Sony TRINITRON GDM-1601 User manual

SONY.
TRINITRON® Graphic Display Monitor
GDM-1601/1602
REVISED
SERVICE MANUAL

':"ji:.
:. (J)"'<''='.:I. 7' )vt:g[,!Jt~ n l L'~$~(J)~fFti';I: ~Ut: i£1:> I). gll.sJlI*.i$,aUHIV .. ~(J)~
ffl~l3Jr-Jt LlL'*To
~')l. ~:f±(J)~f"iiJttLt:1!nJTl·~~Lt:I). gll.sJlI*.i$(tIH'F. i*;f~)t~tt~l3Jr-Jl'*
"'<''='.:I. 7' )v~~fflT ~:. t ~~LI:. L. *To
CONFIDENTIAL
The material contained in this manual consists of information that is the property
of Sony Corporation and is intended solely for use by the purchasers of the equip-
ment described in this manual.
Sony Corporation expressly prohibits the duplication
of any portion of this manual
. or the
use thereof for any purpose other than the operation or maintenance of the
equipment described in this manual
without the express written permission of Sony
Corporation.
CONFIDENTIEL
Le materiel contenu dans ce manu.el consiste en informations qui sont la propriete
de Sony Corporation et sont destinees exclusivement a I'usage des acquereurs de
I'equipement decrit dans
ce manuel.
Sony Corporation
interdit formellement la copie de quelque partie que ce soit de ce
manuel ou son emploi pour tout autre but que des operations ou entretiens de
I'equipement amoins d'une permission ecrite de Sony Corporation.
VERTRAULICH
Das in dieser Anleitung enthaltene Material besteht aus Informationen, die Eigen·
tum der Sony Corporation sind, und ausschlieBlich zum Gebrauch durch den
Kaufer der in dieser Anleitung beschriebenen Ausrustung bestimmt sind.
Die Sony Corporation untersagt ausdrucklich die Vervielfaltigung jeglicher Teile
dieser Anleitung oder den Gebrauch derselben
fur irgendeinen anderen Zweck als
die Bedienung oder Wartung der in dieser Anleitung beschriebenen Ausrustung
ohne ausdruckliche schriftliche Erlaubnis der Sony Corporation.
SAFETY·RELATED COMPONENT WARNING !!
COMPONENTS IDENTIFIED BY SHADING AND MARK
&. ON THE SCHEMATIC DIAGRAMS, EXPLODED
VIEWS
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. CIRCUIT ADJUSTMENTS
THAT ARE CRITICAL TO SAFE OPERATION ARE
IDENTIFIED IN THIS MANUAl. FOLLOW THESE PRO·
CEDURES WHENEVER
CRITICAL COMPONENTS ARE
REPLACED
OR IMPROPER OPERATION IS SUSPECTED.
ATTENTION AUX COMPOSANTS RELATIFS A LA
SECURITE!!
LES COMPOSANTS
IDENTIFIES ;>AR LINE TRAME ET
PAR
UNE MARQUE &SUR LES SCHEMAS DE PRINCIPE,
LES VUES EXPLOSEES ET LES LISTES DE PIECES
SONT
D'UNE IMPORTANCE CRITIQUE POUR LA
SECURITE DU FONCTIONNEMENT. NE LES REM-
PLACER QUE PAR DES COMPOSANTS SONY
DONT Lt:
NUMERO DE PIECE EST INDIQUE DANS LE PRESENT
MANUEL OU DANS DES SUPPLEMENTS PUBLIES PAR
SONY. LES REGLAGES DE
CIRCUIT DONT L'IMPOR-
TANCE EST CRIT.QUE POUR LA SECURITE DU
FONCTIONNEMENT SONT .IDENTIFIES DANS LE
PRESENT
MANUEL. SUIVRE CES PROCEDURES LORS
DE CHAQUE REMPLACEMENT
DE COMPOSANTS
CRITIQUES,OU LORSQU'UN MAUVAIS FONCTIONNE-
MENT EST SUSPECTE.

LIST OF DIFFERENT POINTS (GDM -1601/1602)
This service manual has been prepared for GDM -160l.
Redraw the CIRCUIT DIAGRAM of SECTION 5, EXPLODED VIEWS of SECTION 6, and ELECTRICAL
PARTS LIST of SECTION 7 in accordance
with the list of different points when using this manual
for GDM -1602.
Change the H period in the waveform diagram in the CIRCUIT DIAGRAM of SECTION 5 from
15.5 to 21 /J. sec and the voltage from +B145 to 120 V.
--------
GDM-1601 GDM-1602
L Board Part No. Description
Part No.
Description
A-1235-013-A L BOARD COMPLETE A-1235-011-A L BOARD COMPLETE
C41 1-136-091-00 FILM 0.0068MF
3%
2KV 1-136-139-00 FILM 0.012MF
3%
2KV
POWER BLOCK
Part No. A-1477-875-A
Part No.
A-1477-873-A
ASSY
G
Board IC51 1-235-843-11 POWER MODULE (DM-28) 1-235-844-11 POWER MODULE CDM-32)
-1-

-----
GDM-1601
GDM-1602
D Board Part No.
Description
Part No. Description
A-1345-676-A D BOARD
COMPLETE A-1345-722-A D BOARD COMPLETE
C110 1-130-475-00 MYLAR 0.0022MF
5% 50V 1-130-481-00 MYLAR 0.0068MF 5% 50V
C211 1-102-961-00 CERAMIC 27PF
5% 50V 1-102-953-00 CERAMIC 18PF 5% 50V
C219 1-136-121-00 FILM
0.27MF 5% 400V 1-136-133-00 FILM 0.43MF 5% 400V
C220 1-136-103-00 FILM
O.lMF
5%
200V 1-136-060-00 FILM 0.047MF 5% 400V
C224 1-130-908-00 FILM 0.0039MF
3% 1.6KV 1-136-178-00 FILM 0.0047MF 3%
1.6KV
C310 1-136-070-00 FILM 0.005MF
3%
2KV 1-136-098-00 FILM 0.0073MF
3%
2KV
D202 8-719-909-83 DIODE
ISS83
R137 1-249-405-11 CARBON 100
5% l/6W
1-247-811-00 CARBON 150 5%
1/6W
R240 1-215-451-00
METAL 18K
1%
1/6W
1-215-461-00
METAL
47K 1%
l/6W
R246 1-215-459-00
METAL 39K
1%
1/6W
1-215-451-00 METAL 18K 1%
1/6W
R253 1-249-435-11 CARBON 33K
5%
l/6W
1-249-433-11 CARBON 22K
5% 1/6W
R257 1-214-913-00 METAL
lOOK
1%
l/2W
1-214-907-00 METAL 56K 1%
1/2W
R268 1-215-459-00 METAL
39K
1%
l/6W
1-215-487-00 METAL 560K
1% 1/6W
R272 1-215-415-00
METAL 560
1% 1/6W
1-215-447-00 METAL
12K
1% 1/6W
R273 1-215-415-00
METAL 560 1% 1/6W
R274 1-214-767-00
METAL 39K 1% 1/4W
R301 1-215-919-11
METAL OXIDE 2.2K 5% 3W F 1-215-918-00 METAL OXIDE 1.5K
5%
3W
F
R302 1-216-438-11
METAL OXIDE 8.2K 5%
lW F 1-215-874-11
METAL OXIDE 6.8K
5%
lW F
R303 1-215-874-11
METAL OXIDE 6.8K
5%
1W F 1-215-873-00
METAL OXIDE 4.7K 5% 1W F
R304 1-215-874-11
METAL OXIDE 6.8K 5%
lW F 1-215-873-00
METAL OXIDE 4.7K 5% lW F
R328 1-216-367-00
METAL OXIDE 0.68
5%
2W F 1-216-371-11 METAL OXIDE 1.5
5%
2W F
R335 1-215-446-00
METAL 11K 1%
l/6W
1-215-447-00 METAL 12K 1%
l/6W
RV205 1-224-251-XX RES~ AD], METAL GLAZE 4.7K 1-224-252-XX RES, ADJ, METAL GLAZE 10K
JSl
~
[K]
]S2
~
[K]
DD Board
D5 8-719-109-97 DIODE RD6.8ESB2 8-719-109-89 DIODE RD5.6ESB2
DE
Board
C4 1-130-475-00 MYLAR 0.0022MF
5% 50V 1-130-483-00 MYLAR O.OIMF 5% 50V
-2-

TABLE OF CONTENTS
1. GENERAL
2. DISASSEMBLY AND REPLACEMENT
3. CIRCUIT DESCRIPTIONS
4.
ADJUSTMENTS
5. DIAGRAMS
6. EXPLODED VIEWS
7. ELECTRICAL PARTS LIST

SECTION 1
GENERAL
TABLE OF CONTENTS
Section Title
1-1. Features (GDM-1601)
.............
1-2. Specifications (GDM-160l)
.........
1-3. Features (GDM-1602)
.............
1-4. Specifications (GDM-1602)
.........
1-5. Location and Function of Controls
....
1-1
1-1
1-2
1-2
1-3

,-,. FEATURES
Sony GDM·1601 is a highly integrated color display
monitor which is designed for displaying high resolution
graphics.
• The GDM-1601 high resolution graphic display monitor
employs the Super Fine·pitch TRINITRON® picture
tube.
• Resolution is extremely high with 1280 (horizontal) x
1024 (vertical) picture elements per frame, thus a high·
density color display can be obtained.
• A silica coating on the screen provides a glare-free
display.
.Cylindrical screen reduces distortion as viewed from
the sides, sharpens the picture corners, and
diminishes reflections.
• The display unit can be turned over 360 degrees to the
fight or left, and can be tilted 15 degrees up or 5 de-
grees down if SU-536 Display Stand is attached.
.Since the 60 Hz non·interlace method is employed,
display of little flicker can be obtained.
'-2. SPECIFICATIONS
System Raster scanning method (non·interlace)
RIGIB input, full color system
Picture tube
Sync on
green (internal sync). or separated/com.
posite sync
input (Automaticaly selected)
Super fine·pitch Trinitron color tube
0.26mmphosphor pitch with aparture grill
16 inches measured diagonally
90·degree deflection
Anti-reflective coating (silica coating)
Visual picture size
Approx. 295(h) x 236(w) mm (11
5
/8 x 9'/s
inches)
12BO(H) )( 1024(V) viewable pixels
Horizontal
deflection frequency (fh)
63.34 kHz
Vertical
deflection frequency (fv)
59.98 Hz
Video
amplifier
frequency band width
60 Hz·100 MHz ± 3 dB (TYP)
Signal In case
of composite signal
RIB video signal input:
Video
level-O.714 V p.p, positive
G video Signal input:
1.0 V p.p, composite,
Video
level-0.714 V p.p, positive
Sync
level-0.286 V p.p, negative
In case
of separate sync
RIGIB video signal input:
0.714 V p.p, positive
EXTERNAL SYNC input:
1.0-4.0 V p.p, negative
Connector type
BNC type 75 ohm input .impedance
Power requirements
100-120V±10%
220-240V±10%
50/60 Hz ±3 Hz
,-,
AC input current
100-120V: 2AA max.
220-240V:
1AA max.
Environmental conditions
Operati
ng temperature : 10°-40°C
Operating
humidity : 10·80%. condinsation
Storage temperature : 0°- 60°
Storage
humidity : 5 - 90%. condinsation
Dimensions
Weight
Approx. 406 x 380 x 450 mm (w/h/d)
(15.98 x 14.96 x 17.72 inches)
Approx. 406 x 406 x 450 mm (w/h/d)
SU·536 Display Stand
(15.98 x 15.98 x 17.72 inches)
Approx. 26.5 kg (58 Ibs)
Approx. 29 kg (64 Ibs) with SU-536 Display
Stand (optional)
Signal timing
Dot clock 9.24ns(108.18MHz)
Horizontal
.Horizontal
sync signal H-DISP H-BL
-I" "I
1"
fH=63.34kHz
H-DISP: Horizontal-display Period
active
H·FP: Horizontal-frontporch
H-SYNC: Horizontal-sync
H·BP: Horizontal-backporch
H-BL: Horizontal-blanking
1
H: 1 Horizontal total Period
Vertical
1H
11.832}Ls (1280 dot)
oA07}Ls
1.701/o1
s
1.849/015
3.956/015
15.788/015
44 dot)
184 dot)
200 dot)
428 dot)
(1708 dot)
V-DISP V-BL
Vertical
sync signal
fV=59.98Hz
I.
V·DISP: Vertical-display Period
active
time
V-FP: Vertical-frontporch
V-SYNC: Vertical-sync
V-BP: Vertical-backporch
V-BL: Vertical-blanking
1
V: 1 Vertical-total Period
kt~~
V-FP V-SYN~ V.BP
1V
16.162ms (1024 line)
47.35}Ls
47.35/015
41004/015
0.505ms
16.667ms
3 line)
3 line)
26 line)
32 line)
(1056 line)

1-3. FEATURES
Sony GDM·1602 is a highly integrated color display
monitor which is designed for displaying high resolution
graphics.
• The
GDM·1602 .high resolution graphic display monitor
employs the Super Fine·pitch TRINITRON" picture
tube.
• Resolution is extremely high
with 1 024 (horizontal) x
768 (vertical) picture elements per frame, thus a high·
density color display can be obtained.
.A silica coating on the screen provides a glare-free
display.
• Cylindrical screen reduces
distortion as viewed from
the sides, sharpens the picture corners, and
diminishes reflections.
• The display
unit can be turned over 360 degrees to the
right or left, and can be tilted 15 degrees up or 5 de-
grees down if SU-536 Display Stand is attached.
.Since the 60 Hz non·interlace method is employed,
display of little flicker can be obtained.
1-4. SPECIFICATIONS
System Raster scanning method (non·interlace)
R/G/B input, full color system
Picture tube
Sync on green (internal sync). or separated/com·
posite sync
input (Automaticaly selected)
Super fine·pitch Trinitron color tube
0.26mm phosphor pitch with aparture grill
16 inches measured diagonally
90-degree deflection
Anti-reflective coating (silica coating)
Visual
picture size
Approx. 295(h) x 221 (w) mm (11'/. x 8Y.
inches)
1024(H) x 768(V) viewable pixels
Horizontal deflection frequency (fh)
48.78 kHz
Vertical deflection frequency (fv)
60.0 Hz
Video amplifier
frequency band width
Signal
60 Hz·100 MHz ± 3 dB (TYP)
In case of composite signal
RIB video signal input:
Video level-0.714 V p.p, positive
G video signal input:
1.0 V p.p; composite,
Video level-0.714 V p.p, positive
Sync level-0 .. 286 V p.p, negative
In case of separate sync
R/G/B video signal input:
0.714 V p.p, positive
EXTERNAL SYNC input:
1.0-4.0 V p.p, negative
Connector type
BNC type 75 ohm input impedance
Power requirements
100·120V±10%
220·240V ± 10%
50/60 Hz ±3 Hz
1-2
AC input current
100·120V: 2.3A max.
220·240V: 1.3A max.
Environmental conditions
Operating temperature: 10°· 40°C
Operating humidity:
Storage temperature:
10 -80%, condinsation
0°.60°
Storage humidity:
5 - 90%, condinsation
Dimensions
Approx. 406 x 380 x 450 mm (w/h/d)
(15.98 x 14.96 x 17.72 inches)
Approx. 406 x 406 x 450 mm (w/h/d) with
SU-536 Display Stand
Weight
(15.98 x 15.98 x 17.72 inches)
Approx. 26.5 kg (58 Ibs)
Approx. 29 kg (64 Ibs) with SU-536 Display
Stand
(optional)
Signal timing
Dot clock
15.625ns (64 MHz)
Horizontal
Horizontal
sync signal
I-
H-DISP
,..-----------,
I.
~:tji
H·FP H·SYN~ H.BP
1H
fH=48.78kHz
H-DISP: Horizontal-desplay Period active
H-FP:
Horizontal·frontporch
H-SYNC: Horizontal-sync
H-BP: Horizontal·backporch
H-BL: Horizontal-blanking
1 H: 1 Horizontal total Period
Vertical
16.0J,LS
1.0J,Ls
1.5J,Ls
2.0J,Ls
4.5J,Ls
20.5J,Ls
(1024 dot)
( 64 dot)
( 96 dot)
( 128 dot)
( 288 dot)
(1312 dot)
Vertical
sync signal
V·DISP V·BL
1V
fV=60.0Hz
V-DISP: Vertical·desplay Period active
time
V-FP: Vertical-frontporch
V-SYNC: Vertical·sync
V-BP: Vertical-backporch
V-BL:
1V:
Vertical·blanking
1 Vertical·total Period
~
V.FP V-SYNC V-BP
15.744ms (768 line)
61.5J,Ls
61.5J,Ls
799.5J,Ls
922.5J,Ls
16.667ms
3
line)
3 line)
39 line)
45 line)
(813 linld

1-5. LOCATION AND FUNCTION OF CONTROLS
rr=---~--~-~-. ~~~~]
I I II
I I
I
I
II
L~""""",, __ ~-- ~=""""IJ
I
/r-
r • I
• I
WWW
4 I I
W SU-536
0 0
~~:
19J
~
~ c ,
[[;l~ ~_QJ~
!
.~
A
Ir
~\
I
l~
! 1
I
~
I
[I] 7 []]
1-3.
mvSTAT (vertical static convergence) control
Adjusts the red and the blue horizontal lines so that they
converge
with the green horizontal line.
mH STAT (horizontal static convergence) control
Adjusts the red and the blue vertical lines so that they
converge
with the green vertical line.
mV CENT (vertical centering) control
Centers the picture in the vertical direction.
WContrast control (et)
Adjusts the picture contrast.
WPower switch and indicator
WVoltage selector (under the cover) and fuse
Use the monitor with the appropriate selector setting and
fuse.
The voltage selector
is set to the 100 -120 V position and
a 4-ampere 125 V fuse is attached
at the factory. When
using
the monitor in any other voltage area, the selector
must be reset and the supplied T3.15-ampere 250 V fuse
must be used. Refer this service to qualified personnel.
II] AC IN connector
[II] VIDEO IN connectors (BNC)
Accept RGB video signals (0.714 Vp-p, positive).
When
no external sync signal is applied, an internal sync
signal (0.286 Vp-p, negative)
must be added to the G
Signal.
[I] SYNC IN (external sync input) connectors (BNC, 75
ohms)
Accept external sync signals
(1 - 4 Vp-p, negative).
HD: for horizontal drive pulse
or composite sync.
VD: for vertical drive pulse
When an external sync signal is applied, the
monitor is
automatically switched from the internal sync mode to
the external sync mode.

SECTION 2
DISASSEMBLY AND REPLACEMENT
TABLE OF CONTENTS
Section Title
2-1. Rear Cabinet Removal. . . . . . . . . . . .. 2-1
2-2. Location of Rear Panel ............ 2-1
2-3. Location of Adjustment for A Board 2-2
2-4. Location
of Adjustment for L Board 2-2
2-5. Location
of Adjustment for D Board 2-3
2-6. Location
of Adjustment for Focus,
Screen and H. Stat
............... 2-3
2-7. Bezel Removal . . . . . . . . . . . . . . . . .. 2-4
2-8. Control Block Removal . . . . . . . . . .
.. 2-4
2-9. Switching Regulator Unit and
Convergence
PCB Removal . . . . . . . . .. 2-5
2-10. Flyback Transformer Assy and
HV Block Removal . . . . . . . . . . . . . 2-6
2-11. Deflection PCB, Video Amp
PCB and
Arc Suppression
PCB Removal ....... 2-7
2-12. Picture Tube Removal . . . . . . . . . . .
.. 2-8

2-1. REAR CABINET REMOVAL
SECTION 2
DISASSEMBLY
®rear cabinet
® perforated metal shield
o two screws
2-2. LOCATION OF REAR PANEL
fuse
voltage
selector
~
ACIN
connector
-----
o two screws
~
i---
t'-..
fo-o
r-.f'0
to-c o 0
o~o
110001'0001
I ... '"'" 0 /
/
VIDEO IN
connector
2-1
I---
\
SYNC IN
connector
o four screws

2-3. LOCATION OF ADJUSTMENT FOR A BOARD
RV403
8·DRIVE
RV402
G·DRIVE
2-4. LOCATION OF ADJUSTMENT FOR L BOARD
RV1
V.STAT H.COMV
oap
RV2
TOP RV1
RV4 RVe
RV3
CENTER RV2
/
RV7
BOTTOM RV3 RV5 RVa
2-2
RV401
R-DRIVE
RV405
8-8KG
RV4
RV404
G·8KG
RVe
RV7
RVa
l2 SIN ADJ
0

2-5_ LOCATION OF ADJUSTMENT FOR D BOARD
RV10l V.SIZE
RV102
V.LlNEARITY
RV103
V.LlNEARITY BALANCE
RV104
BOT AMP
RV105
BOT PHASE
RV108
RV106
TOP AMP
RV102
RV107
TOP PHASE
RV103
RV108 V.CENTER
RV201 KEY
RV202 KEY BALANCE
RV203
PIN AMP
RV10l
RV106
"'-
j
....
-
-]
p 0
,,\, ~f.yRV107
_ '-; ;::,--RV104
0
-,;,; ':~RV105
/~RV203
-
o RV204 ". ')(~
D
RV206 /' ~ RV201
.~ ~.
I~
/_. l)RV2~;
o RV208 RV205
RV202
RV301
RV204 H.SIZE
RV205 H.PHASE
RV206 SIDE PIN
BALANCE
~
::=1
1
-
RV207 H-FREQUENCY
RV208 H-CENTER
RV301
HV ADJ
2-6. LOCATION OF ADJUSTMENT FOR FOCUS, SCREEN AND H. STAT
H.STAT
2-3

2-7. BEZEL REMOVAL
two washers
obezel
2-8. CONTROL BLOCK REMOVAL
ocontrol block
(j) two screws
2-4

2-9. SWITCHING REGULATOR UNIT AND CONVERGENCE PCB REMOVAL
([) one screw I
®switching I
regulator I
unit
I
2-5
---,
. I
SIX screws I
I
I
I
I
I
I
I
two washers I
I

2-10. FLYBACK TRANSFORMER ASSY AND HV BLOCK REMOVAL
oflyback transformer assy
and HVblock
®anode cap
2·6

2-11. DEFLECTION PCB, VIDEO AMP PCB AND ARC SUPPRESSION PCB REMOVAL
o ~hield "A"
® video amp PCB
(]) two screws ® three screws
® I/O panel assy
odeflection PCB
2-7

2-12_
PICTURE TUBE REMOVAL
(j)
anode cap
o
four
flange
nuts
• ANODE CAP REMOVAL
o
Turn
up
one
side
of
the
rubber
cap
in
the
direction
indicated
by
the
arrow
®.
Anode
button
(])
three screws
o110
panel
assy
oUsing a
thumb,
pull
up
the
rubber
cap
firmly
in
the
direction
indicated
by
the
arrow@.
oWhen
one
side
of
the
rubber
cap
is
separated
from
the
anode
button,
the
anode
cap can
be
removed
by
turning
up
the
rubber
cap
and
pulling
up
it
in
the
direction
of
the
arrow@).
2-8

SECTION 3
CIRCUIT DESCRIPTIONS
TABLE OF CONTENTS
Section Title
3-1. A Board . . . . . . . . . . . . . . . . . . . . .. 3-1
3-li-l. Composition . . . . . . . . . . . . . . . .. 3-1
3-1:-2. Contrast Amplifier (AA Board) . . . .. 3-1
3-1-3. Pedestal Clamp (AA Board) ....... 3-1
3-14. Sync Separator and Pulse Generator
(AB Board) . . . . . . . . . . . . . . . .
.. 3-1
3-1-5. Video Output Amplifier. . . . . . . . .. 3-1
3-1-6. Blanking Amplifier. . . . . . . . . . . .. 3-2
3-2. B Board
...................... 3-2
3-3. C Board
...................... 3-2
3-4. D Board (Deflection and
HV Regulation)
... . . . . . . . . . . . . .. 3-2
3-4-1. DA Board . . . . . . . . . . . . . . . . .
.. 3-2
34-2. DB Board ... . . . . . . . . . . . . . . .. 3-2
34-3. DC Board . . . . . . . . . . . . . . . . . .. 3-2
3-44. Horizontal Deflection Output
Circuit '" ................. , 3-3
3-4-5. Vertical Deflection
Output . . . . . . .. 34
3-4-6. Blanking Pulse Generator. . . . . . . .. 34
3-4-7. HV Regulator ................ 3-4
Section Title
3-4-8. HV Hold-Down Circuit
3-4-9. Beam
Protector .............. .
34-10. Scan Failure Protection ......... .
3-5. G Board (Power Supply)
.......... .
3-5-1.
AC Line Filter ............... .
3-5-2.
AC Voltage Selector ........... .
3-5-3. Degauss
................... .
3-54. OVP Circuit ................. .
3-5-5.
DC Power Supply (Regulator) ..... .
3-6. H Board
..................... .
3-7. J Board
...................... .
3-8. L Board
..................... .
3-8-1. Composition '
................ .
3-8-2. Modulated Waveform Generator
... .
3-8-3. Horizontal Convergence
......... .
3-84. Vertical Convergence ........... .
3-8-5. Dynamic Quadrapole (DQP) Drive . . .
3-5
3-5
3-5
3-5
3-5
3-5
3-5
3-5
3-5
3-6
3-6
3-6
3-6
3-6
3-6
3-6
3-6

3-1_ A BOARD
3-1-1. Composition
The A board consists of three channels of video signal
amplifiers
that include a contrast control circuit,
pedestal clamp circuit,
output amplifier (main), and
blanking circuit. In addition, a sync signal separator
and various control pulse generators are also located
on the A board. Each of the three AA boards,
mounted on the A board, consists of a contrast ampli-
fier and clamp circuit. The
AB board, also mounted
on the A board, includes a sync signal separator and
c'ontrol pulse generators.
3-' -2. Contrast Amplifier (AA Board)
The contrast control amplifier utilizes a differential
amplifier for
current balance control and a feedback
circuit
to obtain wide frequency response and good
tracking between channels. In this circuit, the ampli-
fier gain can be
continuously changed by DC adjust-
ment for contrast control. This is achieved with the
following signal process. A reference pulse is inserted
on the back porch of the input signal (output of
buffer QI).
video signal
I
t
sync pulse
Fig. 3-1 Reference Pulse
The signal is then input to the conttast amplifier con-
sisting
of Q2 thru Q7. The gain is determined in the
differential amplifier, Q3 and Q4, by altering the
balance of the collector currents. Q8 thru Q13 are
preamplifiers. The amplified signal is
then buffered
by QI4 and input to a sampling circuit for feedback.
Q
15 samples the magnitude of the reference pulses
and charges CI O. Meanwhile, a DC voltage, deter-
mined by the
contrast control VR (H board) via
RV401
(R-DRV), is input at pin G) of IC1 (2/2).
IC I (2/2) outputs a DC voltage to the base of Q6 so
that the sampled voltage at pin ® is compared with
that 'at pin G). By feeding back the output of ICI
(2/2) to the contrast amplifier, the reference pulse
level becomes equal
to the potential difference be-
tween the two inputs of ICI (2/2). Contrast can be
changed
by RV4 on the H board, as explained.
3-1
3-' -3. Pedestal Clamp (AA Board)
This circuit performs pedestal clamping for DC resto-
ration of the input signal since the input stage of the
video amplifier is AC coupled. Altering the DC bias
at the collector of Q4 restores the DC component of
the input signal and stabilizes the pedestal level
(black)
of the signal at the CRT cathode. Q5 acts as a
DC
power supply to regulate a bias voltage to Q4.
The emitter voltage of Q5 is controlled by the output
from IC I (1/2), which is a high gain DC 'lmplifier. A
reference voltage (DC) is
provided at pin ® of IC 1:
and a feedback voltage subtracted by QI7 from the
final video stage is at pin (}). Q17 samples and holds
the detected voltage at RIl1 activating the gate by a
background pulse. IC 1 (1/2) compares the two input
voltages and the output, thru Q5, controls the DC
level of the collector of Q4 so as to equalize the input
voltages.
3-1-4. Sync Separator and Pulse Generator
(AB Board)
The sync separator, consisting of QI thru Q3, distin-
guishes
the sync portion of the composite video
signal
and separates the sync pulses into horizontal
sync (HD) and vertical sync (VD). When external
sync signals are input to the monitor, the two sync
signals are directly
input to pins (}) (X2) and ®
(X I) of IC1, the data selector. IC I detects external
sync pulses and automatically selects data lines X2
and
XI. If no external sync pulses are detected, data
lines Y2 and Y I, internal sync, are selected. HD and
VD pulses are then sent to the D board via the B
board.
Meanwhile, the pulses output from pin @ of IC I
trigger IC2
(1/2), a monostable multivibrator. A
background pulse is generated, synchronized with
HD, and is output thru Q6 and Q7. At the same
time, IC2
(2/2) is triggered by the background pulse
and generates
the contrast control pulse.
3-'-5. Video Output Amplifier
The video signals from the AA board preamplifier are
input to the base of QI01. The video output stage is
composed of a cascade amplifier consisting of QI0 I
and QI
02 and has a gain of 20 dB. The frequency
response of ±3 dB from 60 Hz to 100 MHz is opti-
mized with parallel peaking (Ll 0 I), series peaking
(Ll 02), and emitter peaking (QI0 I), which compen-
sate for the high frequency response.