Sharp MD-MT80W(S) User manual

MD-MT80W/90W/90/90C
Page
SAFETY PRECAUTION FOR SERVICE MANUAL (MD-MT80W/90W ONLY) ..................................................................... 2
AC ADAPTOR AND PLUG (MD-MT80W/90W ONLY) .......................................................................................................... 3
SPECIFICATIONS ................................................................................................................................................................. 4
ACCESSORIES ..................................................................................................................................................................... 6
NAMES OF PARTS ............................................................................................................................................................... 7
OPERATION MANUAL .......................................................................................................................................................... 8
QUICK GUIDE (MD-MT90 ONLY) ....................................................................................................................................... 12
DISASSEMBLY.................................................................................................................................................................... 14
REMOVING AND REINSTALLING THE MAIN PARTS....................................................................................................... 15
ADJUSTMENT ...................................................................................................................................................................... 16
MD ERROR MESSAGE DISPLAY CONTENT LIST ........................................................................................................... 29
NOTES ON SCHEMATIC DIAGRAM .................................................................................................................................. 30
TYPES OF TRANSISTOR AND DIODE .............................................................................................................................. 30
BLOCK DIAGRAM ............................................................................................................................................................... 31
SCHEMATIC DIAGRAM ...................................................................................................................................................... 32
WIRING SIDE OF P.W.BOARD........................................................................................................................................... 34
WAVEFORMS OF MD CIRCUIT ......................................................................................................................................... 37
VOLTAGE ............................................................................................................................................................................ 38
TROUBLESHOOTING ......................................................................................................................................................... 39
FUNCTION TABLE OF IC.................................................................................................................................................... 42
PARTS GUIDE/EXPLODED VIEW
PACKING OF THE SET (FOR U.S.A. ONLY)
MD-MT80W(S)
MD-MT90W(S)
MD-MT90(S)
MODEL MD-MT90C(S)
CONTENTS
SERVICE MANUAL
SHARP CORPORATION
No. S4123MDMT80W/
This document has been published to be used
for after sales service only.
The contents are subject to change without notice.
• In the interests of user-safety the set should be restored to its
original condition and only parts identical to those specified be
used.
PORTABLE MINIDISC RECORDER
Illustration: MD-MT80W
Illustration: MD-MT90W/90/90C

– 2 –
MD-MT80W/90W/90/90C
Precaution to be taken when replacing and servicing the laser pickup.
The following precautions must be observed during servicing to protect your eyes against exposure to the laser.
Warning of possible eye damage when repairing:
If the AC adaptor or batteries are connected when the top housing (disc cover) of the unit is removed, and the PLAY key is
pressed, the laser will light up during focus access (2-3 seconds). (Fig. 2-1) During the operation, the laser will leak from the
opening between the magnetic head and the mechanical chassis (Fig. 2-2). In order to protect your eyes, you must not look
at the laser during repair. Before repairing be sure to disconnect the AC adaptor and remove the batteries.
Precaution to be taken when replacing and servicing the
Laser Pickup.
THEAEL(ACCESSIBLEEMISSIONLEVEL)OFTHELASER
POWEROUTPUTISLESSTHANCLASS1BUTTHELASER
COMPONENT IS CAPABLE OF EMITTING RADIATION
EXCEEDING THE LIMIT FOR CLASS 1. THEREFORE IT IS
IMPORTANTTHATTHEFOLLOWINGPRECAUTIONSARE
OBSERVED DURING SERVICING TO PROTECT YOUR
EYES AGAINST EXPOSURE TO THE LASER BEAM.
(1) When the cabinet has been removed, the power is
turnedon withouta compactdisc, andthe Pickupis on
apositionouter thanthelead-inposition, theLaserwill
light for several seconds to detect a disc. Do not look
into the Pickup Lens.
(2) The Laser Power Output of the Pickup inside the unit
and replacement service parts have already been
adjusted prior to shipping.
(3) NoadjustmenttotheLaserPowershouldbeattempted
when replacing or servicing the Pickup.
(4) Under no circumstances look directly into the Pickup
Lens at any time.
(5) CAUTION - Use of controls or adjustments, or
performance ofproceduresother thanthosespecified
herein may result in hazardous radiation exposure.
SAFETY PRECAUTION FOR SERVICE MANUAL
Laser Diode Properties
●Material: GaAlAs
●Wavelength: 785 nm
●Pulse time:
Read mode: 0.8 mW Continuous
Write mode: max 10 mW 0.5S
min cycle 1.5S
Repetition
Magnet head
Optical pickup Top Cabinet
,,,
Laser Beam
Optical Pick-Up
Main PWB
Spindle motor
Mechanism
Chassis Magnet Head
Figure 2-1 Figure 2-2
English:
This product is classified as a CLASS 1 LASER PRODUCT.
German:
Dieses Produkt ist ein Laserprodukt der Klasse 1.
French:
Ce Produit est Classifié comme étant un PRODUCTO
LASER DE CLASSE 1.
(MD-MT80W/90W ONLY)

– 3 –
MD-MT80W/90W/90/90C
AC ADAPTOR AND PLUG
(MD-MT80W/90W ONLY)
PADPA6049AWZZ PADPA5052AWZZ PADPA5051AWZZ PADPA5050AWZZ
QPLGA0004AWZZ

– 4 –
MD-MT80W/90W/90/90C
FORACOMPLETEDESCRIPTIONOFTHEOPERATIONOFTHISUNIT,PLEASEREFERTO
THE OPERATION MANUAL.
Specifications for this model are subject to change without prior
notice
SPECIFICATIONS
MD-MT80W/90W
■General
Power source:
Battery life:
●The continuous recording time is for analogue inputs
when the volume level is set to "VOL 0".
●The continuous play time shows the value when the
volume level is set to "VOL 15".
●The above values are the standard values when the
unit is charged and used at an ambient temperature of
25°C (77°F).
●The operating time when using an alkaline battery
may be different, depending on the type and manufac-
turer of the battery, and on the operating temperature.
DC 5V: AC adaptor (AC 110-240V, 50/60 Hz)
DC 1.5V: Commercially available, "AA" size
(LR6), alkaline battery x 1
DC 1.2V: Optional rechargeable Nickel-Metal
Hydride battery (AD-N70BT) x 1
DC 4.5V: Optional car adaptor, AD-CA20X(for
cars with a 12 - 24V DC negative earth
electrical system)
Power con-
sumption: 0.15 A (AC adaptor)
Output pow-
er: RMS; 20 mW (10 mW + 10 mW)
(0.2% T.H.D.)
Charging
time: Approx. 3.5 hours (90 %)
Approx. 5.5 hours (fully charged)
(When using the AC adaptor included
with the unit)
When using the optional
rechargeable battery (fully
charged)
When using a commercial-
ly available, high capacity,
"AA" size (LR6), alkaline
battery
Continuous recording:
Approx. 7 hours Continuous recording: Approx. 3 hours
Continuous play:
Approx. 12 hours Continuous play: Approx. 12 hours
Input sensitivity:
Output level:
■MiniDisc Recorder
Recording
level Reference input level Input impedance
MIC H 0.25 mV 10 k ohms
MIC L 2.5 mV 10 k ohms
LINE 100 mV 20 k ohms
Specified
output Maximum output level Load im- pedance
Headphones - 10 mW + 10
mW 16 ohms
LINE 250mV (-12
dB) - 10 k ohms
Dimensions: Width: 81.1 mm (3-7/32")
Height: 19.9 mm (13/16")
Depth: 92.4 mm (3-21/32")
Weight: 147 g (0.32 lbs.) without battery
(MD-MT80W)
172 g (0.38 lbs.) with rechargeable battery
(MD-MT90W)
Input socket: Line/optical digital, microphone (pow-
ered by the main unit)
Output sock-
et: Headphones (impedance: 16 ohms)
Type: Portable MiniDisc recorder
Signal read-
out: Non-contact, 3-beam semi-conductor
laser pick-up
Audio chan-
nels: Stereo2channels/monaural(long-play
mode) 1 channel
Frequency
response: 20 - 20,000 Hz (±3 dB)
Rotation
speed: Approx. 400 - 900 rpm
Error correc-
tion: ACIRC (Advanced Cross Interleave
Reed-Solomon Code)
Coding: ATRAC(AdaptiveTRansformAcoustic
Coding), 24-bit computed type
Recording
method: Magnetic modulation overwrite method
Sampling fre-
quency: 44.1 kHz (32 kHz and 48 kHz signals
are converted to 44.1 kHz, and then re-
corded.)
Wow and
flutter: Unmeasurable (less than ±0.001%W.
peak)

– 5 –
MD-MT80W/90W/90/90C
MD-MT90/90C
■General
Power source:
Battery life:
●The continuous recording time is for analog inputs
when the volume level is set to "VOL 0".
●The continuous play time shows the value when the
volume level is set to "VOL 15".
●The above values are the standard values when the
unit is charged and used at an ambient temperature of
77°F (25°C).
●The operating time when using an alkaline battery
may be different, depending on the type and manufac-
turer of the battery, and on the operating temperature.
DC 1.2V: Rechargeable Nickel-Metal Hydride
battery (AD-N70BT) x 1
DC 5V: AC adaptor (AC 120V, 60 Hz)
DC 1.5V: Commercially available, "AA" size
(LR6), alkaline battery x 1
DC 4.5V: Optional car adaptor, AD-CA20X(for
cars with a 12 - 24V DC negative
ground electrical system)
Power con-
sumption: 7 W (AC adaptor)
Output pow-
er: RMS; 20 mW (10 mW + 10 mW)
(0.2% T.H.D.)
Charging
time: Approx. 3.5 hours (90 %)
Approx. 5.5 hours (fully charged)
(When using the AC adaptor included
with the unit)
When using the recharge-
ablebattery(fullycharged)
included with the unit
When using a commercial-
ly available, high capacity,
"AA" size (LR6), alkaline
battery
Continuous recording:
Approx. 7 hours Continuous recording: Approx. 3 hours
Continuous play:
Approx. 12 hours Continuous play: Approx. 12 hours
Input sensitivity:
Output level:
■MiniDisc Recorder
Recording
level Reference input level Input impedance
MIC H 0.25 mV 10 k ohms
MIC L 2.5 mV 10 k ohms
LINE 100 mV 20 k ohms
Specified
output Maximum output level Load im- pedance
Headphones - 10 mW + 10
mW 16 ohms
LINE 250 mV
(-12 dB) - 10 k ohms
Dimensions: Width: 3-7/32" (81.1 mm)
Height: 13/16" (19.9 mm)
Depth: 3-21/32" (92.4 mm)
Weight: 0.38 lbs. (172 g) with rechargeable bat-
tery
Input jack: Line/optical digital, microphone (pow-
ered by the main unit)
Output jack: Headphones (impedance: 16 ohms)/
remote control unit
Type: Portable MiniDisc recorder
Signal read-
out: Non-contact, 3-beam semiconductor
laser pickup
Audio chan-
nels: Stereo2channels/monaural(long-play
mode) 1 channel
Frequency
response: 20 - 20,000 Hz (±3 dB)
Rotation
speed: Approx. 400 - 900 rpm
Error correc-
tion: ACIRC (Advanced Cross Interleave
Reed-Solomon Code)
Coding: ATRAC(AdaptiveTRansformAcoustic
Coding), 24-bit computed type
Recording
method: Magnetic modulation overwrite method
Sampling fre-
quency: 44.1 kHz (32 kHz and 48 kHz signals
are converted to 44.1 kHz, and then re-
corded.)
Wow and
flutter: Unmeasurable (less than ±0.001%W.
peak)

– 6 –
MD-MT80W/90W/90/90C
ACCESSORIES
MD-MT80W
MD-MT90/90C
Notes:
●Parts and equipment mentioned in this operation manual other than those detailed above are not included.
●The AC adaptor may be different from the one in the drawing.
Headphones x 1
AC Adaptor x 1
or
or
or
Connection Cable (for analogue
recording) x 1
Notes:
●Parts and equipment mentioned in this operation manual other than those detailed above are not included.
●The AC adaptor may be different from the one in the drawing.
Remote Control x 1
(RRMCW0002AWSA) Headphones x 1 (RPHOH0005AWZZ) AC Adaptor (RADPA3048AWZZ) x 1 Battery Carrying Case x 1 (UBAGC0003AWZZ)
Rechargeable Nickel-
Metal Hydride Battery
(AD-N70BT) x 1
(UBATM0003AWSA)
Connection Cable (for
analog recording) x 1
(QCNWG0029AWZZ)
Connection Cable (for
digital recording) x 1
(QCNWG0422AFZZ)
Carrying Bag x 1
(UBAGC0006AWSA)
MD-MT90W
Notes:
●Parts and equipment mentioned in this operation manual other than those detailed above are not included.
●The AC adaptor may be different from the one in the drawing.
Remote Control x 1
Headphones x 1 Battery Carrying Case x 1
Rechargeable Nickel-Metal
Hydride Battery (AD-N70BT) x 1
Connection Cable (for
digital recording) x 1
Connection Cable (for analogue
recording) x 1
MD-MT90W
AC Adaptor x 1
or
or or

– 7 –
MD-MT80W/90W/90/90C
NAMES OF PARTS
■Main unit
1.5V DC Input Jack
2.Optical/Line Input Jack
3.Microphone Input Jack
4.Bass/Delete Button
5.Edit/Auto Mark/Time Mark Button
6.Display/Character Select Button
7.Mode/Charge Button
8.Record/Track Mark Button
9.Volume/Cursor/Fast Forward/Fast Reverse/
Recording Level/Name Select Button
10.Play/Pause Button
11.Stop/Power Off/Hold Button
12.Enter/Fast Play/Synchro Button
13.Remote Control/Headphones/Line Output Jack
14.Open Lever
15.Battery Cover
Illustration: MD-MT90W/90/90C
Illustration: MD-MT80W
■Main unit
1.5V DC Input Socket
2.Optical/Line Input Socket
3.Microphone Input Socket
4.Bass/Delete Button
5.Edit/Auto Mark/Time Mark Button
6.Display/Character Select Button
7.Mode/Charge Button
8.Record/Track Mark Button
9.Volume/Cursor/Fast Forward/Fast Reverse/
Recording Level/Name Select Button
10.Play/Pause Button
11.Stop/Power Off/Hold Button
12.Enter/Fast Play/Synchro Button
13.Headphones/Line Output Socket
14.Open Lever
15.Battery Cover

– 8 –
MD-MT80W/90W/90/90C
OPERATION MANUAL
Battery Power
■Charging the rechargeable battery
When a separately available rechargeable battery is
used for the first time or when you use it after a long
period of disuse, be sure to charge it fully.
●After the rechargeable battery is charged or used, it
will get slightly warm. This is normal.
●When the portable MD is turned on or operating, the
battery will not be charged.
1
2
1
Insert the rechargeable battery.
A rechargeable battery other than the AD-N70BT
cannot be
2
Plug the AC adaptor into the wall socket, and
then insert the plug on the other end into the DC
IN 5V socket.
3
Press the MODE/CHRG button.
" " will flash, and battery will begin charging.
charged.
Illustration: MD-MT90W
MD-MT80W/90W
■Display panel
1.Level Meter
2.Record Indicator
3.Remaining Recording Time Indicator
4.Monaural Long-Play Mode Indicator
5.Repeat Indicator
6.TOC Indicator
7.Synchro Recording Indicator
8.Disc Mode Indicator
9.Disc Name Indicator
10.Track Name Indicator
11.Total Track Number Indicator
12.Fast Play Indicator
13.Battery Indicator
14.Random Indicator
15.Track Number Indicator
16.Character/Time Information Indicator
■Remote control unit (MD-MT90W/90/90C)
1.Headphones Jack
2.Bass/Delete/Track Mark Button
3.Volume Down/Cursor Button
4.Volume Up/Cursor Button
5.Hold Switch
6.Play/Pause Button
7.Fast Reverse/Recording Level Down/Name Select
Button
8.Fast Forward/Recording Level Up/Name Select
Button
9.Stop/Power Off Button
NAMES OF PARTS

– 9 –
MD-MT80W/90W/90/90C
MD-MT90/90C
■Checking the remaining amount of bat-
tery level
The remaining amount of battery level is shown by the
battery indicator ( ) during operation.
●When the battery is completely discharged, the bat-
tery indicator will flash. Recharge the battery or
replace the alkaline battery with a new one.
●When the battery has run completely out, "BATT
EMPTY" will appear. Then, the power will be discon-
nected automatically.
Notes:
●If you use the battery which you stopped charging
halfway, " " may appear. It does not mean that the
battery is completely charged.
●The battery indicator will not correctly display the
remaining capacity for approximately 10 seconds after
the power has been turned on.
●When the AC adaptor or a separately available car
adaptor is used, the battery indicator will not be
shown.
●The number of bars shown in the battery indicator may
increase or decrease, depending on the operation
being performed. This is normal.
■Using with the rechargeable or alkaline
battery
Notes:
●Setting the volume level to "0" whilst recording with the
rechargeable or an alkaline battery reduces the bat-
tery drain.
●When you do not use the unit for hours, remove the
battery. (The battery drains gradually even when the
power is turned off.)
●This unit can be used with the AC adaptor when the
●Carry the battery in the supplied case.
(Except for MD-MT80W)
rechargeable or an alkaline battery is in the unit.
Caution:
Do not use a nickel-cadmium battery.
1
Disconnect the AC adaptor.
2
Insert the rechargeable bat-
tery or alkaline battery from
the (+) marked side.
Use a commercially available LR6,
"AA" size alkaline battery.
Battery Power
■Charging the rechargeable battery
When the rechargeable battery is used for the first time
or when you want to use it after a long period of disuse,
be sure to charge it fully.
●After the rechargeable battery is charged or used, it
will get slightly warm. This is normal.
●When the portable MD is turned on or operating, the
battery will not be charged.
1
Insert the rechargeable battery.
A rechargeable battery other than the one supplied
or the optional one (AD-N70BT) cannot be charged.
2
Plug the AC adaptor into the AC outlet, and
then insert the plug on the other end into
the DC IN 5V jack.
3
Press the MODE/CHRG button.
" " will flash, and battery will begin charging.
MD-MT80W/90W/90/90C

– 10 –
MD-MT80W/90W/90/90C
Error Messages
ERROR MESSAGES MEANING REMEDY
BATT EMPTY ●The battery is run down. ●Charge the rechargeable battery or replace the al-
kaline battery (or use the AC adaptor for power).
BLANK MD ●Nothing is recorded. ●Replace the disc with a recorded disc.
Can't COPY ●You tried to record from a copy prohibited
MiniDisc. ●Record using the analog cable.
Can't EDIT ●A track cannot be edited. ●Change the stop position of the track and thenedit it.
Can't READ (*) ●The disc data cannot be read because the
disc or unit is damaged. ●Reload the disc.
●Replace it with another recorded disc.
Can't REC ●Recording cannot be performed correctly
due to vibration or shock. ●Re-record or replace it with another recordable
disc.
Can't STAMP ●Stamp function does not work. ●Check the number of tracks.
Can't WRITE ●Cannot save the TOC information correctly
to a MiniDisc. (A large portion ofthe disc has
been damaged.)
●Replace the disc with another recordable disc.
DEFECT ●The disc is scratched. ●If the sound you hear is not right, record again.
●Replace the disc with another recordable disc.
DISC FULL ●The disc is out of recording space. ●Replace it with another recordable disc.
Er-MD (**) ●The microprocessor has reported a system
fault and the unit is out of order. ●To have it repaired,go to the distributor where you
purchased the unit.
HOLD ●The unit is in the hold mode. ●Cancel the hold mode.
LOCKED ●You removed a MiniDisc while recording or
editing. ●Turn off the power and remove the MiniDisc.
NO DISC ●A disc has not been loaded. ●Load a disc.
Number or symbol appears in (*) position. (Refer to P.29)
NO SIGNAL ●Poor connection of the digital cable. ●Connect the digital cable securely.
●No output signal comes out from the
connected unit to playback. ●IftheportableCDplayerhasafunctiontopreventsound
skips, deactivate it.
●Theinputsignalhasimpropersampling
frequency. ●Playback with the connected unit.
NOT PLAY ●You tried to play back a track that can-
not be played with this equipment. ●Play back another track.
PLAY MD ●You recorded on a playback-only disc. ●Replace it with a recordable disc.
POWER ? ●Improper power is being supplied. ●Use one of the specified power sources.
PROTECTED ●The write protection tab of aMiniDiscis
set to the protected position. ●Move the write protection tab back to its original posi-
tion.
●
Youtried to recordon aplayback-onlydisc.
●Replace it with a recordable MiniDisc.
SORRY ●Since a track number iscurrently being
located or updated, the unit cannot ac-
cept your command.
●Wait for a while and try the operation again.
TEMP OVER ●The temperature is too high. ●Turn off the power, and wait for a while.
TOC FORM (**) ●There is an error in the recording signal. ●Erase all of the tracks, and then record again.
TOC FULL ●There is no space left for recording
character information (track names,
disc names, etc.).
●Replace it with another recordable disc.
Tr. Protect ●The track has been protected from be-
ing erased. ●Edit the track with the device on which it was recorded.
? DISC ●A disc which contains data other than
music was played. ●A disc which contains non-music data cannot beplayed.
●There is anerror in thesignal recorded
on the disc. ●Replace it with another recorded disc.
Number or symbol appears in (*) position. (Refer to P.29)