sony_ex-2k training manual

7/28/2019 Sony_EX-2K Training Manual

1/27

EX-2K Direct-View LCD Television Chassis

Circuit Description and Troubleshooting Guide

Training Manual

MODELS: KDL22L5000

KDL26L5000

KDL32L5000

KDL32L504

KDL37L5000 Course : CTV-55

KDL32L5000


2/27

CTV-55 i

Power On ........................................................................... 12

PFC Circuit ........................................................................ 12

Standby Power Supply ...................................................... 12

Main Switching Supply....................................................... 12

Protection ...................................................................... 12

Chapter 4 Inverter and Backlighting ............................. 16

Overview ........................................................................ 16

Operation ....................................................................... 16

Chapter 5 Protection and Service Mode ....................... 19

Protection ...................................................................... 19

Self Diagnostics History ..................................................... 21

Clearing the History .............................................................. 21

Status Information.............................................................. 23

Chapter 1 Introduction ..................................................... 1

Introduction ...................................................................... 1

Features .......................................................................... 1

Overall Circuit Description ............................................... 1

A Board .............. .............. ............... .............. ............... ........ 1

Video Processing ....................................................................1

Power Supply ..........................................................................1

Inverter ....................................................................................1

H1 Board .................................................................................2

H2 Board .................................................................................2

Circuit Board Locations........................................................ 2

Chapter 2 Video and Audio Processing Circuits ........... 5

Video Process ................................................................. 5

RF Sources .......................................................................... 5

Composite Video ................................................................. 5

Component Video ................................................................ 5

HDMI Inputs ......................................................................... 5

PC Input ............................................................................... 5

Timing Control (TCON) board.......................................... 6

Troubleshooting ............................................................... 8

No Video .............................................................................. 8

Video Distortions .................................................................. 8

Troubleshooting Flowchart .............................................. 8

Chapter 3 Power Supply ................................................ 12

Overview ........................................................................ 12

Table of Contents


3/27

CTV-55 1

Chapter 1 Introduction

IntroductionThe EX2K chassis is the first release of new models for the 2009 production

year. 4 models are included in this chassis series:

KDL22L5000

KDL26L5000

KDL32L5000 KDL33L540

KDL37L5000

The models are designated as entry-level designs for the Bravia direct-

view LCD televisions. The LCD panel is labeled as 720p with a native

display resolution of 1366 X 768. The television is, however, able to accept

video input resolutions up to 1080p 60HZ via the component, PC or HDMI

inputs.

FeaturesA/V Input Sources

3 HDMI inputs (2 rear, 1 side)

2 composite inputs. (Video 1 shared with component 1 input)

Y/C input on side

2 component inputs (rear only)

PC input (15 pin D-sub)

RF input for ATSC/NTSC tuner

Automatic Contrast Enhancer (ACE): Backlight level changes with

varying scene brightness to increase contrast level and reduce power

consumption.

Bravia Link Compatible: Allows the connection and control of optional

Bravia Link modules such as DVD players and wireless link devices.

24p True Cinema: Allows for 24 frame film content to be viewed in its

original form when connected to devices able to output this format. This

format can only be viewed via the HDMI inputs.

Overall Circuit DescriptionFigure 1-1 illustrates an overall block diagram of the circuits incorporated

into the EX2K chassis models. 4 major circuits are included along with

peripheral circuits and devices. They are described as follows:

A Board

Common among the various models using the EX2K chassis, the A

board contains most of the circuitry used by the television to process the

audio and video signals. The only difference among the various models

is the data which is written and stored in various locations to properly

communicate with the type of LCD panel used.

Audio output is available as L/R analog from RCA jacks or up to 5.1

channel surround sound via an optical jack.

Video Processing

All video sources, regardless of resolution are processed to a resolution of

8-bit RGB at1366 X 768 with a refresh rate of 60HZ. This processed video

exits the A board as Low Voltage Differential Signaling (LVDS) where it is

received by the Timing Control (TCON) board mounted on the LCD panel.

All of the available input sources are mounted directly to the A board.

Power Supply

The G2BE board receives the 120VAC input and generates the requiredstandby and switched voltages for the other circuits in the television.

Inverter

The inverter board, mounted on the left side of the LCD panel (as viewed

from the rear) generates the approximately 1KV of AC voltage to operate

the cold-cathode fluorescent lamps for backlighting of the LCD panel. Its

operating voltage is supplied by a 24VDC source from the G2BE power

supply board.


4/27

Chapter 1 - Introduction

CTV-55 2

H1 Board

Located on the right side of the television (as viewed from the front) this

board contains the power, channel up/down, volume up/down, home

(menu) and input selection buttons.

H2 Board

Located on the lower left corner of the front bezel, this board contains the

power, standby and picture off/timer LED indicators. The infrared receiver

for the remote controller is also located here.

Circuit Board Locations

Figure 1-2 illustrates the locations of the circuit boards with the rear cover

removed. The model in the illustration is the KDL32L5000. Circuit board

location is the same in all models in this series.


5/27


CTV-55 3

FIGURE 1-1

OVERALL BLOCK DIAGRAM

A/V DECODER

VIDEO PROCESS

VIDEO SWITCH

AUDIO PROCESS

AUDIO AMP

TV MICRO

COMPOSITE OR

COMPONENT 1

RF

VIDEO 3

COMPONENT 2

HDMI 1

DVI AUDIO

PC HD15

VIDEO 2

HDMI 2

POWER SUPPLY

SWITCHESLED

IR RX

LCD PANEL

INVERTERTCON

A

G2BEH1 H2

L

R

SIDE INPUTS

ANALOG AUDIO OUT

OPTICAL AUDIO OUT

USB2.0(SERVICE ONLY)

HDMI 3

PC AUDIO


6/27


CTV-55 4

FIGURE 1-2

CIRCUIT BOARD LOCATIONS

A BOARD

G2BE BOARD

TCON

INVERTER

H1

BOARD

H2

BOARD


7/27

CTV-55 5

Chapter 2 Video and Audio Processing Circuits

Video ProcessAll sources of video to be displayed are received and processed by the

A board. All signal sources are also received by IC401 regardless of their

original resolution or format. The function of IC401 is to convert all inputresolutions and formats to 720 progressive frame-rate at 60HZ refresh

rate to conform to the native resolution of the LCD panel.

The properly scaled video exits IC401 as 8-bit parallel RGB formatted digital

video which has been converted to Low Voltage Differential Signaling by

the internal LVDS transmitter inside IC401. The differential signal lines

are sent to the TCON board via a specialized cable with each differential

line carried on twisted wire pairs to minimized external noise interference.

Referring to Figure 2-1, the handling of each format is as follows:

RF SourcesThe dual function tuner is capable of receiving NTSC and ATSC encoded

signals. Although over-the-air NTSC will cease to broadcast in 2009, other

sources of NTSC content (such as VCRs, cable television and satellite

receivers) will remain that use this format as their output.

NTSC RF sources are demodulated inside the tuner and exit as composite

video directly to IC401. ATSC digital sources (8VSB terrestrial and QAM

cable) exit the tuner as differential IF and must be demodulated by IC7101.

The demodulated digital bit stream containing the overhead and payload

data packets is input to IC401 where an internal decoder decompresses

and separates the audio, video and control content.

Composite Video

Composite video input 1 shares the same input jacks as the component

1 input. The composite jack is simply inserted into the Y component input

and is automatically detected as such. If there are any problems with

auto detection of the composite or component source this input can be

changed from auto detect to manual selection by the customer in the user

menu.

Video input 2 is located on the side of the unit and will accept composite

or Y/C (S-video). The default is composite. If a Y/C connector is inserted a

mechanical switch in the Y/C jack will notify IC401 of the input format.

Component Video

There are 2 component inputs at the rear of the unit. As mentioned

previously, component 1 serves as an input for composite video if that is

what is inserted into the Y component jack.

Input resolutions accepted by the component inputs range from 480i

30HZ up to 1080p 60HZ. 1080p 24HZ is not supported by the component

inputs. This resolution is only supported by the HDMI inputs.

HDMI Inputs

There are 3 HDMI inputs on this chassis: HDMI 1 and 3 in the rear and HDMI

2 on the side. The Consumer Electronics Control (CEC) specifications of

the HDMI 1.3 standard is supported giving the customer the ability to

control other devices conforming to this standard that are connected to

the television via the HDMI inputs. Resolutions supported by the HDMI

inputs include all ATSC resolutions including 1080p 24HZ.

PC Input

The PC input is via a VGA 15 pin D-sub connector with RGB analog input.

The following resolutions are supported from a PC with these outputcapabilities:

VGA 640 480 31.5KHZ X 60HZ

SVGA 800 600 37.9KHZ X 60HZ

XGA 1024 768 48.4KHZ X 60HZ

WXGA 1280 768 47.4KHZ X 60HZ

1280 768 47.8KHZ X 60HZ

1360 768 47.7KHZ X 60HZ


8/27

Chapter 2 - Video and Audio Circuit Description

CTV-55 6

Timing Control (TCON) board

The TCON board receives the LVDS signals from the A board. There is an

LVDS receiver located inside the TCON board to convert the RGB data

back to its original 8-bit parallel format.

Based on timing data (also located in the LVDS transmission lines) the

RGB data is allocated to the proper column drivers in sync with the row

drivers to place the RGB data onto the appropriate pixels on the LCD

panel.

The TCON board also contains memory components to store white

balance, gamma and uniformity data specific to each particular LCD

panel. This data is not accessible to the service technician and is why the

current policy is to consider the TCON as part of the LCD panel.


9/27


CTV-55 7

FIGURE 2-1

VIDEO PROCESS BLOCK DIAGRAM

VIDEO 2

COMPOSITE/Y/C

SIDE INPUT

COMPOSITE 1 OR

COMPONENT 1

RF

COMPONENT 2

HDMI 1

HDMI 2

SIDE INPUT

HDMI 3

PC HD15

A

LCD PANEL

TCON

TUNERIC7101

DEMOD

IC401MT5386

ATSCDIFF/IF

NTSC

LVDS

720p/60HZ

USB 2.0

(SERVICE ONLY)


10/27


CTV-55 8

TroubleshootingSince all of the video inputs and processing is located on the A board,

failures causing a loss of video or distortions in the picture need to be

isolated to the A board or the LCD panel. The combining of all video

processing circuitry into 2 major components makes the troubleshootingapproach to seem rather simplistic and in most cases it will be just so.

As anyone who has experience servicing electronic products knows, things

happen in the real world that can cause failures which do not follow the

rules of the academic procedures found in this manual. Always research

the latest service bulletins and/or troubleshooting tips on the Sony service

website before making the service call.

No Video

If a total loss of video occurs (including OSD graphics) the most likely

course of action is to bring a replacement A board to the service location

since the unit is serviced at board-level only. It is unlikely that a loss of

voltage from the power supply is the cause since these voltages are

monitored and the unit will likely experience a protection shutdown event

rather than a no video condition. Although a failure of the backlights to

turn on would certainly cause a no video condition, this too would cause

the unit to shut down and indicate a failure via the self diagnostics feature.

There are cases where the A board can cause a no-backlight issue without

a protection shutdown but you will have brought the A board with you

anyways. If the replacement A board does not resolve the issue and the

backlights are lighting, the LCD panel is the only other likely culprit.

The presence of OSD graphics with a no video condition certainly eliminatesthe LCD panel as the cause and the A board will almost certainly fix the

problem.

Video Distortions

This is, by far, the most difficult failure to troubleshoot due to the many

sources that can cause it. Noise emanating from the power supply, outside

interferences, video process failures and even mechanical problems in

the LCD panel can cause video distortion.The up-side to display devices is that they are the most valuable tool in

determining the source of the problem so long as one knows the basic

theory of how they function. The Appendix section of this training manual

contains a section on basic troubleshooting of LCD panel televisions. The

primary objective when diagnosing no video or distortions in the video is

to eliminate the LCD panel as the cause. Replacement of the LCD panel

requires special authorization and, in some instances, will not be allowed

due to economical reasons.

Troubleshooting FlowchartThe troubleshooting flowchart in Figure 2-2 provides guidance in isolating

a loss of video or distortions in the picture.


11/27


CTV-55 9

FIGURE 2-2

VIDEO FAILURE TROUBLESHOOTING FLOWCHART

Video Failure

Yes

No video or

distorted

video?

OSD graphics

present?

None

Distorted

No

A Board

All inputs?Yes No

YesNo

Unplug LVDS

connector at

TCON while unit

is running. This

may need to be

done more than

once

Any flashes

seen on

screen?

Yes

A Board

No LCD Panel

Backlights

turning on ?

Yes

NoBacklight failure

A Board

Distortion

stationary?A Board

Symentrical?Yes

LCD Panel

Lines single or

multi-colored

Multi-colored

Single Color

A Board

LCD Panel

No


12/27


13/27


CTV-55 11

VIDEO 2

Y/C_COMPOSITE

A

ATSC/NTSC

TUNER

VIDEO 1

COMPOSITE

COMPONENT

VIDEO 3

COMPONENT

HDMI 1

PC

IC801

CLASS D

AUDIO AMP

OPTICAL OUT

L/R AUDIO OUT

HDMI 2

HDMI 3

L

R

AUDIO SOURCE OPTICAL OUTPUT

DIGITAL TUNER

DVD HDMI 5.1

ALL ANALOG INPUTS

NTSC TUNER

SACD VIA HDMI

DVD AUDIO VIA HDMI

5.1 OR 2CH PCM

5.1 OR 2CH PCM

2CH PCM

2CH PCM

NO OUTPUT

NO OUTPUT

OPTICAL OUTPUT TRUTH TABLE

USB2.0

ETHERNET

2CH PCM

N/A

DIGITAL FE

IC7101

DEMOD

I2S

AUDIO

PROCESSOR

ANALOG

IF

IC8101

SWITCH

HDMI 1 AUDIOIC8102

SWITCH

I2S

IC401

ANALOG

IC802

AMP

IF

ATSC

SPDIF

I2S

FIGURE 2-3

AUDIO PROCESS BLOCK DIAGRAM


14/27

CTV-55 12

Chapter 3 Power Supply

OverviewThe power supply used in the EX2K chassis is a traditional switched-mode

type utilizing a standby supply and switched main supply. It provides the

main power for the various circuits in the television.The name of the power supply board will vary depending on the size of

the display. The 22-inch model will incorporate a G board, the 26 and 32-

inch a G2BE board and the 37-inch using a G4 board.

Power On

A power on high command enters CN6201-1 from the A board. The high

enters inverter transistor Q6201 to turn on PH6103. The hot chassis

standby 12V is switched by Q6102 to turn on the main AC relay RY6101.

The standby 12V is also sent to the PFC circuit and to the main switching

supply to turn it on.

PFC Circuit

The Power Factor Control circuit adds additional efficiency to the switch

mode supply by bringing the current and voltage in phase to simulate a

DC resistive load on the AC line. By varying the duty cycle of the pull-

down on the coil (L800) the voltage exiting the PFC circuit is boosted to

generate approximately 395 volts.

Note the AC relay RY6101 has a thermistor (TH6101) across the contacts.

When the unit is not powered on AC voltage flows through the thermistor,is rectified by D6301 and passes through the coil of the PFC circuit. Since

the PFC circuit is not functioning the rectified voltage will be approximately

160VDC and is used by the standby power supply circuits.

Standby Power Supply

As long as AC power is supplied to the unit the standby power supply

will generate 12VDC and 3.3VDC sources. The standby 12VDC is

created on the primary side of the switching transformer T6101 and will

be referenced to hot ground for control of the AC relay, PFC, and main

switching supply.

The standby 3.3VDC is sent to the A board to power up the microprocessor

and other various circuits that must be operational at all times.

Main Switching Supply

When the main switching supply is turned on it provides REG12V to

the A board where many other regulator circuits are used to provide

operating voltages for the various circuits. The UNREG 15V source is

used exclusively by the audio amplifier circuits on the A board. UNREG

24VDC is also output for exclusive use by the inverter board to generate

the high voltage for the fluorescent backlights.

ProtectionCertain circuits in the power supply are monitored for over-voltage, over-

current and over-temperature conditions. If one or more of these detection

lines is activated the main relay RY6101 will turn off along with the PFC

and main switching supply circuits. If any of these circuits are activated the

main switching supply will stop and the standby LED will blink in groups of

3. The following circuits in the power supply are monitored:

REG 12V and UNREG24V OVP: If one or both of these voltage lines

becomes excessive the corresponding zener diode (D6204 or D6205) will

fire and active the latch transistors (Q6202 or Q6203) to ground the power

on command.

PFC OCP and OTP: An over-current or excessive temperature condition in

the PFC circuit will cause a high to be applied at the latch circuit consisting

of Q6104 and Q6105. This performs the same function as the previously

described latch circuit but will occur on the hot ground side of the turn-on

command.


15/27


16/27


17/27

Chapter 3 - Power Supply

CTV-55 15

FIGURE 3-3

VOLTAGE TEST POINTS

CN202

1 LAMP ERROR (NORM LOW)

2 BACKLIGHT ON (3.3V)

3 DIMMER

4 - GROUND

CN4201

TO H1 BOARD

CN4202

TO H2

BOARD

CN802

TO RIGHT

SPEAKER

CN6202

1~4 24V

5~8 - GROUND

CN6101

AC IN

CN801

TO LEFT

SPEAKER

CN6201

1 POWER ON

2 AC_DET

3 STBY 3.3V

4, 5 UNREG 15V

6, 7 UNREG GROUND

8~10 REG GROUND

11`13 REG 12V


18/27

CTV-55 16

Chapter 4 Inverter and Backlighting

OverviewThe Cold Cathode Fluorescent (CCFL) backlights for the LCD panel are

powered by an inverter circuit. This circuit generates the approximately

1KVRMS of high frequency AC power to strike and maintain the ionizationof the gasses inside the fluorescent lamps. The inverter circuits also

function as a ballast circuit to control current levels from initial startup to

steady lighting of the lamps. The inverter circuits also monitor the lamps

to verify that all have been ignited and continuously lit. If one or more of

the lamps fails to light the unit will shut down and blink the standby LED

in groups of 6.

OperationReferring to Figure 4-1, at the time the unit is powered on, the following

string of events occur to light the fluorescent lamps:

IC401 on the A board sends a power on high command to CN6201-1 on the

G2BE board. This engages the main relay and starts the main switching

supply. 24VDC is applied to CN001 on the inverter board. During this time

the microprocessor inside IC401 is performing initialization routines and

turning on regulator circuits located on the A board.

After approximately 5 seconds, a high command (3.3V) is applied from

CN202-2 on the A board to CN001 on the inverter. This starts the oscillators

and drive circuits to begin the lighting of the fluorescent lamps. The lamps

are struck with approximately 2 to 3 times their operating voltage of 1KV

AC to begin ionization of the gasses within the lamps. Once the lampsbegin to draw current, the inverters function as a ballast circuit to maintain

control of the current.

If one or more of the lamps fail to ignite, or if either of the inverter circuits

fails to operate, an error detection circuit located on the inverter board will

send a high command to CN202-1 on the A board. The unit will shut down

and the standby LED will blink in groups of 6.

TroubleshootingMost backlight failures will cause the unit to shutdown and generate a

6-blink error indication. Since an inverter failure or defective fluorescent

lamp can cause either symptom it is import to know whether the backlightshave turned on when the shutdown and error indication occurs. This is

easily checked when the technician is present during the failure but a

bit tricky when attempting to triage the repair by having the customer

determine if the backlights are turning on,

In most instances it is relatively easy for a technician with experience to

check and see if the backlights are turning on. Ambient lighting conditions

and a failure of the customer to comprehend backlighting may make this

difficult over the phone. In these cases it is sometimes helpful to ask the

customer if the screen appears to go darker when the unit shuts down

since it is easier to observe the backlights when they turn off rather thanwhen they first start because the sound of the main relay turning off can

be a clue as to when to observe the screen for a change in brightness.

The point here is to try and determine whether the backlights are turning

on before the unit shuts down. If they turn on before the shutdown the LCD

panel will most likely require replacement. The troubleshooting flowchart

in Figure 4-2 will assist in isolating the cause of a 6-blink shutdown.

IMPORTANT: If a unit is found to be turning on with no backlights, yet it

is not shutting down (power LED remains steady green), do not replace

the LCD panel or inverter board. There cannot be a defective backlight

or inverter board without a 6-blink shutdown.

Anytime the backlights do not turn on and the unit does not shut down it

is usually caused by the microprocessor. A failure event occurred during

initialization and the microprocessor hangs. One of the last output lines

to go active is the backlight on command to turn on the inverter. This is why

the backlights never come on and there is no self-diagnostics shutdown.


19/27


20/27


21/27


22/27

Chapter 5 - Protection and Service Mode

CTV-55 20

IC801

AUDIO

AMP

BACKLIGHT ERROR 6X

REG 12V 11

CN201

1INV_ERR

CN202

IC401

5X

A

Q401SWITCH

TCON

12V

TCON POWER ERROR

LOW B+ 3X

IC201

5V

IC202

1V

IC2093.3VDEM

IC2081.8V

DDR

IC204

3.3V

IC2071.25V

IC210

1.2V

IC206

2.5V

IC2039V

IC211TU5V

D203A

D208A

D208B

D209B

D207

D203B

D209A

D206

D214A

D214B

Q211

V_DROP_DET

SPEAKER PROTECT 8X

FIGURE 5-1

PROTECTION BLOCK DIAGRAM


23/27


CTV-55 21

FIGURE 5-2

SERVICE MODE START PAGE

Service ModeThe service mode is entered in the traditional method of pressing the

DISPLAY, 5, VOL+ and POWER keys on the remote commander,

in sequence, while the unit is powered off. If the sequence is properly

executed the service mode opening page should display as illustrated in

Figure 5-2.

Note that several items appear on the page. Each item can be selected by

using the UP and DOWN feature of the joystick on the remote or with the

volume and channel buttons on the top of the television. Most of the items

in the list are set at factory default values and should not be changed. The

only 2 items of concern to the service technician are the Self Diagnostics

History and Status Information lines.

Self Diagnostics History

The self-diagnostics history page can be selected in the service modeas illustrated in Figure 5-3. This page can also be directly accessed by

pressing DISPLAY, 5, VOL - and POWER on the remote commander

when the unit is turned off.

In this page a running count is displayed of any protect shutdown events

that have occurred. This is particularly useful for determining the cause of

intermittent problems. The last event registered will be highlighted in red

text.

Clearing the History

The diagnostics history count should always be cleared once the repairhas been completed to leave a clean page for any future events that may

occur. This is performed by pressing the 8 followed by the 0 key on the

remote commander while viewing the page. All diagnostics event counts

should reset to zero.


24/27


CTV-55 22

FIGURE 5-3

SELF-DIAGNOSTICS PAGE

LAST ERROR

RECEIVED

APPEARS IN RED

ERROR COUNT

RESET BY

PRESSING 8

FOLLOWED BY 0

ON REMOTE

COMMANDER


25/27


CTV-55 23

FIGURE 5-4

TUNING STATUS PAGE

Status Information

By selecting this item the page illustrated in Figure 5-4 will appear. This

feature is particularly useful for troubleshooting complaints of picture quality

issues from antenna or cable sources. Important information such as the

type of input selected on the television (cable or antennal), the physical

channel, operating frequency and modulation type are displayed.

Although Automatic Gain Control (AGC) and Signal-to-Noise Ratio

numbers are displayed it is best to use the signal level disgnaostics in the

customer menu as illustrated in Figure 5-5.

When viewing the customer signal diagnostics a signal strength meter

along with an error count column is displayed. There should be no errors

displayed and the signal level meter should read higher than 30%. The

AGC level is not reliable. The SNR level is important and should display

the following minimum values for reliable picture quality:

8VSB: 16 or greater

64QAM: 24 or greater

256 QAM: 28 or greater


26/27


CTV-55 24

FIGURE 5-5

CUSTOMER TUNING STATUS PAGE


27/27

and i.Link are trademarks of Sony Electronics

2009 Sony Electronics, Inc.

SEL Service Company

16530 Vill Esprillo

National Training Dept. MZ3215

San Diego, CA 92127

Reproduction in whole or part without written permission is prohibited. All rights reserved

CTV550309 7/20/09

sony_ex-2k training manual

Documents