Sony WM-DDIII User manual

WM-Dul
SERVICE MANUAL
HEADPHONES jacks (stereo minijacks)-
REW ► ► (rewind) button'
<*4 FF (fast forward) button
<4 PLAY button
■ STOP button
Dolby noise reduction manufactured under license from
Dolby Laboratories Licensing Corporation.
"DOLBY” and the double-D symbol □□ are trademarks of
Dolby Laboratories Licensing Corporation.
Refer t MDR-15L Service Manual issued previously
for informati n of headphones supplied with this set.
AEP Model
VOLUME control
BATTERY indicator
DOLBY NR switch
-TAPE selector
PHOTO: BLACK TYPE
SPECIFICATIONS
Similar Mechanism Set
WM-DD
Tape Transport Mechanism Type
DD-tOO
Tape track
4-track 2-channel stereo
Fast winding time
Approx. 2 min. with Sony Cassette C-60
Frequency response
40-15,000 Hz
Wow and flutter
±0.13% (DIN)
0.08% WRMS (NAB)
Power output
Headphones:
20mW + 20mW {at 10% harmonic distortion)
load impedance 32 ohms
at DC operation
Outputs
Two HEADPHONES jacks (stereo minijacks)
load impedance 8-300 ohms
Power requirements
3 V DC, two R6 (size AA) batteries
DC IN 3 V jack accepts:
EBP-500 battery case (optional) for use on
two R20 (size D) batteries
AC-D2M AC power adaptor (optional) for use
on 220 V AC, 50 Hz
DCC-70 or DCC-127A car battery cord (optional) for use with 12 V
car battery
(For connection with the DCC-127A, the optional PC-200 DC plug
adaptor is required.)
Battery life
Batteries
Continuous playback hours
Sony batteries SUM-3 (NS)
Approx. 4
Sony alkaline batteries AM3
Approx. 9
For maximum performance we recommend the use of alkaline
batteries.
Dimensions
Approx. 79.7x110x32.8mm (w/h/d)
(3V 4 x 4 %x 1 s / 16 inches)
incl. projecting parts and controls
Weight
Approx. 290 g (10.3 oz) incl. batteries,
not incl. other accessories
Note: If a car battery cord or an AC power adaptor not manufactured by Sony
is used, a fuse must be installed in the battery cord or the AC power
adaptor and the polarity of the plug must be as illustrated.
FEATURES
• Disc Drive system assures accurate and stable tape trans¬
port, greatly reducing wow and flutter.
• Dolby NR system reduces tape hiss noise.
• Tape selector for optimum playback with standard tapes
as well as high-performance tapes.
• Two HEADPHONES jacks allow two persons to listen to
tape playback together.
STEREO CASSETTE PLAYER

WM-DD1
Replacing chip components
All chip components should be connected and disconnect¬
ed, using a tapered soldering iron [temperature of the iron
tip: less than 280°C (536°F)], a pair of tweezers and braid¬
ed wire.
Precautions for replacement
1. Do not disconnect the chip component forcefully.
Otherwise, the pattern may peel off.
2. Never re-use a disconnected chip component. Dispose of
all old chip components.
3. To protect the chip component, heating time for attach¬
ing the component should be within 3 seconds.
o Removing chip components
(1) R emoving solder at electrode
Remove the solder at the electrode, using a thin
braided wire. Do not remove the solder of the part
(chip component) attached adjacent to the electrode.
(2) D i sconnecting chip components
Turn the tweezers with the soldering iron alternately
applied to both electrodes, and the chip component
will be disconnected. Take careful precautions while
disconnecting, because if the chip component is force¬
fully removed the land may peel off.
Never re-use a disconnected chip component.
(3) S moothing the soldered surface
After disconnecting the chip component, remove the
solder by using a braided wire to smooth the land
surface.
o Connecting chip components
The value of chip components is not displayed on the
main body. Take due precautions to avoid mixing new
chip components with other ones.
(1) A pplying solder to land on one side
Apply a thin layer of solder to the land on one side
where the chip component is to be connected. Too
much solder may cause bridging.
Small quart tity of solder
(2) S peedy soldering
Hold the chip component at the desired position,
using tweezers, and apply the soldering iron in the
arrow-marked direction. To protect the chip compo¬
nent, heating time should be within 3 seconds.
(3) S p eedy soldering of electrode on the other side
Solder the electrode on the other side in the same
way as in (2) above.
- 2 -

SECTION 1
MECHANICAL OPELATION
MECHANICAL OPERATION in this set is the same
as that of model WM-DD, so refer to WM-DD service
manual previously issued for MECHANICAL OPERA¬
TION.
SECTION 2
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
WM-DDIK WM-DDI
Cassette Panel
Q Remove cassette panel.
Main B ard
Motor
precision screw
P 1.4 x 1.8l TYPE 3
- 3 -
- 4 -

WM-DDH
PRECAUTION
SECTION 3
ADJUSTMENTS
1. Clean the following parts with a denatured-
alcohol-moistened swab:
playback head pinch roller
capstan
2. Demagnetize the 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.
3-1. MECHANICAL ADJUSTMENT
Torque Measurement
Perform with 2.5 V DC power.
Torque
meter
Meter reading
FWD
CQ-102C
22 - 46 g*cm
(0.3 - 0.63 oz*inch)
FF, REW
CQ-201B
More than 65 g»cm
(More than 9.04 oz*inch)
Back
Tension
CQ-102C
1 - 3.5 g-cm
(0.01 - 0.05 oz«inch)
Tape Pull¬
ing Force
CQ-403
More than 80g*cm
(More than 11.12 oz*inch)
Pinch Roller Pressure Adjustment
— Playback Mode —
1. P u l l the spring scale in the direction shown by
the arrow.
2. S l o w l y return the pinch roller and read the
spring scale just when the pinch roller starts
rotating. q
XoX
Specification:
170±20g (5.3 ~6.7 oz)
o
Head Height Adjustment
1. Prepare an adjustment cassette as shown below.
C-120
tape cassette
portions.
2. In playback mode and viewing from the front,
adjust the head heights to eliminate tape curl
and tape twist at portions shown by the arrow.
playback head
n
r m
3-578-138-01 (t= 0.1)
3-578-138-11 ft = 0.2)
Sh im, head h eigh t ad jus tmen t
3. I f necessary, adjust the height of the tape-guide
by turning the adjustment screw.
adjustment screw
4. A p p l y locking compound on adjustment screw.
5

WM-DDH
1. Motor section installation
2. Wow & flutter and motor position
1. Adjust with the adjustment screw so that rotor
thrust play is within 0.1mm. (When confirming
play, press motor down so that the motor
pulley and rotor rubber section do not touch.)
2. Wow & flutter adjustment
Setting:
Power supply voltage: 2.5V
Tape: Adjust by using end portion of tape.
VOLUME control: mechanical mid
TAPE SELECT switch: NORM
DOLBY NR switch: OFF
Procedure:
0 Mode: playback
test tape wow & flutter
WS-48A meter
(3kh
iz, OdB)
32SI
- 1 — 1
L^J
set
J 1_
-o
-°
Vj
\
HEADPHONES
Turn the adjustment screw so that the wow
and flutter meter reads minimum (less than
0.12% W-RMS).
( 2 ) At 2V power supply voltage, confirm normal
FWD operation.
Q) When ® and Q) are not satisfied, repeat adjust¬
ment again starting with “Motor Section
Installation”.
Press down
6

WM
2-2. ELECTRICAL ADJUSTMENTS
Tape Speed Adjustment
Setting:
VOLUME control: mechanical mid
TAPE SELECT switch: NORM
DOLBY NR switch: OFF
Procedure:
Mode: playback
test tape
WS-48A
(3 kHz, OdB)
digital frequency
counter
\J HEADPHONES
1. Open the solder bridge shown below.
2. Turn RV601 so that frequency reading be¬
comes in 3090 Hz ± 10 Hz. (at the ending part
of the test tape)
3. Resolder the adjustment patterns opened in
step 2 above. Now frequency reading should be¬
comes in 3000 Hz ± 9 Hz.
Specification:
Digital frequency counter
3000 Hz ± 9 Hz
Adjustment Location:
— main board —
Adjustment
patterns
I O 1 ^ tc>rO
X60I M
mm lu
UL—C-— i—
7 1 T
Playback Head Azimuth Adjustment
Setting:
VOLUME control: mechanical mid
TAPE SELECT switch: NORM
DOLBY NR switch: OFF
Procedure:
1. M o d e : playback
test tape
P-4-A WO u
UD/
32n
LJ
L_ I 1—
set 1 i % |
— —K _Lj-i
-
U HEADPHONES
2. T urn the adjustment screw for the maximum
output levels. If these levels do not match, turn
the adjustment screw until both of output
levels match together within 1 dB.
Screw
position
3. P hase Check
Mode: playback
test tape
P-4-A063
(6.3kHz, —WdB)
L-CH R‘CH
peak peak
32SI oscilloscope
HEADPHONES
Screen pattern
0 @ ®
in phase 45° 90° 13 5° 18(f
good
wrong
8

SECTION 4
DIAGRAMS
3-1. MOUNTING DIAGRAM
I I 1 1 l I 3 I .. 4 I 5 1 6
12.1*11 1 ^3 ~T _ 14
isIn- 2 ®l
[MAIN BOARD]
(SIDE A)/
17 ; ~18 1 ~ 19 T 20
~r\ r 22
Semiconductor Lead Layouts
MSM58141RS BA3304F
NJM2063AM
Jill TA7688F
K I CX20084
2SA812
2SC1623
2SB624-BV4
2SD596
2SB798
C
[MAIN BOARD]
(SIDE B}j
[MAW BOARD]
SIDE A) I ✓
[MAIN BOARD]
FG 90 [ [
FG COIL
koft ^ I Veapth j
b I
ON S302
_J_J00LB]_NR
OFF
SR506D
I
RD7.5M-B1
Semiconductor Location
Ref. N .
Descripti n
R f. No.
Description
D301
D-18 Q302
K-13
D302
J-15
Q303
0-10
D303
Q-10 Q304
P-10
D701
P-5 Q305
N-11
Q601
R-6
IC301
M-17
Q602
N-9
IC302
0-14
Q701
P-5
IC303
L-12
Q702
U-5
IC601
Q-7 Q703
Q-5
IC602
N-6
<3Hr-0
M90I
MNR- 1600A
MOTOR
4-'.- />*h
“i ^ >4
- : parts extracted from the component side.
- : parts extracted from the conductor side.
: part mounted on the conductor side.
: Through hole.
?: component-side pattern.
[RY BATTERY
i IZE "AA"
{ EC DESIGNATION R6)

WM-DDH WM-DD1
i
8 9
10
11
12
13
14
15
3-2. SCHEMATIC DIAGRAM
B
H
N te:
All capacitors are in juF unless otherwise noted. pF: ppF
50WV or less are not indicated except for electrolytics
and tantalums.
All resistors are in n and i/«W or less unless otherwise
specified.
nmi mu Mi'infr : L-CH signal path
— : R-CH signal path
11
MNR-160IA
MOTOR FG COIL
' : B+ bus.
I : adjustment for repair.
Power voltage is 3 V and fed with regulated dc power
supply from
Voltage variations may be noted due to norma! produc¬
tion tolerances.
Waveforms are taken to ground in PLAY mode by using
oscilloscope.
Voltage variations may be noted due to normal produc¬
tion tolerances.
Switches:
Ref. No.
Switch
Positi n
S301
TAPE
NORM
S302
DOLBY NR
OFF
S901
POWER
ON
Touching the pin No. 11 of IC601 with the tester probe
causes an extra vibration inside the 1C, which will be
heard from the phones as a high-pitched sound.
If the pin No. 11 of IC601 is touched with the tester
probe, the voltage there will increase, and after about 1
second it will get higher than 0.8V, so that the motor
M901 will stop.
- 1 2 -

1C BLOCK DIAGRAMS
IC301 BA3304F
IC302 NJM2063AM
1C
303 TA7688F
TIME
CONSTANT
2
feH-W-H
[-^-W-H^TiME
CONSTANT
I
WM-DDI
IC601 CX20084
IC602 MSM58141RS
6ND 4/5 SELECT
3 -

WM-DDD I
SECTION 5
EXPLODED VIEWS AND PARTS LIST
REVISED
NOTE:
•The mechanical parts with no reference
number in the exploded views are not
supplied.
•The construction parts of an assembled
part are indicated with a collation
number in the remark column.
* Color Indication of Appearance Parts
Example: (RED) . KNOB, BALANCE
t (WHITE)
t
Parts' Color
No. Part No.
Description Remarks
No. Part No.
Description Remarks
1
X-3310-950-1 (SILVER)...PANEL ASSY, CONTROL
15
3-578-232-00
(SILVER)...ORNAMENT, ADJUSTMENT HOLE
X-3310-951-1 (BLACK)....PANEL ASSY, CONTROL
3-578-232-11
(RED).ORNAMENT, ADJUSTMENT HOLE
X-3310-952-1 (RED).PANEL ASSY, CONTROL
3-578-232-21
(BLACK)....ORNAMENT, ADJUSTMENT HOLE
2 3-704-246-31
(SILVER).SCREW (PI.4X2.5)
16
X—3310—953—1
(SILVER)...PANEL ASSY, CASSETTE
3-704-246-32
(BLACK,RED)...SCREW (PI.4X2.5)
X-3310-954-1
(BLACK)....PANEL ASSY, CASSETTE
X-3310-955-1
(RED).PANEL ASSY, CASSETTE
3
3-310-947-00 SPRING, COMPRESSION
4
3-310-983-02
BUTTON, LOCK 17
3-578-101-00
PLATE, ORNAMENTAL
18
*3-701-999-00
LABEL, SERIAL NUMBER
HP* -5" 3
324 435 01
(SILVER,RED) ...LABEL, TH—not supplied—
20
3-578-236-00
SPRING (BATTERY)
.3-324-435-11
(BLACK).LABEL, D(_, not supplied-
21
3-578-115-00 LID, BATTERY CASE
6
*3-324-430-01 (SILVER).LABEL, MODEL NUMBER
22
*3-324-415-01 CUSHION
*3-324-430-11
(BLACK,RED)...LABEL, MODEL NUMBER
23
3-578-114-00 PANEL, CHASSIS
24
7-627-850-58
SCREW, PRECISION +P 1.4X3.5
7
3-307-831-00 SCREW, PANEL
25
3-324-431-01
KNOB, VOL
8
3-335-797-21 SCREW (Ml.4X3), TOOTHED LOCK
9
3-831-441-11 CUSHION (B) 26
3-310-979-01
BUTTON, SELECTION, TAPE
10
9-911-838-XX
CUSHION, METER
27
3-310-978-01
BUTTON, SELECTION, NR (DOLBY)
901
A-3216-178-A PC BOARD ASSY, MAIN
11 9-911-816-01
CLOTH, DRAWER, BATTERY
12
3-831-441-XX
SPACER
13 3-703-710-01
STICKER, SONY SYMBOL (12)
14 3-578-109-00
CONTACT
- 1 4 -