Sony Trinitron PVM-1271Q User manual

PVM-1271Q
I
SERVICE MANUAL
October, 1984
US Model
Chassis No. SCC-611A-A
US Model
Canadian Model
Chassis No. SCC-585A-A
SPECIFICATIONS
Color system PAL, SECAM, NTSC and NTSC4.43 systems,
switched automatically
Picture tube Trinitron tube
Approx. 33 cm (13 inches), 90 degree deflec¬
tion, Super Fine Pitch 6.25 mm
(Approx. 31 cm picture measured diagonally)
Resolution RGB inputs : 600 iines, 640 x 200 dots
Composite input: 550 lines
Color temperature PVM-1271Q: 9,300°K
PVM-1371QM; 6,500OK
(Can be changed to either temperature by
an internal switch. For switching of the col¬
or temperature, consult your authorized
Sony dealer.)
Frequency response 10 MHz (-3 dB, RGB)
5.5.MHZ (-3 dB, composite video)
Horizontal linearity ±8%
Verticai iinearity ±5%
Line pull range Horizontal ±500 Hz
Vertical s Hz
Overscan of the picture
5%
Underscan of the picture
Return loss
Zooming
Convergence
4 MHz, 35 dB (LINE A, LINE B)
Within 2%
Central area 0.6 mm
Periphery 0.8 mm
More than 35 foot-lamberts
Inputs p VIDEO IN: BNC connector
*-VTR ; 8-pin connector, Pin No. 2 (pin No. .
6: ground)
composite 1 Vp-p +6 dB, sync negative,/
75 ohms and high impedance switchatf
p AUDIO IN: minijack
■ - VTR : 8-pin connector. Pin No. 1 (pin 1^
5: ground)
-5dBs, high impedance
EXT SYNC IN: BISC connector
composite sync 2-8 Vp-p, negative,
75 ohms and high impedance switchable
RGB IN : BNC connector
0.7 Vp-p, ±6 dB, 75 ohms, non composite
AUDIO (RGB) IN : mini jack
-5 dBs, high impedance
CMPTR: 25-pin connector
For details, see “CMPTR connector”
Outputs VIDEO OUT: BNC connector
AUDIO OUT: mini jack
Output level 1 W
EXT SYNC OUT: BNC connector
RGB OUT : BNC connector
AUDIO (RGB) OUT: mini jack
Loop-through
Power requirements PVM-1271Q: 120 V ac, 50/60 Hz
PVM-1371QM: 220 - 240 V ac, 50/60 Hz
Power consumption PVM-1271Q: 105 W
PVM-1371QM: 90 W
Dimensions Approx. 346 x 330 x 387 mm (w/h/d)
(13V» X 13 X 15‘/4 inches)
Weight
Approx. 14.5 kg (31 lb 15 oz)
TRINITRON®
COLOR VIDEO MONITOR
1203

J
i /
CMPTR connector (25-pin)
Pin assignment
Pin No
■ Signal
Signal level -
IBM select
Highs*ate(5V): IBM mode
Low state: 3 Bit TTL
2
Audio select
High state (5 V or open): Audio inputs from pin 13. ^
Low state (less than 0.4 V): Audio inputs from the LINE A AUDIO IN jack
3
H. sync or composite sync
Negative polarity -
When the high state is selected at pin 9:
1 V p-p, 75-ohm terminated
When the low state is selected at pin 9 ■
m level
4
Blue input
Positive polarity
When the high state is selected at pin 9 •
5
6
7
Green input
Red input
12 V power supply
Analog signal (0.7 V p-p, 75-ohm terminated, non sync)
When the low state is selected at pin 9:
Digital signal (TTL level)
8
5 V power supply
0.6 A max -----
9*
Analog/digital mode select
High state (open): Analog signal (0.7 V p-p)
Low state (ground); Digital signal (TTL level)
Pin No.
Signal
Signal level ~ -
10
RGB/NORMAL mode select
High state (5 V or open): RGB inputs from a microcomputer
Low state (ground): Composite video inputs from the LINE A VIDEO IN connector
11
V-sync
Negative polarity
TTL level
12
Blanking
High state (5 V or open): Video inputs from a microcomputer only
Low state (ground): Composite video input from the LINE A VIDEO IN connector
During the low state, the video signal from the microcomputer is blanked and the
^ -
13
Audio input
Input level -5 dB (100% modulation), input impedance more than 47 k ohms
15-24
EXT/INT mode sync switch
Ground
High state (open): Sync signal input from the CMPTR connector
LOW state: Sync signal input from the LINE A VIDEO IN connector
25*
IBM luminance signal
Positive polarity
When the high state is selected at pin 1 • TTL level
When the low state is selected at pin 1: Low state (qroundi
♦ Examples for microcomputer connections
No.
Microcomputer\
9
25
SMC-70/SMC-70G
-
High state
IBM computer
High state
Low state
IBM luminance signal
TTL 3BIT computer
Low state
Low state
Low state
Wh. e the information given is true at the time of printing, small pro¬
duction changes in the course of our company's policy of improve-
men through research and design might not necessarily be in¬
dicated in the specifications. We would ask you to check with your
appointed Sony dealer if clarification on any point is required.
- 2 -

SAFETY CHECK-OUT
PVM-1271G ■
After correcting the original service problem,
perform the following safety checks before releasing
the set to the customer:
1. Check the area of your repair for unsoldered or
poorly-soldered connections. Check the entire
board surface for solder splashes and bridges.
2. Check the interboard wiring to ensure that no
wires are “pinched” or contact high-wattage
resistors.
3. Check that all control knobs, shields, covers,
ground straps, and mounting hardware have
been replaced. Be absolutely certain that you
have replaced all the insulators.
4. Look for unauthorized replacement parts, par¬
ticularly transistors, that were installed during a
previous repair. Point them out to the customer
and recommend their replacement.
5. Look for parts which, though functioning, show
obvious signs of deterioration. Point them out
to the customer and recommend their replace¬
ment.
6. Check the line cord for cracks and abrasion.
Recommend the replacement of any such line
cord to the customer.
7. Check the condition of the monopole antenna
(if any).
Make sure the end is not broken off, and has
the plastic cap on it. Point out the danger of
impalement on a broken antenna to the
customer, and recommend the antenna’s
replacement.
8. Check the B+ and HV to see they are at the
values specified. Make sure your instruments
are accurate; be suspicious of your HV meter
if sets always have low HV.
9. Check the antenna terminals, metal trim,
“metallized” knobs, screws, and all other
exposed metal parts for AC leakage. Check
leakage as described below.
To Exposed Meta!
Parts on Set
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
LEAKAGE TEST
The AC leakage from any exposed metal part to
earth ground and from all exposed metal parts to any
exposed metal part having a return to chassis, must
not exceed 0.5 mA (500 microampers). Leakage
current can be measured by any one of three
methods.
1. A commercial leakage tester, such as the
Simpson 229 or RCA WT-540A. Follow the
manufacturers’ instructions to use these instru¬
ments.
2. A battery-operated AC milliammeter. The Data
Precision 245 digital multimeter is suitable for
this job.
3. Measuring the voltage drop across a resistor by
means of a VOM or battery-operated AC'volt-
meter. The “limit” indication is 0.75 V, so
analog meters must have an accurate low-
voltage scale. The Simpson 250 and Sanwa
SH-63Trd are examples of a passive VOM that
is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are
suitable. (See Fig. A)
HOW TO FIND A GOOD EARTH GROUND
A cold-water pipe is guaranteed earth ground; the
cover-plate retaining screw on most AC outlet boxes is
also at earth ground. If the retaining screw is to be
used as your earth-^ound, verify that it is at ground
by measuring the resistance between it and a cold-
water pipe with an ohmmeter. The reading should be
zero ohms. If a cold-water pipe is not accessible,
connect a 60—100 watts trouble light (not a neon
lamp) between the hot side of the receptacle and the
retaining screw. Try both slots, if necessary, to locate
the hot side of the line, the lamp should light at
normal brilliance if the screw is at ground potential.
(See Fig. B)
- 3 -

PVM-1271Q
TABLE OF CONTENTS
Section Title Page
1. GENERAL
1 -1. Features. 5
1-2. Precautions. 5
1-3. Location of Controls. 6
1-4. Function of Controls. 7
1- 5. System Connections. 9
2. DISASSEMBLY
2- 1. Cabinet Ass’y Removal. 12
2-2. B Board Removal. 12
2-3. Chassis Ass’y Removal. 13
2-4. F board Removal (1). 14
2-5. F board Removal (2). 14
2- 6. Picture Tube Removal. 15
3. ADJUSTMENTS
3- 1. Setup Adjustments. 16
3-1-1. Beam Landing. 16
3-1-2. Convergence. 17
3-1-3. Focus. 17
3-1-4. White Balance. 18
3-2. Safety Related Adjustments .-. 20
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY SHADING AND MARK
A 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.
'<1 Section Title Page
i 3-3. Circuit Adjustments . 23
3-3-1. D Board Adjustments .. 23
3-3-2. B Board Adjustments. 27
3-3-3. Q Board Adjustments. 31
4. DIAGRAMS
4-1. Block Diagram. 35
4-2. Circuit Boards Locating.. 38
4-3. Waveforms . 39
4-4. Schematic Diagram. 43
4-5. Printed Wiring Boards. 51
B Board. 51 .
D Board. 52
Q Board. 54
H Board. 55
Cl Board . 55
Cj Board . 57
F and F2 Boards. 58
4- 6. Semiconductors. 59
5. EXPLODED VIEWS
5- 1 . Cabinet. 50
5-2. Bezel. 61
5-3. Chassis. 62
6. E L ECTRICAL PARTS LIST
ATTENTION AUX COMPOSANTS RELATIFS A LA
SECURITEI!
LES COMPOSANTS IDENTIFIES PAR UNE TRAME ET
PAR UNE MARQUE i\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 LE
NUMERO DE PIECE EST INDIQUE DANS LE PRESENT
MANUEL OU DANS DES SUPPLEMENTS PUBLIES PAR
SONY. LES REGLAGES DE CIRCUIT DONT L'lMPOR-
TANCE EST CRITIQUE 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.
- 4 -

PVM-1271Q ^
SECTION 1
GENERAL
1-2. PRECAUTIONS
1-1. FEATURES
High-resolution picture
The Super Fine Pitch Trinitron picture tube (0.25 mm aper¬
ture grill) gives high resolution (composite: 550 iines,
RGB; 650 lines) picture. When used as a character display,
up to 2000 characters (80 characters/line x 25 lines) can be
displayed with great clarity.
Analog/digital RGB input
Analog RGB and digital (TTL level) RGB input signals can be
fed to the RGB input connectors (BNC type and 25-pin multi
connectors), which allows a microcomputer or a data infor¬
mation system such as teletext, to be connected to this
monitor.
Receives 4 TV broadcasting standards
This monitor can receive PAL, SECAM, NTSC and NTSC4 43 ♦
signals. The appropriate broadcasting standard is selected
automatically.
Colorpure Filter
When NTSC video signals are received, a colorpure filter ac¬
tivates to increase the resolution about 35%, resulting in
fine picture detail without color spill or color noise.
Underscan mode
The signal normally scanned outside of the screen can be
monitored in the underscan mode.
Automatic frequency control
The incoming sync timing error compensation speed can be
set to fast or slow, according to the input signal. In the slow
mode, the jitter from a video tape recorder can be easily
monitored.
Superimposition of a picture from a microcomputer on a pic¬
ture from video equipment
When a Sony SMC-70 or SMC-70G microcomputer, an
SMI-7073 superimposer and video equipment such as a
video disc player are used together with this monitor, a pic¬
ture from the microcomputer can be superimposed on a pic¬
ture from the video equipment.
♦ An NTSC443 system signal is obtained by playing back NTSC-recorded
video tapes with a video tape recorder/player specially designed for use with
this system.
On safety
• Check that the operating voltage of your unit is identical
with the voltage of your local power supply.
• Should any liquid or solid object fall into the cabinet,
unplug the unit and have it checked by qualified personnel
before operating it any further.
• Unplug the unit from the wall outlet if it is not to be used
for several days.
•To disconnect the ac power cord, pull it out by the plug.
Never pull the cord itself.
On installation
• Allow adequate air circulation to prevent internal heat
build-up.
Do not place the unit on surfaces (rugs, blankets, etc.) or
near materials (curtains, draperies) that may block the ven¬
tilation holes.
• Do not install the unit in a location near heat sources such
as radiators or air ducts, or in a place subject to direct
sunlight, excessive dust, mechanical vibration or shock.
On cleaning
To keep the unit looking brand-new, periodically clean it
with a soft cloth. Stubborn stains may be removed with a
cloth lightly dampened with a mild detergent solution. Never
use strong solvents such as thinner or benzine, or abrasive
cleansers since these will damage the cabinet. As a safety
precaution, unplug the unit before cleaning it.
On repacking
Do not throw away the carton and packing materials. They
make an ideal container in which to transport the unit. When
shipping the unit to another location, repack it as illustrated
on the carton.
If you have any questions about this unit, contact your
authorized Sony dealer.
By using an optional MB-502 mounting bracket, the PVM-
1271Q/1371QM can be mounted in an EIA standard 19-inch
rack. An optional SLR-102 slide rail is also available.
For mounting details, see the appropriate instruction
manual.
\
-5

Front panel
6

PVM-1271Q
1-4. FUNCTION OF CONTROLS
FRONT PANEL
O SECAM button
Press this button when a picture from SECAM color sources
is distorted. The picture wiil become clear.
O SYNC select switch
Sync may be supplied from an external sync generator to
the EXT SYNC IN connector on the rear PANEL. When an ex¬
ternal sync is supplied, with either a composite or non¬
composite video input, set the SYNC select switch to EXT.
When composite video is supplied with no external sync, set
the SYNC select switch to INT.
O AFC (automatic frequency control) switch
Select the AFC operation in the fast mode or slow mode.
FAST: incoming sync timing errors are compensated for.
Normally, set this switch to this position.
SLOW: incoming sync timing errors are displayed on the
screen.
This mode is used to monitor the jitter from a
VTR.
O SCAN MODE select switch
Normal scanning or under scanning is achieved by proper
setting of the SCAN MODE select switch. Set to NORMAL
for normal scanning, or to UNDER for viewing a picture
which does not appear in normal scanning. Under scanning
reduces the display size by about 9%.
O V HOLD (vertical hold) control
If the picture rolls vertically, correct it with this control.
O VOLUME control
Turn this control clockwise or counterclockwise to obtain
the desired volume.
O HUE control
This control is effective only for playing tapes of the NTSC
or NTSC 443 system. Use to obtain the most natural skin
tones. Clockwise rotation makes the skin tones more
greenish; counterclockwise rotation makes them more
purplish.
O COLOR control
Adjusts the color intensity of the picture. Clockwise rotation
makes the picture more vivid; counterclockwise rotation
makes it paler.
O BRIGHT (brightness) control
Adjusts the brightness. Normally set this control at the
center detent position.
© PICTURE control
Adjusts the contrast, color intensity and brightness
simultaneously in the proper ratio.
© POWER switch and indicator
To turn the monitor on, depress the POWER switch. The in¬
dicator will light. To turn the monitor off, press the switch
again.
© Input indicators
Illuminate to indicate the input select button pressed.
© Input select buttons
Press to select the program to be monitored.
LINE A: for a signal from the LINE A connectors.
LINE B: for a signal from the LINE B connectors.
VTR: for a signal from the 8 -pin VTR connector.
RGB: for a signal from the R, G and B connectors.
CMPTR: for a signal from the 25-pin CMPTR connector.
© Color system indicators
Indicate the color system of the input video sLgnai.

PVM-1271Q
REAR PANEL
O LINE A O LINE B
Two groups (A and B) of line input connectors for the com¬
posite video and audio signais and their loop-through out¬
put connectors.
To monitor the input signals to these connectors, press the
LINE A or LINE B input select button on the front panel.
VIDEO IN connector (BNC type)
Connect to the video output of a video equipment, such as a
VTR or a color video camera. For a loop-through connection,
connect to the video output of another monitor.
VIDEO OUT connector (BNC type)
Loop-through output of the VIDEO IN connector. Connect to
the video input of a VTR or another monitor.
AUDIO IN jack (mini)
Connect to the audio output of a VTR or to a microphone via
a suitable microphone amplifier. For a loop-through connec¬
tion, connect to the audio output of another monitor.
AUDIO OUT jack (mini)
Loop-through output of the AUDIO IN jack. Connect to the
video input of a VTR or another monitor.
75-ohm termination switch
When only the VIDEO IN connector is used (nothing is con¬
nected to the VIDEO OUT connector), set this switch to ON.
When both the VIDEO IN and VIDEO OUT connectors are us¬
ed together for loop-through connection, set this switch to
OFF.
O VTR connector (8-pin)
Line input for the video and audio signals. When connected
with the 8-pin TV connector of a VTR, the video and audio
playback signal from the VTR can be connected with a
single cable.
To monitor the input signal to this connector, press the VTR
input select button on the front panel.
• For connection, use an optional video cable VMC-3P (3 m,
9 feet), -5P (5 m, 15 feet) or -10P (10 m, 33 feet).
O EXT SYNC (external sync)
IN connector (BNC type)
When this monitor operates on an external sync signal, con¬
nect the reference signal from a sync generator here.
OUT connector (BNC type)
Loop-through output of the EXT SYNC IN connector. Con¬
nect to the external sync input of video equipment to be syn¬
chronized with this monitor.
75-ohm termination switch
When only the EXT SYNC IN connector is used (nothing is
connected to the EXT SYNC OUT connector), set this switch
to ON.
When both the EXT SYNC IN and EXT SYNC OUT connec¬
tors are used together for a loop-through connection, set
this switch to OFF.
O R O G O B O AUDIO (RGB)
Analog RGB and audio input connectors and their loop-
through output connectors.
To monitor the input signal to these connectors, press the
RGB input select button on the front panel.
R/G/B IN conectors (BNC type)
Connect a character generator, microcomputer or video
camera having RGB outputs here.
R/G/B OUT connectors (BNC type)
Loop through output of the R/G/B IN connectors. Connect to
the RGB inputs of another monitor here.
75-ohm termination switch
When only the R/G/B IN connector is used (nothing is con¬
nected to the R/G/B OUT connector), set this switch to ON.
When both the R/G/B IN and R/G/B OUT connectors are used
together for a loop-through connection, set this switch to
OFF.
AUDIO (RGB) IN jack (mini)
Connect the audio output of the equipment connected to
the R/G/B IN connectors here.
AUDIO (RGB) OUT jack (mini)
Loop-through output of the AUDIO (RGB) IN jack.
O CMPTR (computer) connector (25-pin)
Connect with a microcomputer having a digital (TTL level) or
analog RGB video output.
To monitor the input signal to this connector, press the
CMPTR input select button on the front panel.
Color temperature selection
The color temperature of the PVM-1271Q has been preset at
the factory to 9,300°K, and can be changed to 6,500°K.
The color temperature of the PVM-1371QM has been preset
to 6,500°K, and can be changed to 9,300°K.
If the switching of the color temperature is required, consult
your authorized Sony dealer._
8

PVM-1271Q
J
CONNECTING SEVERAL MONITORS
A loop-through connection is convenient for monitoring the
same signal on other monitors. Use the video/audio input
and output connectors of LINE A or LINE B to connect the
monitors. Up to 10 monitors can be connected.
Set the 75-ohm termination switch of the last monitor to ON
and that of the other monitors to OFF.
Microphone
I amp/
r
Microphone
VTR j
I Video camera