DOWNLOAD Sony SDM-N50 (serv.man2) Service Manual ↓ Size: 4.38 MB | Pages: 62 in PDF or view online for FREE

– 5 –

The AC leakage from any exposed metal part to earth ground

and from all exposed metal parts to any exposed metal part hav-

ing 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 instruments.

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 voltmeter. The “limit” indica-

tion 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 VOMs that are suitable. Nearly all

battery operated digital multimeters that have a 2 V AC

range are suitable.  (See Fig. A)

¡

¡

After correcting the original service problem, perform the fol-

lowing safety checks before releasing the set to the customer:

1. Check the area of your repair for unsoldered or poorly-sol-

dered 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, particularly tran-

sistors, 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 replacement.

6. Check the line cords for cracks and abrasion. Recommend

the replacement of any such line cord to the customer.

7. Check the B+ and HV to see if they are specified values.

Make sure your instruments are accurate; be suspicious of

your HV meter if sets always have low HV.

8. Check the antenna terminals, metal trim, “metallized”

knobs, screws, and all other exposed metal parts for AC

Leakage. Check leakage as described below.

Fig. A. Using an AC voltmeter to check AC leakage.

1.5 k

Ω

0.15 

µ

F

AC
Voltmeter
(0.75 V)

To Exposed Metal
Parts on Set

Earth Ground

– 6 –

.................................................................. 1-1

2-1.

U Board Removal ................................................ 2-1

2-2.

Base Assembly Removal ...................................... 2-1

2-3.

B Board Removal ................................................ 2-2

2-4.

H Board Removal ................................................. 2-3

2-5.

LCD Module (TFT) Removal .............................. 2-3

2-6.

A Board Removal ................................................. 2-4

2-7.

G Board Removal ................................................. 2-4

...................................................... 3-1

4-1.

Block Diagrams .................................................... 4-1

4-2.

Circuit Boards Location ...................................... 4-7

4-3.

Schematic Diagrams and Printed Wiring Boards ... 4-8

(1) Schematic Diagrams of A (P1-P3) Board ............ 4-9

(2) Schematic Diagrams of B (P1-P3) Board ............ 4-23

(3) Schematic Diagrams of H Board .......................... 4-31

(4) Schematic Diagrams of U Board .......................... 4-35

(5) Schematic Diagrams of G (P1-P2) Board ............ 4-43

4-4. Semiconductors ................................................... 4-47

5-1.

Display ................................................................. 5-1

5-2.

Chassis ................................................................. 5-2

5-3.

Packing Materials ................................................ 5-3

............................ 6-1

1-1

4

• Use the supplied power cord. If you use a different power cord, 

be sure that it is compatible with your local power supply.
For the customers in the U.S.A.
If you do not use the appropriate cord, this monitor will not 
conform to mandatory FCC standards.
For the customers in the UK
If you use the monitor in the UK, please use the appropriate UK 
power cord.

Do not install or leave the monitor:
• In places subject to extreme temperatures, for example near a 

radiator, heating vent, or in direct sunlight. Subjecting the 
monitor to extreme temperatures, such as in an automobile 
parked in direct sunlight or near a heating vent, could cause 
deformations of the casing or malfunctions.

• In places subject to mechanical vibration or shock.
• Near any equipment that generates a strong magnetic field, 

such as a TV or various other household appliances.

• In places subject to inordinate amounts of dust, dirt, or sand, for 

example near an open window or an outdoor exit. If setting up 
temporarily in an outdoor environment, be sure to take 
adequate precautions against airborne dust and dirt. Otherwise 
irreparable malfunctions could occur.

• Do not leave the LCD screen facing the sun as it can damage 

the LCD screen. Take care when you place the monitor by a 
window.

• Do not push on or scratch the LCD screen. Do not place a heavy 

object on the LCD screen. This may cause the screen to lose 
uniformity or cause LCD panel malfunctions.

• If the monitor is used in a cold place, a residual image may 

appear on the screen. This is not a malfunction. The screen 
returns to normal as the temperature rises to a normal operating 
level.

• If a still picture is displayed for a long time, a residual image 

may appear for a while. The residual image will eventually 
disappear.

• The LCD panel becomes warm during operation. This is not a 

malfunction.

• Be sure to unplug the power cord from the power outlet before 

cleaning your monitor.

• Clean the LCD screen with a soft cloth. If you use a glass 

cleaning liquid, do not use any type of cleaner containing an 
anti-static solution or similar additive as this may scratch the 
LCD screen’s coating.

• Clean the cabinet, panel, and controls with a soft cloth lightly 

moistened with a mild detergent solution. Do not use any type 
of abrasive pad, scouring powder, or solvent, such as alcohol or 
benzine.

• Do not rub, touch, or tap the surface of the screen with sharp or 

abrasive items such as a ballpoint pen or screwdriver. This type 
of contact may result in a scratched picture tube.

• Note that material deterioration or LCD screen coating 

degradation may occur if the monitor is exposed to volatile 
solvents such as insecticide, or if prolonged contact is 
maintained with rubber or vinyl materials.

• Disconnect all cables from the monitor when transporting.

When you transport this display, grasp the support and base 
sections of the display stand firmly with both hands. Also use 
both hands when carrying the media engine. If you drop the 
monitor, you may be injured or the monitor may be damaged.

• When you transport this monitor for repair or shipment, use the 

original carton and packing materials.

A specially designed fluorescent tube is installed as the lighting 
apparatus for this monitor. If the screen becomes dark, unstable, 
or does not turn on, replace the fluorescent tube with a new one. 
Consult your Sony dealer when replacing the fluorescent tube. 

•

•

The equipment should be installed near an easily accessible 
outlet.

Example of plug types

for 100 to 120 V AC

for 200 to 240 V AC

for 240 V AC only

5

This display can be adjusted within the angles shown below.

To adjust the angles, grasp the lower sides of the LCD panel with 
both hands as shown below. Tilt the LCD panel adequately 
backward, then lift the LCD panel upward to the desired screen 
height, then adjust the screen tilt as desired. When adjusting the 
screen height and tilt, proceed slowly and carefully, being sure not 
to hit the LCD panel against the desk or the base of the display 
stand.

This display is designed so that you can set it up at a comfortable 
viewing angle. Adjust the viewing angle of your display 
according to the height of the desk and chair, and so that light is 
not reflected from the screen to your eyes.

This monitor has a built-in stereo speaker in base of the display 
stand. 
We recommend that you position the LCD panel slightly away 
from the display stand. High tones from the speaker may be 
muffled if the LCD panel is positioned immediately on top of the 
stand. Be careful not to drop any metal object into the speaker's 
vents as the speakers generate a magnetic field. Also, this 
magnetic field may affect data stored on magnetic tapes and discs. 
Be sure to keep magnetic recording equipment, tapes, and floppy 
discs away from the speaker’s opening. 
A duct is provided on the rear part of the display stand to boost the 
bass. Be sure not to block the duct with paper or other objects to 
ensure clear sound.

90˚

40˚

50˚

50˚

m

Ducts

Keep the LCD panel 
slightly away from 
the base.

Speaker

1-2

6

See the pages in parentheses for further details.

1

1 

This switch turns the display on and off.
The indicator lights up in green when the monitor is turned on. 
The indicator flashes in green and orange when the monitor is 
in low power consumption mode, and lights up in orange 
when the monitor is in power saving mode.

2

These sensors measure the brightness of the surrounding area 
and detect when a user becomes present in front of the screen. 
Be sure not to cover the sensor with papers, etc.

3

This button displays the main menu.

4

6 

This button displays the CONTRAST menu.

5

8 

This button displays the BRITGHTNESS menu.

6

2 

M

m

These buttons display the VOLUME menu and function as 
the 

M(+)/m(–) buttons when selecting the menu items and 

making adjustments.

7

This button selects the INPUT 1 or INPUT 2 (HD15 (RGB) 
connectors) video input signal. The input signal and 
corresponding input indicator change each time you press this 
button. 
This button also functions as the OK button when displaying 
the menu on the screen.

8

This outputs the audio signals as sound.

9

These are used to boost the bass sound from the speaker.

0

This connector inputs signals from the media engine when the 
display and the media engine are connected with a system 
connecting cable.

qa

This jack outputs audio signals to the headphones.

MENU

INPUT

OK

1
2

SYSTEM CONNECTER

7

qs

This jack inputs audio signals when connecting to the audio 
output jack of the computer or other audio equipment.

qd

This connector outputs signals to the display when the display 
and the media engine are connected with a system connecting 
cable.

qf

This connector inputs RGB video signals (0.700 Vp-p, 
positive) and SYNC signals.

* DDC (Display Data Channel) is a standard of VESA.

qg

This connector inputs RGB video signals (0.700 Vp-p, 
positive) and SYNC signals. The pin assignment is the same 
as qf.

qh

This connector provides AC power to the monitor.

qj

This switch turns the monitor on and off. When the AC power 
switch is turned on, the display automatically turns on.

qk

This indicator lights up in green when the media engine is 
turned on. The indicator lights up in red when the display is 
turned off with the media engine on. The indicator lights up in 
orange when the monitor is in the power saving mode.

ql

This stand is used to install the media engine vertically.

Be sure to install the media engine vertically shown as left. Installing the 
media engine lying flat may block ventilation, and may cause a 
malfunction. 

1

Red

2

Green
(Sync on Green)

3

Blue

4

ID (Ground)

5

DDC Ground*

6

Red Ground

7

Green Ground

8

Blue Ground

9

DDC + 5V*

10

Ground

11

ID (Ground)

12

Bi-Directional Data (SDA)*

13

H. Sync

14

V. Sync

15

Data Clock (SCL)*

SYSTEM CONNECTER

(TO DISPLAY)

INPUT 1

INPUT 2

AUDIO IN

5 4

3 2 1

6

7

8

9

10

11

12

13

14

15