the original design unless authorized in writing by the
manufacturer. Replacement parts must be identical to
those used in the original circuits. Services should be per-
formed by qualified personnel only.
(2) Alterations of the design or circuitry of the product should
not be made. Any design alterations of the product should
not be made. Any design alterations or additions will void
the manufacturers warranty and will further relieve the
manufacture of responsibility for personal injury or property
damage resulting therefrom.
(3) Many electrical and mechanical parts in the products have
special safety-related characteristics. These characteris-
tics are often not evident from visual inspection nor can the
protection afforded by them necessarily be obtained by us-
ing replacement components rated for higher voltage, watt-
age, etc. Replacement parts which have these special
safety characteristics are identified in the Parts List of Ser-
vice Manual. Electrical components having such features
are identified by shading on the schematics and by ( ) on
the Parts List in the Service Manual. The use of a substitute
replacement which does not have the same safety charac-
teristics as the recommended replacement parts shown in
the Parts List of Service Manual may create shock, fire, or
other hazards.
(4) The leads in the products are routed and dressed with ties,
clamps, tubings, barriers and the like to be separated from
live parts, high temperature parts, moving parts and/or
sharp edges for the prevention of electric shock and fire
hazard. When service is required, the original lead routing
and dress should be observed, and it should be confirmed
that they have been returned to normal, after reassem-
bling.
(5) Leakage shock hazard testing
After reassembling the product, always perform an isola-
tion check on the exposed metal parts of the product (an-
tenna terminals, knobs, metal cabinet, screw heads,
headphone jack, control shafts, etc.) to be sure the product
is safe to operate without danger of electrical shock.Do not
use a line isolation transformer during this check.
• Plug the AC line cord directly into the AC outlet. Using a
"Leakage Current Tester", measure the leakage current
from each exposed metal parts of the cabinet, particular-
ly any exposed metal part having a return path to the
chassis, to a known good earth ground. Any leakage cur-
rent must not exceed 0.5mA AC (r.m.s.).
• Alternate check method
Plug the AC line cord directly into the AC outlet. Use an
AC voltmeter having, 1,000Ωper volt or more sensitivity
in the following manner. Connect a 1,500Ω10W resistor
paralleled by a 0.15µF AC-type capacitor between an ex-
posed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC
voltmeter.
Move the resistor connection to each exposed metal
part, particularly any exposed metal part having a return
path to the chassis, and measure the AC voltage across
the resistor. Now, reverse the plug in the AC outlet and
repeat each measurement. Voltage measured any must
not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5
mA AC (r.m.s.).
1.2 Warning
(1) This equipment has been designed and manufactured to
meet international safety standards.
(2) It is the legal responsibility of the repairer to ensure that
these safety standards are maintained.
(3) Repairs must be made in accordance with the relevant
safety standards.
(4) It is essential that safety critical components are replaced
by approved parts.
(5) If mains voltage selector is provided, check setting for local
voltage.
1.3 Caution
Burrs formed during molding may be left over on some parts
of the chassis.
Therefore, pay attention to such burrs in the case of pre-
forming repair of this system.
1.4 Critical parts for safety
In regard with component parts appearing on the silk-screen
printed side (parts side) of the PWB diagrams, the parts that are
printed over with black such as the resistor ( ), diode ( )
and ICP ( ) or identified by the " " mark nearby are critical
for safety. When replacing them, be sure to use the parts of the
same type and rating as specified by the manufacturer.
(This regulation dose not Except the J and C version)
Good earth ground
Place this
probe on
each expose
d
metal part.
AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
1500 10W
0.15 F AC TYPE

1-4 (No.MB024)
1.5 Preventing static electricity
Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser
diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.
1.5.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as CD players.
Be careful to use proper grounding in the area where repairs are being performed.
(1) Ground the workbench
Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the
traverse unit (optical pickup) on it.
(2) Ground yourself
Use an anti-static wrist strap to release any static electricity built up in your body.
(3) Handling the optical pickup
• In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical
pickup are shorted. After replacement, return the shorted parts to their original condition.
(Refer to the text.)
• Do not use a tester to check the condition of the laser diode in the optical pickup. The tester's internal power source can easily
destroy the laser diode.
1.6 Handling the traverse unit (optical pickup)
(1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.
(2) Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the
replacement procedure in the text. Remove the anti-static pin when replacing the traverse unit. Be careful not to take too long
a time when attaching it to the connector.
(3) Handle the flexible cable carefully as it may break when subjected to strong force.
(4) I t is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.
1.7 Attention when traverse unit is decomposed
*Please refer to "Disassembly method" in the text for the CD pickup unit.
• Apply solder to the short land sections before the flexible wire is disconnected from the connector CN601 on the CD servo board.
(If the flexible wire is disconnected without applying solder, the CD pickup may be destroyed by static electricity.)
• In the assembly, be sure to remove solder from the short land sections after connecting the flexible wire.
1M
Conductive material
(conductive sheet) or iron palate
(caption)
Anti-static wrist strap
CN601 on
mechanism
board
Shorting round
Shorting round
Flexible wire

(No.MB024)1-5
1.8 Important for laser products
1.CLASS 1 LASER PRODUCT
2.DANGER : Invisible laser radiation when open and inter
lock failed or defeated. Avoid direct exposure to beam.
3.CAUTION : There are no serviceable parts inside the
Laser Unit. Do not disassemble the Laser Unit. Replace
the complete Laser Unit if it malfunctions.
4.CAUTION : The compact disc player uses invisible laser
radiation and is equipped with safety switches which
prevent emission of radiation when the drawer is open and
the safety interlocks have failed or are de
feated. It is dangerous to defeat the safety switches.
5.CAUTION : If safety switches malfunction, the laser is able
to function.
6.CAUTION : Use of controls, adjustments or performance of
procedures other than those specified herein may result in
hazardous radiation exposure.
REPRODUCTION AND POSITION OF LABEL and PRINT
WARNING LABEL and PRINT
!Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.
Caution label

1-6 (No.MB024)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MB024)1-7
SECTION 3
DISASSEMBLY
3.1 Main body
3.1.1 Removing the rear panel
(See Fig.1,2)
(1) From behind the body, remove the nine screws Aattach-
ing the rear panel.
(2) Turing the body upside down, remove the two screws Bat-
taching the rear panel, and remove.
3.1.2 Removning the side panel (L) and (R)
(See Fig.2~5)
• Prior to performing the following procedure, remove the rear
panel.
(1) Turning the body upside down, remove the two screws C
attaching the front panel assembly.
(2) Turning the body initial position, open the CD door while
pressing the upper OPEN button.
(3) Moving the side panel (L) in the arrow direction, remove the
panel from the left side of the body.
(4) Moving the side panel (R) in the arrow direction, remove
the panel from the right side of the body.
Fig.1
Fig.2
Fig.3
Fig.4
Fig.5
A
A
A
A
BB
CC
Front panel assembly
Rear panel
Side panel (L)
Side panel (R)

1-8 (No.MB024)
3.1.3 Removing the CD player assembly
(See Fig.6,7)
• Prior to performing the following procedure, remove the rear
panel and the left and right side panels.
(1) Disconnect the card wires from the two connectors CN603
and CN604 on the CD servo control board.
(2) Remove the two screws Dattaching the front panel as-
sembly on the both sides.
(3) Release the two joints aon the both sides of the front pan-
el assembly.
(4) Move the CD player assembly in the direction of the arrow.
Fig.6
Fig.7
CD player assembly CD servo control board
CN604
D
aCN603
D
CD player assembly
a

(No.MB024)1-9
3.1.4 Removing the power amplifier board and heat sink
(See Fig.8~10)
• Prior to performing the following procedure, remove the rear
panel, the left and right side panels, and the CD player assem-
bly.
(1) Remove the five screws Eand Fattaching the heat sink.
(2) Disconnect the wire from connector CN901 on the power
supply board.
(3) Disconnect the card wire from connector CN305 on the
power amplifier board.
(4) Remove the screw Gattaching the power amplifier board.
(5) Disconnect the connector CN301 on the power amplifier
board, and release the two joints b.
REFERENCE:
Remove the screw F, then power amplifier board can be re-
moved without removing heat sink.
Fig.8
Fig.9
Fig.10
3.1.5 Removing the tuner board
(See Fig.11)
• Prior to performing the following procedure, remove the rear
panel, the left and right side panels, and the CD player assem-
bly.
(1) Remove the screw Hattaching the tuner board from the
right side of the body.
(2) Disconnect the card wire from the connector CN1 on the
tuner board.
(3) Release the joint c, and remove the tuner board backward.
Fig.11
E
E
F
Heat sink
Power amplifier board
CN301
Power supply board
CN901
CN305
Power amplifier board
G
bb
H
Tuner board
CN1
c

1-10 (No.MB024)
3.1.6 Removing the front panel assembly
(See Fig.12,13)
• Prior to performing the following procedure, remove the rear
panel the left and right side panels, the CD player assembly,
the power amplifier board.
(1) Disconnect the card wire from the connector CN714 on the
LCD system CPU board.
(2) Release the joint don the bottom of the front panel as-
sembly using a screwdriver, and remove the front panel as-
sembly toward the front.
Fig.12
Fig.13
3.1.7 Remove the power transformer and power supply board
(See Fig.14,15)
• Prior to performing the following procedure, remove the rear
panel, the left and right side panels, the CD player assembly,
the power amplifier board and the tuner board.
(1) Remove the screw Iattaching the jack holder and release
joint e, and then remove jack holder.
(2) Remove the four screws Jattaching the power transformer
and power supply board.
Fig.14
Fig.15
LCD system CPU board
CN714
dFront panel assembly
I
Jack holder
e
J
J
Power transformer
Power supply board

(No.MB024)1-11
3.1.8 Remove the cassette mechanism assembly
(See Fig.16,17)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Disconnect the card wire from the connector CN713 on the
LCD system CPU board.
(2) Remove the four screws Kand Lattaching the cassette
mechanism assembly, and remove.
Fig.16
Fig.17
Front panel assembly
LCD system CPU board
CN713
KL
Cassette mechanism assembly

1-12 (No.MB024)
3.1.9 Remove the LCD system CPU board
(See Fig.18)
(1) Disconnect the wire from the connector CN716 on the LCD
system CPU board.
(2) Release the two joints fand pull out the LCD system CPU
board.
Fig.18
3.1.10 Removing the operating switch board
(See Fig.19,20)
• Prior to performing the following procedure, remove the front
panel assembly, the cassette mechanism assembly and the
LCD system CPU board.
(1) Remove the two screws Mattaching the operating switch
button.
(2) Remove the two screws Nattaching the operating switch
board, and remove.
Fig.19
Fig.20
f
LCD system CPU board
CN716
MOperating switch button
N
Operating switch board

(No.MB024)1-13
3.2 Cassette mechanism assembly
3.2.1 Removing the Play/Record & Clear head
(See Fig.1~3)
(1) While moving the trigger arm on the right side of the head
mount in the direction of the arrow, turn the flywheel R
counterclockwise until the head mount comes ahead and
clicks.
(2) The head turns counterclockwise as you turn the flywheel
R counterclockwise (See Fig.2 and 3).
(3) Disconnect the flexible wire from connector CN31 on the
head amplifier & mechanism control board.
(4) Remove the spring from the back of the head.
(5) Loosen the azimuth screw for reversing attaching the head.
(6) Remove the head on the front side of the head mount.
Fig.1
Fig.2
Fig.3
Cassette mechanism assembly Fly wheelR
Trigger armHead mount
Head
Fly wheel R
Azimuth screw
for reversing
Flexible wire
Spring
CN31
Head amplifer & mecha control board
Head

1-14 (No.MB024)
3.2.2 Removing the head amplifier & mechanism control board
(See Fig.4)
(1) Turn over the cassette mechanism assembly and remove
the three screws Aattaching the head amplifier & mecha-
nism control board.
(2) Disconnect the flexible wire from connector CN31 on the
head amplifier & mechanism control board.
(3) Disconnect connector CN32 of the head amplifier & mech-
anism control board from connector CN1 on the reel pulse
board.REFERENCE: If necessary, unsolder the 4-pin wire
soldered to the main motor.
3.2.3 Removing the main motor
(See Fig.4~7)
(1) Remove the two screws B.
(2) Half raise the motor and remove the capstan belt from the
motor pulley.
ATTENTION:
Be careful to keep the capstan belt from grease. When reas-
sembling, refer to Fig.6 and 7 for attaching the capstan belt.
Fig.4
Fig.5
Fig.6
Fig.7
Head amplifier & mecha control board
AA
AB
CN31
CN32
4pin wire
Flexible wire
Main motor assembly
Main motor assembly
Capstan belt
Main motor assembly
Capstan belt
Motor pulley
Main motor assembly
Capstan belt
Fly wheel
Motor pulley

(No.MB024)1-15
3.2.4 Removing the flywheel
(See Fig.8, 9)
• Prior to performing the following procedure, remove the head
amplifier & mechanism control board and the main motor as-
sembly.
(1) From the front side of the cassette mechanism, remove the
slit washers attaching the capstan shaft Land R. Pull out
the flywheels backward.
Fig.8
Fig.9
3.2.5 Removing the reel pulse board and solenoid
(See Fig.10)
• Prior to performing the following procedure, remove the head amplifier & mechanism control board.
(1) Remove the screw C.
(2) Release the tab a, b, c, dand eretaining the reel pulse board.
(3) Release the tab fand gattaching the solenoid on the reel pulse board.
(4) The reel pulse board and the solenoid come off.
Fig.10
Fly wheel R Fly wheel L
Capstan shaft R Capstan shaft L
Fly wheel R
Slit washer
Fly wheel L
a
fg
bc d
e
C
Reel pulse board
Solenoid

1-16 (No.MB024)
3.2.6 Reattaching the Play/ Record & Clear head
(See Fig.11~13)
(1) Reattaching the head mount assembly.
a) Change front of the direction cover of the head
mount assembly to the left (Turn the head forward).
b) Fit the bosses O', P', Q', U' and V' on the head mount
assembly to the holes Pand V, the slots O, Uand Q
of the mechanism sub assembly (See Fig.11 to 13).
CAUTION:
To remove the head mount assembly, turn the direction
cover to the left to disengage the gear. If the gear can not
be disengaged easily, push up the boss Q' slightly and
raise the rear side of the head mounts slightly to return
the direction lever to the reversing side.
(2) Tighten the azimuth screw for reversing.
(3) Reattach the spring from the back of the Play/ Record &
Clear head.
(4) Connect the flexible wire to connector CN31 on the head
amplifier & mechanism control board. Fig.11
Fig.12
Fig.13
P'
V'
O'
P'
V'
U' Q'
Direction cove
r
Head mount assembly
Direction cove
r
Head mount assembly
O
U
V
PQ
Azimuth screw for reversing
Head mount
Spring
Flexible wire
Head amplifier &
mechanism control board
CN31
Head

(No.MB024)1-17
SECTION 4
ADJUSTMENT
4.1 Measurement Instruments Required for Adjustment
(1) Low frequency oscillator
This oscillator should have a capacity to output 0dBs to
600Ωat an oscillation frequency of 50Hz-20kHz.
(2) Attenuator impedance : 600Ω
(3) Electronic voltmeter
(4) Distortion meter
(5) Frequency counter
(6) Wow & flutter meter
(7) Test tape
VT703L : Head azimuth
VT712 : Tape speed and running unevenness (3kHz)
VT724 : Reference level (1kHz)
(8) Blank tape
TYPE l : AC-225
TYPE ll : AC-514
(9) Torque gauge : For play and back tension
FWD(TW2111A), REV(TW2121a) and FF/REW(TW2231A)
(10) Test disc: CTS-1000
4.2 Measurement conditons
4.2.1 Radio Input signal
4.2.2 Tuner section
4.2.3 Standard measurement position of volume
Precautions for measurement
(1) Apply 30pF and 33kΩto the IF sweeper output side and
0.082µF and 100kΩin series to the sweeper input side.
(2) The IF sweeper output level should be made as low as
possible within the adjustable range.
(3) Since the IF sweeper is a fixed device, there is no need
to adjust this sweeper.
(4) Since a ceramic oscillator is used, there is no need to
perform any MIX adjustment.
(5) Since a fixed coil is used, there is no need to adjust the
FM tracking.
(6) The input and output earth systems are separated. In
case of simultaneously measuring the voltage in both of
the input and output systems with an electronic voltmeter
for two channels, therefore, the earth should be connect-
ed particularly carefully.
(7) In the case of BTL connection amp., the minus terminal
of speaker is not for earthing. Therefore, be sure not to
connect any other earth terminal to this terminal. This
system is of an BTL system.
(8) For connecting a dummy resistor when measuring the
output, use the wire with a greater code size.
(9) Whenever any mixed tape is used, use the band pass fil-
ter (DV-12).
Power supply voltage AC 110V/127V/230V
adjustable with the voltage selector,
50Hz/60Hz
Reference output Speaker : 0.775V/4Ω
Headphone : 0.077V/32Ω
Reference frequency and input level 1kHz, AUX : -8dBs
Measurement output terminal at Speaker J3002
Load resistance 4Ω
AM frequency 400Hz
AM modulation 30%
FM frequency 400Hz
FM frequency deviation 22.5kHz
Voltage applied to tuner +B : DC5.7V
VT : DC 12V
Reference measurement output 26.1mV(0.28V)/3Ω
Input positions AM : Standard loop antenna
FM : TP1 (hot) and TP2 (GND)
Function switch to Tape
Beat cut switch to Cut
Super Bass/Active hyper Bass to OFF
Bass Treble to Center
Adjustment of main volume to reference output VOL : 0.775V

1-18 (No.MB024)
4.3 Cassette mechanism adjustment
M
otor speed
V
R37
BIAS adjust
VR31
Mecha control board
Head azinuth
adjustment screw
(Forward side)
Head azinuth
adjustment screw
(Reverse side)
Head azinuth
adjustment screw
(Forward side)
Head azinuth
adjustment scre
w
(Reverse side)
R/P head, Erase head
CN31
D1
FW100
R371
VR37
P1
SW1
SW6
CN1
SW2
SW5
IC1
C201
C102
C103
C105
C106
C107
C209
C110
C113
C121
C101
C202
C203
C205
C206
C207
C109
C210
C213
C221
C300
C301
C304
C306
C307
C308
C310
C313
C314
C316
C319
C331
C340
C341
C342
C371
C374
C376
CN31
CN33
CN34
D340
D375
IC32
IC33
L301
L303
Q302
Q305
Q342
Q343
Q344
Q345
Q346
Q371
Q372
Q375
Q376
R101
R102
R104
R105
R106
R107
R108
R110
R116
R121
R201
R202
R204
R205
R206
R207
R208
R210
R216
R221
R301
R302
R303
R304
R305
R306
R310
R313
R314
R315
R327
R335
R336
R337
R338
R339
R340
R341
R342
R343
R344
R345
R346
R353
R372
R375
R376
VR31
CN32
C204
C104 R109
Q347
R347
W1
W1

(No.MB024)1-19
4.3.1 Mechanism section
Item Condition Measurement method Ref. value Adjustment
position
Head azimuth Test tape
:VT703L (8kHz)
Output terminal
:Speaker out
(1) Playback the test tape VT703L (8kHz).
(2) Adjust to maximum output level by azi-
muth adjustment screw for forward side
and reverse side.
(3) This adjustment is adjust by adjustment
screw of forward side and adjustment
screw of reverse side.
Maximum output Only adjust
at changed
head
Tape speed Test tap
:VT712 (3kHz)
Output terminal
:Speaker out or Headphone out
Playback the test tape VT712 (3kHz) at end of
forward side,adjust to 2,940~3,90Hz indication
of frequency counter by VR37.
2,940 ~ 3,090Hz VR37
Item Condition Measurement method Ref. value Adjustment
position
Tape speed
diviation at FWD/
REV
Test tape
: VT712 (3kHz)
Output terminal
:Speaker out or Headphone out
Playback the test tape VT712 (3kHz) at end of
forward and reverse, tape speed deviation
should be less than 6.0Hz.
Leass than
6.0Hz VR31
Wow & Flutter Test tape
: VT712 (3kHz)
Output terminal
:Speaker out or Headphone out
Playback the test tape VT712 (3kHz) at start of
forward and reverse, Wow & Flutter are should
be less than 0.25%(WRMS).
Lessthan0.25%
(WRMS)

1-20 (No.MB024)
4.3.2 Electrical adjustment
4.3.3 Electrical response confirmation
Item Condition Measurement method Ref. value Adjustment
position
Recording BIAS
adjustment • Forward or Reverse • Test tape
: AC-514 TYPE ll
: AC-225 TYPE l
• Output termina
Recording head
(1) Set the test tape(AC-514 TYPE ll and
AC-225 TYPE l), then make REC/
PAUSE condition.
(2) Connect 100Ωto recording head by se-
ries, then connect to VTVM for measure-
ment the current.
(3) After setting, start the recording by re-
lease the PAUSE, in this time bias cur-
rent adjust to next fig. by VR31 for Lch
and VR32 for Rch.
4.0 µA (TYPE ll) and 4.20 µA (TYPE l).
AC-225
: 4.20µA
AC-514
: 4.0µA
VR31
R/P playback
frequency
response
• Reference frequency
: 1kHz / 10kHz
(Reference: -20dB)
• Test tape
: AC-514 TYPE ll
• Input terminal
: OSC IN
(1) Set the test tape (AC-514 TYPE ), then
make REC/PAUSE condition.
(2) ReleasethePAUSE,thenstartrecording
the 1kHz and 10kHz of reference fre-
quency from oscillator.
(3) Playback the recorded position, 1kHz
and 10kHz output deviation should -1dB
2dB to readjust by VR31 for Lch and
VR32 for Rch.
Output deviation
1kHz/10kHz
: -1dB ± 2dB
VR31
Item Condition Measurement method Ref. value Adjustment
position
Recording bias
current • Forward or Reverse • Test tape
: TYPE ll (AC-514)
• Measurement terminal
: BIAS test point on printed
circuit board
(1) Change BIAS1 and 2, confirm the fre-
quency should be change.
(2) Set the test tape (AC-514 TYPE ll), then
make REC/PAUSE condition.
(3) Confirm the frequency should 100Hz ±
6kHz at BIAS test point on printed circuit
board.
100 kHz ± 6 kHz
Erase current (ref-
erence value) • Forward or Reverse • Rec condition
Test tape
: AC-514 TYPE ll
: AC-225 TYPE l
• Measurement terminal
Both side of Erase head
(1) Set the test tape (AC-514 TYPE ll and
AC-225 TYPE l), then make REC/
PAUSE condition.
(2) Release the PAUSE to REC condition,
connect 1W to ERASE head by series,
then confirm the erase current at both
side of erase head.
TYPE ll
: 120 mA
TYPE l
: 75 mA