Emerson EWC1902 Schematic

Servo/System Control Block Diagram

(DECK ASSEMBLY)

AC HEAD ASSEMBLY

CL402

CONTROL
HEAD

5 5CTL(+)
6 6CTL(-)

BLOCK DIAGRAMS

MAIN CBA

Q202 Q206

SENSOR CBA
(ST-SENSOR)

Q201

END-SENS.

SENSOR CBA
(END-SENSOR)

TIMER+5V

D203
S-LED

T-REELST-SENS.

AL+5V

SW212
LD-SW

RS201

WF3

CTL

Q205

RESET

REMOTE
SENSOR

J116

AL+5V

IC201

(SERVO/SYSTEM CONTROL)

KEY 0

KEY 1

REMOTE

14

CTL AMP-OUT

97
95

CTL(+)
CTL(-)

94

LD-SW1

ST-SENS.

9
7

END-SENS.
T-REEL

80

34

RESET

P-ON-H

P-DOWN

REC LED
REC LED 22

I2C-OPEN

SP-MUTE

A-MUTE

D-REC-H

SCL

SDA

31
84

23

71

72

45

12
65
44

SW201 SW205

5

6

KEY
SWITCH

SW206 SW210

KEY
SWITCH

D204 REC

P-ON-H

P-DOWN

TO POWER
SUPPLY BLOCK

(MEMORY)

IC202

SCL

6

5

SDA

CS

7

I2C-OPEN

SP-MUTE

A-MUTE

D-REC-H

EXT-H/INSEL

SCL
SDA

SCL
SDA

AL+5V

TO CHROMA
/TUNER
BLOCK

TO AUDIO
BLOCK

CYLINDER ASSEMBLY

PG
SENSOR

DRUM
MOTOR

M

LOADING
MOTOR

M

CAPSTAN MOTOR

CAPSTAN
MOTOR

M

C-CONT

D-CONT

CN201
1C-F/R
2AL+12V
3D/L+12V
4P-ON+5V
5GND
6C-FG
7
8GND

9D-FG
10LD-CONT
11
12D-PG

AL+12V
D/L+12V
P-ON+5V

C-F/R

66

C-FG

87

C-CONT

76

D-FG

89

LD-CONT

82

D-CONT77
D-PG

90

REC-SAFETY

REC/EE/PB

C-SYNC

DV-SYNC

RF-SW

TAPE-SPEED 28

EXT-H/INSEL 29

RENTAL 30

SPL-PLAY

V-ENV

ROTA

33

27
74
13
10
15
18

32

SW211

REC
SAFETY

REC/EE/PB

C-SYNC

DV-SYNC

V-ENV

ROTA

RF-SW

TAPE-SPEED

EXT-H/INSEL

RENTAL

SPL-PLAY

TO VIDEO
BLOCK

1-8-1 1-8-2 T7300BLS

Video Block Diagram

REC VIDEO SIGNAL PB VIDEO SIGNAL MODE: SP/REC

TO CHROMA/
TUNER BLOCK

TO CHROMA/
TUNER BLOCK

JK701
REAR V-IN

FROM/TO
SERVO/SYSTEM
CONTROL BLOCK

V-OUT

VIDEO

TU-VIDEO
EXT-V-IN

EXT-H/INSEL
RENTAL
REC/EE/PB

SPL-PLAY
C-SYNC

ROTA
D-V SYNC
TAPE-SPEED

WF5

J188

IC401

VIDEO/AUDIO
SIGNAL PROCESS

WF4

TUNER

42

42

38

LINE

71
36

RENTAL
REC/EE/PB

16
73

TRICK

34

ROTA

14

D-V SYNC

39

SP/LP/EP

59

V-AGC

SYNC
SEPA

Q401

BUFFER

R

P

35

6dB

AMP

CHARA

MIX

FBC

R P

Y/C
MIX

MAIN CBA

45 47 49 44

CCD 1H

DELAY

DOC YNR Y/C COMB

CHROMINANCE

SIGNAL PROCESS

Q402

BUFFER

LUMINANCE

SIGNAL PROCESS

AGC
AMP

(DECK ASSEMBLY)

CYLINDER ASSEMBLY

VIDEO (L) HEAD

VIDEO (R) HEAD

CL401

V(L)

3

V-COM

2

V(R)

1

FROM/TO
SERVO/SYSTEM
CONTROL BLOCK

WF1

RF-SW

V-ENV

J190

RF-SW

88
89
90
91

13

93

L
R

HPF

ENV
DET

74

J189

PB-C-MONI

WF6

R

P

1-8-3 1-8-4 T7300BLV

Audio Block Diagram



FROM/TO
CHROMA/TUNER
BLOCK

FROM/TO
SERVO/SYSTEM
CONTROL BLOCK

JK702
A-IN

TU-AUDIO

SDA
SCL

WF7

BLOCK DIAGRAM FOR SECTION 2 (DECK MECHANISM)

48

26
27

53

IC301

LIMITER

SERIAL

I/F

FM DET

AF
AMP

TUNER

LINE/PB

ATT

54

51

WF8

J187

A-OUT

Q302

BUFFER

PB-AUDIO SIGNAL REC-AUDIO SIGNAL

MAIN CBA

IC801 (AMP)

7

OUTPUT

AMP

MUTE

5

IC401

(AUDIO PROCESS)

1

SP-MUTE
FROM PIN 12
OF IC201

80

Mode : SP/REC

76

TUNER

LINE

CN802
SP
SP-GND 2

JK801
EARPHONE JACK

1

SP801
SPEAKER

AC HEAD ASSEMBLY

AUDIO
HEAD

AUDIO
ERASE
HEAD

FE HEAD UNIT

FULL
ERASE
HEAD

CN287

A-PB/REC

AE-H
AE-H/FE-H

ALC

REC
AMP

LINE
AMP

D-REC-H

12

11

MUTE

71

EXT-H/INSEL TO SERVO/

D-REC-H

96

A-MUTE

SYSTEM
CONTROL
BLOCK

R

CL402
4
3A-COM
1
2

A-PB/REC

4

A-COM

3

AE-H

1

AE-H/FE-H

2

CL403

FE-H

1

FE-H GND

2

Q873

Q874

Q872
BIAS

OSC

Q871

P-ON+5V

Q875

P-ON+5V

4

99

EQ
AMP

SP/LP-ON

3

AUTO
BIAS

1
2

6

100

WF9

P

7 98

1-8-5

T7300BLA1-8-6

Chroma/Tuner Block Diagram

TU001

AGC

1

IF

11

SDA

5

SCL

4

FSC

8

INT.MONITOR

I2C-OPEN

SDA 4
SCL 5

CN303 is used for
adjustment at factory

REC-AUDIO SIGNAL

J191

RF AGC-OUT

SF001

SAW
FILTER

CN303(NO CONNECTION)
1
2

IC301 VIDEO/AUDIO/CHROMA/DEFLECTION/IF

59

63

64

43

26
27

18

WF2

31

SERIAL
I/F

INTELLIGENT
MONITORING

IF SIGNAL
CONTROL
CIRCUIT

REC VIDEO SIGNAL PB VIDEO SIGNAL Mode : SP/REC

MAIN CBA

TUNER

LINE

TUNER

58

41
38

CF301

4.5MHz
TRAP

CF302

4.5MHz
BPF

Q301

BUFFER

TU VIDEO TO VIDEO BLOCK

TU AUDIO

VIDEO
EXT V-IN

TO AUDIO BLOCK

FROM
VIDEO BLOCK

TO SERVO/SYSTEM
CONTROL BLOCK

SCL
SDA

I2C-OPEN

IC201

(SYSTEM CONTROL/OSD)

56

CV-IN

WF18
WF17

OSD-R
OSD-G
OSD-B

OSD-BLK

V-SYNC

H-SYNC

64
63
62
60

59
58

WF10

23
22
21
24

20
19

SYNC
SEPARATION

CHROMA
TRAP

LUMA
SIGNAL
PROCESS

V-SYNC
PROCESS
CIRCUIT

5
6

H-SYNC
PROCESS
CIRCUIT

CIRCUIT

OSD MIX/RBG MATRIX/
BLANKING

CHROMA
BPF

CHROMA
SIGNAL
PROCESS
CIRCUIT

LINE

CLOCK
CONTROL
CIRCUIT

34

16
15
14

10
11
33

X301

3.58MHz

WF11

J233
B-OUT

CL504

BLUE4
GREEN3
RED

2

AFC
H-DRIVE
ACL
V-RAMP-NF
V-DRIVE

TO
CRT/H.V. BLOCK
CL504A

FROM/TO
CRT/H.V. BLOCK

T7300BLC1-8-7 1-8-8

CRT/H.V. Block Diagram

FROM
POWER SUPPLY BLOCK

+B

DEF+B

Q572

H.DRIVE

WF12

Q571

H.OUTPUT

T572

T571 F.B.T.

HV

F

S

FOCUS VR

REC VIDEO SIGNAL PB VIDEO SIGNAL

IC551 (V-DEFLECTION CONTROL)

THERMAL

7

AMP

1

6

PROTECTION

PUMP
UP

VCC

3

2

ANODE

Mode : SP/REC

WF13

5

CN571

L551
DEFLECTION-YOKE

5

4

3

1

V­DRIVE

H­DRIVE

FROM/TO
CHROMA/TUNER BLOCK

FROM
CHROMA/TUNER
BLOCK CL504

V-DRIVE
H-DRIVE
AFC
ACL
V-RAMP-NF

GREEN

BLUE

CL504A
2RED
3
4

10

11

8

7

9

6

SCREEN VR



FOCUS
SCREEN

ANODE

CL501ACL501
HEATER 33
P-ON+180V 11

1

5

3

4

MAIN CBA

JK501

FOCUS
SCREEN

GND

R
G
B

HEATER

V501
CRT

Q501

RED AMP



Q502

GREEN AMP

WF15WF14



BLUE AMP

Q503

WF16



CRT CBA

CN501

1-8-101-8-9

GND

T7300BLCRT

Power Supply Block Diagram

CAUTION !

Fixed voltage power supply circuit is used in this unit.
If Main Fuse (F601) is blown, check to see that all components in the power supply
circuit are not defective before you connect the AC plug to the AC power supply.
Otherwise it may cause some components in the power supply circuit to fail.

HOT CIRCUIT. BE CAREFUL.

4A/125V

CAUTION

FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,
REPLACE ONLY WITH THE SAME TYPE FUSE.
ATTENTION : POUR UNE PROTECTION CONTINUE LES RISQES
D'INCELE N'UTILISER QUE DES FUSIBLE DE MEMO TYPE.
RISK OF FIRE-REPLACE FUSE AS MARKED.

"This symbol means fast operating fuse."
"Ce symbole reprèsente un fusible à fusion rapide."

NOTE :
The voltage for parts in hot circuit is measured using
hot GND as a common terminal.

W601

DG601
DEGAUSSING
COIL

CN601

4A/125V

F601
4A/125V

SWITCHING

LINE
FILTER

Q601

L601

PS601

Q602

LIMITER

D603 - D606

BRIDGE
RECTIFIER

HOT COLD

T601

5

4

2

1

IC601

ERROR
VOLTAGE DET

4 1

16

15

14

13

12

11

IC602

Q608

Q611

Q610

+5V REG.
+5V REG.

+5V REG.

+8V REG.

Q607

Q606

Q609

+5V REG.

+B

DEF+B

AL+33V

TIMER+5V

P-ON+5V
P-ON+5V

P-ON+5V

AL+12V

P-ON+8V

AL+5V
AL+12V

P-SAFETY2
(TO PIN3 OF IC201)

Q612

P-DOWN
(TO PIN84 OF IC201)

1-8-11

3 2

Q604
FEED

BACK

VR601
+B ADJ.

Q605

MAIN CBA

IC301

P-ON-ON

1-8-12

+5.7V
REGULATOR

P-ON-H
(FROM PIN31 OF IC201)

4449

T7300BLP

Main 1/4 Schematic Diagram

A5

B5

C5

D5

E5

F5

G5

MAIN 1/4

Ref No. Position

ICS
IC201 D-3
IC202 F-4

TRANSISTORS
Q205 C-1
Q206 F-4

TEST POINTS

J116 D-5

CONNECTORS

CL201 G-2

A4

A3

B4

B3

C4

C3

D4

D3

E4

E3

F4

F3

G4

G3

A2

A1

B2

B1

C2

C1

D2

D1

E2

E1

F2

F1

G2

G1

1-9-3

1-9-4

1-9-5

T7300SCM1

Main 2/4 Schematic Diagram

H5

H4

I5

I4

J5

J4

K5 L5

K4

L4

REC Video Signal
REC Audio Signal

M5

M4

PB Video Signal
PB Audio Signal

N5

N4

MAIN 2/4

Ref No. Position

ICS
IC401 I-2
IC801 M-4

TRANSISTORS
Q401 K-2
Q402 L-4
Q491 L-2
Q871 I-2
Q872 I-2
Q873 I-1
Q874 I-1
Q875 I-1

TEST POINTS
J187 H-3
J188 L-2
J189 J-4
J190 J-2

CONNECTORS
CL401 H-4
CL402 H-1
CL403 H-1

CN802 N-4

H3

H2

I3

I2

J3

J2

K3

K2

L3

L2

M3

M2

N3

N2

H1

I1

1-9-6 1-9-7 1-9-8 T7300SCM2

J1

K1

L1

M1

N1

Main 3/4 Schematic Diagram

O5

O4

P5

P4

Q5

Q4

R5 S5

R4

S4

REC Video Signal
REC Audio Signal

T5

T4

PB Video Signal
PB Audio Signal

U5

U4

MAIN 3/4

Ref No. Position

ICS

IC301 R-2

TRANSISTORS
Q301 R-5
Q302 Q-3

TEST POINTS
J191 Q-3
J233 T-2
J234 T-2
J239 T-2
J262 T-1
J264 T-1

CONNECTORS

CN303 U-5

O3

O2

P3

P2

Q3

Q2

R3

R2

S3

S2

T3

T2

U3

U2

O1

1-9-9

P1

Q1

R1

1-9-10

S1

T1

U1

1-9-11

T7300SCM3

Main 4/4 Schematic Diagram

NOTE :
THE VOLTAGE FOR PARTS IN HOT CIRCUIT IS MEASURED USING
HOT GND AS A COMMON TERMINAL.

V5

W5

CAUTION !

Fixed voltage power supply circuit is used in this unit.
If Main Fuse (F601) is blown, check to see that all components in the power supply
circuit are not defective before you connect the AC plug to the AC power supply.
Otherwise it may cause some components in the power supply circuit to fail.

X5

CAUTION

FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,
REPLACE ONLY WITH THE SAME TYPE FUSE.
ATTENTION : POUR UNE PROTECTION CONTINUE LES RISQES

4A/125V

D'INCELE N'UTILISER QUE DES FUSIBLE DE MEMO TYPE.
RISK OF FIRE-REPLACE FUSE AS MARKED.

"This symbol means fast operating fuse."
"Ce symbole reprèsente un fusible à fusion rapide."

Y5 Z5

AA5

BB5

PB Video SignalREC Video Signal

CRT

Ref No. Position

TRANSISTORS
Q501 AA-5
Q502 AA-4
Q503 AA-4

CONNECTORS
CL501A Z-5
CL504A Z-5

CN501 BB-4

V4

V3

V2

W4

W3

W2

X4

X3

X2

Y4

Y3

Y2

Z4

Z3

Z2

AA4

AA3

AA2

BB4

BB3

BB2

MAIN 4/4

Ref No. Position

ICS
IC551 V-5
IC601 Z-2
IC602 X-3

TRANSISTORS
Q571 X-5
Q572 X-5
Q591 X-4
Q601 AA-2
Q602 AA-2
Q604 Z-2
Q605 Y-2
Q606 Y-3
Q607 X-2
Q608 W-2
Q609 X-2
Q610 X-2
Q611 W-1
Q612 W-2

TEST POINTS
J551 Y-4
J552 Y-4

CONNECTORS
CL501 Z-5
CL504 Z-5

CN571 W-5
CN601 BB-2

ADJUSTMENT

VR601 Z-2

V1

1-9-12

W1

X1

Y1

VOLTAGE CHART (Power off mode)

Ref. No. S D G

Q601 0.0 137.0 1.8

Ref. No. E C B

Q602 0 3.2 0.5
Q605 0 7.0 0

Z1

1-9-13 1-9-14 T7300SCM4

AA1

BB1

Q606 7.0 7.0 7.0
Q608 5.0 7.5 5.7
Q609 6.0 6.5 6.6

Q610 0.7 4.7 1.3
Q611 0 2.4 0
Q612 5.3 5.3 0.8

WAVEFORMS

WAVEFORM NOTES

INPUT: NTSC COLOR BAR SIGNAL
OTHER CONTROLS: CENTER POSITION
VOLTAGES SHOWN ARE RANGE OF
OSCILLOSCOPE SETTING

2 V 5 ms

WF1 MAIN 2/4 SCHEMATIC DIAGRAM
J190 RF-SW

0.2 V 0.1 µs

WF2 MAIN 2/4 SCHEMATIC DIAGRAM
IC401 PIN 61

0.5 V 20 µs

WF5 MAIN 2/4 SCHEMATIC DIAGRAM
J188 V-OUT

0.2 V 5 V 5 ms

Upper: WF6 Lower: WF1
MAIN 2/4 SCHEMATIC DIAGRAM
J189 PB-C-MONI

0.5 V

WF9 MAIN 2/4 SCHEMATIC DIAGRAM
IC401 PIN 7

2 V

WF10 MAIN 3/4 SCHEMATIC DIAGRAM
IC301 PIN 20

0.5 ms

5 ms

10 V 5 ms

WF13 MAIN 4/4 SCHEMATIC DIAGRAM
CN571 PIN 5

20 V 20 µs

WF14 CRT SCHEMATIC DIAGRAM
Q501 COLLECTOR

1 V

WF17 MAIN 1/4 SCHEMATIC DIAGRAM
IC201 PIN 58

1 V 5 ms

WF18 MAIN 1/4 SCHEMATIC DIAGRAM
IC201 PIN 59

20 µs

1 V 10 ms

WF3 MAIN 1/4 SCHEMATIC DIAGRAM
J116 CTL

0.25 V 20 µs

WF4 MAIN 2/4 SCHEMATIC DIAGRAM
IC401 PIN 42

0.2 V 0.5 ms

WF7 MAIN 3/4 SCHEMATIC DIAGRAM
IC301 PIN 48

0.5 V 0.5 ms

WF8 MAIN 2/4 SCHEMATIC DIAGRAM
J187 A-OUT

1 V 20 µs

WF11 MAIN 3/4 SCHEMATIC DIAGRAM
IC301 PIN 11

20 µs200 V

WF12 MAIN 4/4 SCHEMATIC DIAGRAM
Q571 COLLECTOR

20 V 20 µs

WF15 CRT SCHEMATIC DIAGRAM
Q502 COLLECTOR

20 V 20 µs

WF16 CRT SCHEMATIC DIAGRAM
Q503 COLLECTOR

Z11WF1-10-1 1-10-2

ANODE

SP801
SPEAKER

CL802

WIRING DIAGRAM

CN802
SP1
SP-GND

2

WIRING DIAGRAM FOR SECTION 2
(DECK MECHANISM)

CAPSTAN MOTOR

CRT

HD

VD

D.Y.

GND

3
2
1

CN501

CL501B

HEATER
3

CL501A
HEATER
GND
P-ON+180V

CN571
1
2
3
4
5

FOCUS

GND

P-ON+180V
1

2

CRT CBA
BT5300F01012

SCREEN

T571
FBT

CL504B

GND
RED
GREEN
BULE

CL201

C-F/R
AL+12V

CL504
GND

1
2
3
4

1
2
3
4

RED
GREEN
BLUE

D/L+12V
AL+5V
GND
C-FG
C-CONT
GND
D-FG
LD-CONT
D-CONT
D-PG

CL401
V(R)
V-COM
V(L)

1
2
3
4
5
6
7
8

9
10
11
12

1

2

3

M LOADING

MOTOR

CYLINDER ASSEMBLY

PG
SENSOR

M

DRUM
MOTOR

VIDEO
(R)
HEAD

VIDEO
(L)
HEAD

(NO CONNECTION)
CN303 IS USED FOR

ADJUSTMENT AT
FACTORY

W601

CN303

INT.MONITOR

1

I2C-OPEN

2
3

GND
SDA

4

SCL

5

CN601
1
2

MAIN CBA
BT5300F01012

CL402

AE-H 1
AE-H/FE-H 2
A-COM
A-PB/REC
CTL(+)
CTL(-) 6

CL403

FE-H
FE-H GND

3
4
5

1
2

1-11-1 T7300WI1-11-2

CN287

1
2

3
4
5
6

AUDIO ERASE
HEAD

AUDIO HEAD

CONTROL HEAD

AC HEAD ASSEMBLY

FE HEAD

FULL ERASE HEAD