Thursday, October 30, 2014

PANASONIC CT-20SX11E - CT-20SX11CE – Color TV - HOW TO ENTER SERVICE MODE


CT-20SX11E - CT-20SX11CE – Color TV - SERVICE MODE _ Panasonic
Entering Service Mode (Back-Open Method)
1. While the Receiver is ON and operating in Normal Mode, momentarily short test point FA1 (TP8) to Cold Ground ( ) FA2 (TP3) A-Board.  (The Receiver enters the Aging Mode.)
Yellow letters “CHK” appear in the upper left corner of the CRT.  (The Volume Up/Down will adjust rapidly).
2. Simultaneously press the Action and the Volume Up buttons on the Receiver Control Panel.
The Receiver enters the Service Mode.
The letter in “CHK” turns red. (The Volume Up/Down will adjust normally). (All customer controls are set to nominal level)
Using its remote control
Select SET-UP icon and select CABLE mode.
Select TIMER icon and set SLEEP time for 30 Min.
Press ACTION button twice to exit menus.
Tune to the Channel 124.
Adjust VOLUME to minimum (0).
Press the VOL button (decrease) on Receiver. Red “CHK” appears in upper corner.
To toggle between Aging and Service modes:
While the “CHK” is displayed on the left top corner of the CRT, pressing the Action and the Volume Up buttons on the Receiver simultaneously will toggle between the modes. Red “CHK” for Service and yellow “CHK” for Aging.
Press the Power Button on the Remote Control to select one of six Service Adjustment Modes.
B= Service VCJ SUB-DATA ADJUSTEMENT.
C= Service VCJ CUT-OFF ADJUSTMENT.
S= Service OPTIONS (PIP and CLOCK) ADJUSTMENT.
M= Service MTS ADJUSTMENTS.
X = Service COMB FILTER ADJUSTMENT.
“CHK” = Normal operation of CHANNEL Up / Dn and VOLUME  L / R.
How to Exit the Service Mode
Press the Action and the Power buttons on the Receiver simultaneously for at least 2 seconds.
THE RECEIVER EXITS SERVICE MODE.
The Receiver momentarily shuts off; then comes back on tuned to channel 3 with a preset level of sound.  Any programmed channels, channels caption data and some others user defined settings will be erased.
Service Mode Menu Adjustments.
An address Menu appears in the right hand corner of the screen
NB: Always Exit the Service Mode Following Adjustments.
Press the Power Button on the Remote Control to select the Service Adjustment
For Adjustments
Press Channel Up/Down on the Remote Control to select one of the available Service Adjustments. [Write Down the original value set for each address before modifying anything. It is easy to erroneously adjust the wrong item]
Press Volume Up/Down on the Remote Control to adjust the level of the selected Service Adjustment.
To Check colour Purity
Press the Recall Button on the Remote Control when in Service Mode (red “CHK” is displayed) to enter the Purity Field Check Mode.

Tuesday, October 28, 2014

HOW TO DISASSEMBLE - AOC LE32H1581 and AOC-LE42H1581 - LED LCD TV


AOC LE-LE32H1581 
AOC LED LCD TV - LE032H1581 & LE421581_Disassemble Procedure
Remove the screws to remove STAND BASE
Remove the screws to remove REAR COVER
Remove the screws to remove BRACKET_STAND.
Remove the screws to remove DECO, BKT, MAIN BOARD and POWER BOARD
Remove the screws to remove BKT and separate PANEL and BEZEL.
Remove the screws to remove KEY BOARD and LED BOARD
AOC LE-42H1581
Remove the screws to remove STAND, BASE and REAR_COVER.
Remove the screws to remove SPEAKERS, AC COVER and BKT
Remove the screws to remove MAIN BOARD, POWER BOARD and CONVERTER BOARD.
Remove the screws to remove LED BOARD and BKT and separate the BEZEL and PANEL.
Remove the screws to remove IR BOARD and KEY BOARD


Monday, October 27, 2014

SONY KDL-32EX725/40EX725/55EX725 – HOW TO REMOVE and ATTACH THE STAND

SONY KDL-32EX725/KDL-40EX725/KDL-55EX725

KDL-32EX725/40EX725/55EX725 – HOW TO REMOVE and ATTACH THE STAND _ STAND ASSEMBLY PARTS & SCREW SIZES
Table-Top Stand Fixing screws for Table-Top Stand (M5 × 16) (3)
Assembling screws for Table-Top Stand (M6 × 14) (4) (for KDL-55EX72x
Assembling screws for Table-Top Stand (M6 × 14) (3) (for KDL-40/32EX72x
TABLE-TOP STAND ASSEMBLY REMOVAL
Remove 3 screws from Table-Top Stand Assembly. 
Lift up TV set to detach from Table-Top Stand Assembly.
Gently place the LCD TV set face down onto a soft cloth.
STAND PARTS
[1]. >  4-267-490-01 >>  STAND, HEAD(M9) - (KDL-32EX725 ONLY)
[2]. >  4-267-497-01  STAND, HEAD(ML9) -  (KDL-40EX725/55EX725 ONLY)
[2] > 4-259-177-02  NECK (M9) - (KDL-32EX725 ONLY)
[2]. >  4-259-180-02  NECK (ML9) - (KDL-40EX725 ONLY)
[2]. >  4-259-186-02  NECK (LL9) - (KDL-55EX725 ONLY)
[3] > 4-267-555-01  STAND, BASE(M2) - (KDL-32EX725 ONLY)
[3]. > 4-267-560-01  STAND, BASE(ML2) - (KDL-40EX725 ONLY)
[3] > 4-267-566-01  STAND, BASE(LL2) - (KDL-55EX725 ONLY)
[4]. > 4-259-541-01  USER SCREW ST - (SCREWS TO ATTACH HEAD STAND AND BASE STAND TO NECK)
[5]. > 2-580-608-01  SCREW, +PSW M5X16 - (SCREWS TO ATTACH TABLE-TOP STAND TO LCD TV) (For product protection and safety reasons, Sony strongly recommends that you use the screws provided with the TV).
CAUTION: These screws cannot be used to secure the TV to the Wall Mount Brackets.
2-580-608-01  SCREW, +PSW M5X16 - (SCREWS TO ATTACH TABLE-TOP STAND TO LCD TV)

Monday, October 20, 2014

HOW TO ENTER SERVICE MODE AND ADJUST DATA VALUES TO PHILIPS LCD TVS


Service Modes
Service Default mode (SDM) and Service Alignment Mode (SAM) offers several features for the service technician, while the Customer Service Mode (CSM) is used for communication between the call centre and the customer.  This chassis also offers the option of using ComPair, a hardware interface between a computer and the TV chassis. It offers the abilities of structured troubleshooting, error code reading, and software version readout for all chassis.  Minimum requirements for ComPair: a Pentium processor, a Windows OS, and a CD-ROM drive.
Service Default Mode (SDM)
Purpose
* To create a predefined setting for measurements to be made.
* To override software protections.
* To start the blinking LED procedure.
* To inspect the error buffer.
* To check the life timer
Specifications
# Tuning frequency: 475.25 MHz
# Color system: PAL-BG.
# All picture settings at 50%(brightness, color contrast, hue).
# Bass, treble and balance at 50 %; volume at 25 %.
# All service-unfriendly modes (if present) are disabled. The service unfriendly modes are:
> Timer / Sleep timer.
> Child / parental lock.
> Blue mute.
> Hotel / hospital mode.
> Auto shut off (when no “IDENT” video signal is received for 15 minutes).
> Skipping of non-favorite presets / channels.
> Auto-storage of personal presets.
> Auto user menu time-out.
> Auto Volume Leveling (AVL).
How to enter
To enter SDM, use one of the following methods:
 Press the following key sequence on the remote control transmitter: “062596” directly followed by the MENU button (do not allow the display to time out between entries while keying the sequence).
 Short "Service" jumpers on the small signal board during cold start and apply mains (see Figure "Service jumpers").  Then press the mains button (remove the short after startup).
Caution: Entering SDM by shorting "Service" jumpers will override the +5V-protection. Do this only for a short period.  When doing this, the service-technician must know exactly what he is doing, as it could damage the television set.
SERVICE JUMPERS
After entering SDM, the following screen is visible, with SDM in the upper right corner of the screen to indicate that the television is in Service Default Mode.
How to navigate
Use one of the following methods:
 * When you press the MENU button on the remote control, the set will switch on the normal user menu in the SDM mode.
* On the TV, press and hold the VOLUME DOWN and press the CHANNEL DOWN for a few seconds, to switch from SDM to SAM and reverse.
How to Exit
Switch the set to STANDBY by pressing the mains button on the remote control transmitter or the television set.  If you turn the television set off by removing the mains (i.e., unplugging the television) without using the mains button, the television set will remain in SDM when mains is re-applied, and the error buffer is not cleared.
Service Alignment Mode (SAM)
Purpose
• To change option settings.
• To display / clear the error code buffer.
• To perform alignments.
Specifications
• Operation hours counter (maximum five digits displayed).
• Software version, Error codes, and Option settings display.
• Error buffer clearing.
• Option settings.
• AKB switching.
• Software alignments (Tuner, White Tone, Geometry & Audio).
• NVM Editor.
• ComPair Mode switching.
How to Enter
To enter SAM, use one of the following methods:
• Press the following key sequence on the remote control transmitter: “062596" directly followed by the OSD/STATUS button (do not allow the display to time out between entries while keying the sequence).
• Or via ComPair.
After entering SAM, the following screen is visible, with SAM in the upper right corner of the screen to indicate that the television is in Service Alignment Mode.
Menu Explanation
1.LLLLL. This represents the run timer. The run timer counts normal operation hours, but does not count standby hours.
2.AAABCD-X.Y. This is the software identification of the main microprocessor:
>A= the project name (LC41).
>B= the region: E= Europe, A= Asia Pacific, U= NAFTA, L= LATAM.
>C= the software diversity:
• Europe: T= 1 page TXT, F= Full TXT, V= Voice control.
• LATAM and NAFTA: N= Stereo non-dBx, S=Stereo dBx.
• Asian Pacific: T= TXT, N= non-TXT, C= NTSC.
• ALL regions: M= mono, D= DVD, Q= Mk2.
>D= the language cluster number.
>X= the main software version number (updated with a major change that is incompatible with previous versions).
>Y= the sub software version number (updated with a minor change that is compatible with previous versions).
>EEEEEE= the scaler sw cluster
>F= the main sw version no.
>GG= the sub-version no.
3.SAM. Indication of the Service Alignment Mode.
4.Error Buffer. Shows all errors detected since the last time the buffer was erased. Five errors possible.
5.Option Bytes. Used to set the option bytes. See “Options” in the Alignments section for a detailed description. Seven codes are possible.
6.Clear. Erases the contents of the error buffer. Select the CLEAR menu item and press the MENU RIGHT key. The content of the error buffer is cleared.
7.Options. Used to set the option bits. See “Options” in the Alignments section for a detailed description.
8.Tuner.Used to align the tuner. See “Tuner” in the Alignments section for a detailed description.
9.White Tone. Used to align the white tone. See “White Tone” in the Alignments section for a detailed description.
10.Audio. No audio alignment is necessary for this television set.
11.NVM Editor. Can be used to change the NVM data in the television set. See table “NVM data” further on.
12.SC NVM Editor.Can be used to edit Scaler NVM.
13.ComPaIr. Can be used to switch on the television to In System Programming (ISP) mode, for software uploading via ComPair.
Caution: When this mode is selected without compare connected, the TV will be blocked. Remove the AC power to reset the TV
How to Navigate
• In SAM, select menu items with the MENU UP/DOWN keys on the remote control transmitter. The selected item will be highlighted. When not all menu items fit on the screen, use the MENU UP/DOWN keys to display the next / previous menu items.
• With the MENU LEFT/RIGHT keys, it is possible to:
> Activate the selected menu item.
> Change the value of the selected menu item.
> Activate the selected submenu.
• In SAM, when you press the MENU button twice, the set will switch to the normal user menus (with the SAM mode still active in the background). To return to the SAM menu press the MENU or STATUS/EXIT button.
• When you press the MENU key in while in a submenu, you will return to the previous menu.
How to Store SAM settings
To store the settings changed in SAM mode, leave the top level SAM menu by using the POWER button on the remote control transmitter or the television set.
How to Exit
Switch the set to STANDBY by pressing the mains button on the remote control transmitter or the television set.  If you turn the television set “off” by removing the mains (i.e., unplugging the television) without using the mains button, the television set will remain in SAM when mains is re-applied, and the error buffer is not cleared.
Customer Service Mode (CSM)
Purpose
The Customer Service Mode shows error codes and information on the TV’s operation settings. The call centre can instruct the customer (by telephone) to enter CSM in order to identify the status of the set. This helps the call centre to diagnose problems and failures in the TV set before making a service call.
The CSM is a read-only mode; therefore, modifications are not possible in this mode.
How to Enter
To enter CSM, press the following key sequence on the remote control transmitter: “123654” (do not allow the display to time out between entries while keying the sequence).  Upon entering the Customer Service Mode, the following screen will appear:
Menu Explanation
1. Indication of the decimal value of the operation hours counter, Software identification of the main microprocessor
(see "Service Default or Alignment Mode" for an explanation), and the service mode (CSM= Customer Service Mode).
2. Displays the last five errors detected in the error code buffer.
3. Displays the option bytes.
4. Displays the type number version of the set.
5. Reserved item for P3C call centers (AKBS stands for
Advanced Knowledge Base System).
6. Indicates the television is receiving an "IDENT" signal on the selected source. If no "IDENT" signal is detected, the display will read "NOT TUNED"
7. Displays the detected Colour system (e.g. PAL/NTSC).
8. Displays the detected Audio (e.g. stereo/mono).
9. Displays the picture setting information.
10. Displays the sound setting information.
How to Exit
To exit CSM, use one of the following methods:
• Press the MENU, STATUS/EXIT, or POWER button on the remote control transmitter.
• Press the POWER button on the television set.
Problems and Solving Tips Related to CSM
Picture Problems
Note: The problems described below are all related to the TV settings. The procedures used to change the value (or status) of the different settings are described.
Picture too Dark or too Bright
If:
• The picture improves when you press the AUTO PICTURE button on the remote control transmitter, or
• The picture improves when you enter the Customer Service Mode,
Then:
1. Press the AUTO PICTURE button on the remote control transmitter repeatedly (if necessary) to choose PERSONAL picture mode.
2. Press the MENU button on the remote control transmitter. This brings up the normal user menu.
3. In the normal user menu, use the MENU UP/DOWN keys to highlight the PICTURE sub menu.
4. Press the MENU LEFT/RIGHT keys to enter the PICTURE sub menu.
5. Use the MENU UP/DOWN keys (if necessary) to select BRIGHTNESS.
6. Press the MENU LEFT/RIGHT keys to increase or decrease the BRIGHTNESS value.
7. Use the MENU UP/DOWN keys to select PICTURE.
8. Press the MENU LEFT/RIGHT keys to increase or decrease the PICTURE value.
9. Press the MENU button on the remote control transmitter twice to exit the user menu.
10. The new PERSONAL preference values are automatically stored.
White Line around Picture Elements and Text
If:
The picture improves after you have pressed the AUTO PICTURE button on the remote control transmitter,
Then:
1. Press the AUTO PICTURE button on the remote control transmitter repeatedly (if necessary) to choose PERSONAL picture mode.
2. Press the MENU button on the remote control transmitter. This brings up the normal user menu.
3. In the normal user menu, use the MENU UP/DOWN keys to highlight the PICTURE sub menu.
4. Press the MENU LEFT/RIGHT keys to enter the PICTURE sub menu.
5. Use the MENU UP/DOWN keys to select SHARPNESS.
6. Press the MENU LEFT key to decrease the SHARPNESS value.
7. Press the MENU button on the remote control transmitter twice to exit the user menu.
8. The new PERSONAL preference value is automatically stored.
Snowy Picture
Check CSM line 6. If this line reads “Not Tuned”, check the following:
• Antenna not connected. Connect the antenna.
• No antenna signal or bad antenna signal. Connect a proper antenna signal.
• The tuner is faulty (in this case line 2, the Error Buffer line, will contain error number 10). Check the tuner and replace/ repair the tuner if necessary.
Black and White Picture
If:
• The picture improves after you have pressed the AUTO PICTURE button on the remote control transmitter,
Then:
1. Press the AUTO PICTURE button on the remote control transmitter repeatedly (if necessary) to choose PERSONAL picture mode.
2. Press the MENU button on the remote control transmitter. This brings up the normal user menu.
3. In the normal user menu, use the MENU UP/DOWN keys to highlight the PICTURE sub menu.
4. Press the MENU LEFT/RIGHT keys to enter the PICTURE sub menu.
5. Use the MENU UP/DOWN keys to select COLOUR.
6. Press the MENU RIGHT key to increase the COLOUR value.
7. Press the MENU button on the remote control transmitter twice to exit the user menu.
8. The new PERSONAL preference value is automatically stored.
Menu Text not Sharp Enough
If:
• The picture improves after you have pressed the AUTO PICTURE button on the remote control transmitter,
Then:
1. Press the AUTO PICTURE button on the remote control transmitter repeatedly (if necessary) to choose PERSONAL picture mode.
2. Press the MENU button on the remote control transmitter.  This brings up the normal user menu.
3. In the normal user menu, use the MENU UP/DOWN keys to highlight the PICTURE sub menu.
4. Press the MENU LEFT/RIGHT keys to enter the PICTURE sub menu.
5. Use the MENU UP/DOWN keys to select PICTURE.
6. Press the MENU LEFT key to decrease the PICTURE value.
7. Press the MENU button on the remote control transmitter twice to exit the user menu.
8. The new PERSONAL preference value is automatically stored.



Saturday, October 18, 2014

MITSUBISHI WS-A48 - VS-A50 - WS-A55 - WS-A65 PTV – HOW TO ADJUST CONVERGENCE


HOW TO ADJUST CONVERGENCE _ MITSUBISHI WS-A48 - VS-A50 - WS-A55 - WS-A65 Projection TV 
Convergence Adjustment Mode
Press MENU-2-2-5-9
When the Convergence Mode is activated, the display at the right appears on a Green Crosshatch.
Selecting the HD or SD Mode
1. Select the Signal Source before entering the Convergence Mode, either an NTSC or HD source.
2. Enter the Convergence Mode (MENU-2-2-5-9)
* If the signal source is NTSC, the SD mode is activated.
* If the signal source is HD 1080i, the HD mode is activated.
3. Activating the HD mode when no HD signal is available.
* Activate the Factory Option Menu (MENU-2-2-7-0)
* Use the “Adjust” keys to select “DTV Port” and press “Enter” to change the setting to “1080i”.  Sequence = “Auto”-”480i”-480-p”-”1080i”.
Ignore any loss of sync while changing modes.
 Exit the Option Menu (Press “MENU” twice).
* Select the DTV Inputs as the signal source (INPUT button).
* Activate the Convergence Mode ... the Convergence mode will be in the HD mode and the internal crosshatch is displayed.

After adjusting Convergence, be sure to set the DTV Port back to AUTO.
• Select an analog input as the signal source (INPUT button).
• Activate the Option Menu (MENU-2-2-7-0).
• Use the “Adjust” keys to select “DTV Port and press “Enter” to change the setting from “1080i” to “AUTO”.
• Exit the Option Menu (Press MENU twice).

Convergence Mode Functions
In the Convergence Mode there are three main Functions (Categories).
* Pressing “6” activates CONV MISC
* Pressing “5” activates COARSE CONV
* Pressing “4” activates FINE CONV
CONV MISC (Press 6)
This mode is used to preset data values controlling the Convergence Generator, and to perform the HV Regulation adjustment.
Use the VIDEO button to select an item.
Use the ADJUST buttons to change data.
Note: When Item “1 HVOL” is selected the screen goes black except for the data display.  This occurs since a black screen is required when making the HV Regulation adjustment.
COARSE CONV (Press 5)
There are four Sub Functions in the Coarse mode, COARSE GREEN, COARSE RED, COARSE BLUE and DF.
* COARSE GREEN .... used to make Coarse Raster Geometry Adjustments.
* COARSE RED ... used to make Coarse Red Convergence Adjustments.
* COARSE BLUE ... used to make Coarse Blue Convergence Adjustments.
* DF ... used to preset data values controlling the Dynamic Beam Focus circuit drive signal.
1. Use AUDIO button to select a Sub Function
2. Use the VIDEO button to select an Adjustment Item.
3. Use the ADJUST buttons to change data.
FINE CONV (Press 4)
Sub Functions
This mode is used to perform Fine Raster Correction, and Fine Red and Blue Convergence Adjustments.
There are three Sub Adjustment Functions, selected with the AUDIO button:
* FINE GREEN .... a Green Cross-hatch is displayed, for Fine Raster Corrections.
* FINE RED.... a White Cross-hatch is displayed, for Fine Red Convergence Adjustments.
* FINE BLUE.... a White Cross-hatch is displayed, for Fine Blue Convergence Adjustments.
Cursor
In the Fine mode a Cursor is added to the Cross-hatch. The ENTER button toggles the Cursor between two modes:
* MOVE (blinking Cursor) .... use the ADJUST buttons to select any of 64 points on the Cross-hatch.
* ADJUST (Non blinking Cursor).... the ADJUST buttons adjust the active colour at the current Cursor position, horizontally or vertically.
Cursor Coordinates
Specific intersections in the Cross-hatch are assigned vertical and horizontal coordinates.
These are shown in the preceding diagram. The Cursor can only be moved to those positions that have coordinates assigned. If the Cursor is at coordinates outside the screen area, the Cursor will not be visible. Use the ADJUST buttons to move the Cursor to an intersection on the screen.
Display
The on-screen display changes in the Fine mode.
The display shows the vertical and horizontal data for the current Cursor Position, and the horizontal and vertical coordinates for that position.
Saving Data and Exiting the Convergence Mode
Press MENU twice to exit the Convergence mode, data is automatically saved.
Note: If power is interrupted prior to properly exiting the Convergence Mode, changes in adjustment data will not be saved.
ADJUSTMENT ITEM LIST

Monday, October 13, 2014

T’CON BOARD FAULTS AND WORKING PRINCIPLE – LCD PANEL FAULTS

LCD Panel Basics
  LCD panels have steadily evolved over the last several years. New designs of the physical structure of the LCD crystals have greatly improved the contrast ratio and viewing angle. Quicker response times and increased refresh rates have helped to reduce the motion “smear” associated with LCD displays. Backlighting design has also aided in producing a picture with color temperatures to make the images as true as possible. With all these design improvements, one aspect of the LCD panel remains relatively the same: Processing of the video signal.   A typical LCD panel and the associated video
processing circuits as found in the WAX3 chassis. The various formats and resolutions of video signals are processed on the BU1 board. All video signals exit the video processor in the native resolution of the LCD panel.  In this design, the resolution is for a 1366 by 768 at 60HZ refresh rate panel. 48 horizontal lines are discarded to match up to the 720p resolution
of the ATSC specifications so the video will exit as 720p.  The LCD panel used in this model processes 8-bit RGB video data. Before the video information can be sent to the TCON board it must be converted to a format that allows for practical and noise-free transmission. The large number of parallel lines to transmit the 8-bit RGB data would need to be sent on differential lines for noise reduction. This would require 48 lines just for the video. The TCON circuit also requires B+, ground connections, a communications bus, sync, and a clocking line transmitted differentially so we can see that up to 60 lines would be required for an 8-bit video signal and significantly more lines for a 10-bit processor. The practical way to transmit this information is to convert the parallel video data to a serial stream and this is accomplished by the Low-Voltage Differential Signaling (LVDS) transmitter.


The LVDS transmitter contains a circuit to serialize the parallel data. The parallel video information along with sync and clocking data are transmitted via twisted line pairs. Depending on the logic level, current is sent along one or the other of the twisted pair of wires. The receiving end of the wires is loaded with a resistor (usually around 100 to 120 ohms). The receiver detects the polarity of the voltage drop across the resistor to determine the logic level. The current level swings in the wire are about 3ma with a voltage differential of around 350mv. This allows for transmission of the video signal with minimal EMI.  The LVDS receiver on the TCON board converts the serialized data back to parallel. This data is processed by the timing control IC to allocate the RGB data into serial streams for processing by the LCD panel. The TCON transmits the pixel control data to the panel via flat, flexible circuit board cables which can number 2 or 4 depending on the bit rate and refresh timing of the panel. A 1366 X 768 panel requires about 180 lines to transmit control information and B+ from the TCON. This number of control lines is not even close to the number of horizontal or vertical rows of pixels so the LCD panel must use this information to further expand the ability to turn on each individual crystal. The process will be explained in the gate and source driver paragraphs.  All of this is accomplished by the TCON board. The term “TCON” is short for Timing Control. Other LCD panel manufacturers may have a different name for this particular circuit but the term used by Sony will always be TCON.
Gate Drivers
Referring to Figure 4-5, note the IC’s located along the side of the panel. These IC’s are mounted on a flexible cable(s) which are bonded to the LCD panel. Their function is to activate each row of pixels one at a time starting with the first line at the top. As each line is activated, the source drivers turn on the appropriate liquid crystals for the frame of video about to be displayed. This continues from top to bottom until the entire frame of video is displayed. The process is repeated for the next frame. This rate can vary from 60 times per second or be increased to 120 or 240 as found in the high-frame-rate panels. 
Source Drivers
These IC’s provide the control voltages to turn on each RGB segment of the vertical rows of pixels. In this example, the panel has a horizontal resolution of 1366 pixels. Each pixel is made up of a red, green and blue liquid crystal which means there are 4,098 columns to control.  The source drive IC’s contain shift registers along with buffer switches. Shift registers are used to convert serial data to parallel. By using this method, the TCON is able to transmit control information to each of the source drivers using serial data lines. If the TCON is transmitting 8-bit data to the panel, each data line is capable of controlling 256 lines exiting the source drivers. Understanding how the gate and source drivers work together makes it easier to observe a problem on the screen and determine if the failure is panel or TCON related.
Diagnosing a Failed TCON
In order for this concept to move forward successfully, it is important that the service industry be able to properly identify the symptoms of TCON issues to avoid unnecessary service calls and repair costs. Accurate analysis of TCON failures will reduce costs significantly (both in parts costs and time) when warranty repairs are involved and will reduce the number of COD repairs that are lost.  A good approach when determining a TCON failure is a good understanding of which symptoms ARE NOT caused by the TCON. Examples are as follows:
Video Process Failures: All video inputs received by the video process circuits are handled on a frame-by-frame basis. The video frames are converted and scaled to 8 or 10-bit RGB information. It is virtually impossible for the video process circuits to cause a problem on a specific area of the screen. Failures on this board usually appear as distortions, color level shifts, video level shifts, noise that involves the entire picture, or no picture at all. The TCON can generate symptoms that appear to be video process related but the video process circuits cannot produce the symptoms of a failed TCON circuit.
LVDS Cable Failures: Although problems with the LVDS cable or connectors can generate symptoms of TCON failures this usually tends to be intermittent and wiggling of the connectors will usually provoke a change in the symptom on the screen. LVDS cables and connectors have become rather robust over the past few years and most problems are caused by one who works with it damage them and this is generally quite obvious upon close examination.
LCD Panel Failures: Some LCD panel failures could possibly be mistaken for TCON issues. Other than damage to the LCD glass, most panel failures are isolated to a particular area of the screen. Since the TCON disperses the pixel data to groups of line and column drive IC’s situated on the outer edges of the panel, it is unlikely that more than one of these IC’s would fail at the same time. Multiple columns of stuck on or stuck off pixels are, therefore, more likely to be the fault of the TCON circuits. The same applies to a single row of lit or unlit pixels. The TCON simply cannot cut out a single line of information.
 Failures involving the LCD panel are usually displayed with the following symptoms:
• Physical damage such as cracks in the panel, a single pixel or group of pixels that always on or off, or random sections of the panel which are completely dark.
• Source driver failure. This symptom appears as a single vertical band around 1 to 2 inches (depending on the panel size) and can be black, white, or any other color. It can also contain video information with distortion. A single vertical line that is dark or colored. This may be due to a tab bonding failure from the IC to the panel but either cause requires the replacement of the panel.
• Gate driver failure. These IC’s operate in a “bucket brigade” fashion.  As mentioned earlier, the gates drivers scan each horizontal line starting at the top. If any one of the gate drivers fails, all of the subsequent drivers below it will fail to operate properly. This symptom is usually indicated by normal video on the upper portion of the screen followed by distorted video from the point of the failed IC and downward.
• Any horizontal lines. The gate drivers are activated by a single source of timing information so any single horizontal line or groups or random horizontal lines are caused by an output failure from a gate driver or a loss of the tab bond to the panel.
TCON Failures
Failures in the timing control circuits of the TCON can produce symptoms of absolutely no video or generate lines and patterns that usually cover all or a substantial part of the screen. Determining if the TCON is the cause of a “no video” condition is a bit more difficult since there are no indications on the screen to analyze.
Troubleshooting a “DEAD” TCON
many of the Sony television models over the last few years will detect a TCON that has completely failed. The communications data between the video process circuits and the TCON will cease to communicate if the TCON fails completely. This will cause the television to shut down and display a diagnostics code indicating a failure of the TCON. Not all chassis designs have this feature and it is not found on older models.The typical scenario when this failure arises is for the technician to bring a video process board to the repair location. It is usually safe to assume that the problem lies on the TCON board if the replacement video board does not remedy the problem since it is highly unlikely that a replacement board with the same failure was received.  One trick to check most TCONS for functionality is to loosen the LVDS connector at the TCON (as shown In Figure 4-3) while the unit is turned on. Handle the LVDS connector with care and be certain to fully release the lock tabs. Gently rock the cable in and out of the connector while observing the screen for any response. Depending on the chassis, the symptoms of the screen may be gentle white flashes, intermittent colored lines, or a screen full of random patterns. The idea at this point is to provoke some kind of response on the screen. TCON boards that have failed will not usually generate any type of response on the screen.  Another helpful procedure is to rapidly heat and/or cool the TCON with hot air devices or circuit coolant and watch for patterns to appear on the screen.
Illustrates 2 examples of a loss of control data to the drive IC’s. In the first example, an entire group of column drivers has lost the data stream for red. The second example involves the complete loss of drive data for all RGB information to the right side of the screen. This is sometimes caused by the flat cable connecting the TCON to the LCD panel coming loose. The area of missing video can be dark or completely white depending on the panel design.  Service Tip: Select an inactive input (or one that is known to be a 4:3 SD source) and toggle between the “normal” and “zoom” modes. If the lines follow the zoom changes, the problem is located on the video process board. If they stay in the same place, they are originating in the TCON Or LCD panel.

Tuesday, October 07, 2014

HOW TO ENTER SERVICE MODE TO PANASONIC TC-42P1 & TC-42P1F – WIDE PLASMA DISPLAY


TC-42P1 & TC-42P1F – WIDE PLASMA DISPLAY _ SERVICE MODE & ADJUSTMENTS
SERVICE MODE
* Press and hold the volume down / - button on the front panel of the unit and press the status [ + ] button on the remote control 3 times quickly within 1 second, this will place the unit into the CAT menu (Main service mode).
* Press the STR button on the remote control
* Select the alignment Subject by the UP or DOWN button of the Cross buttons on the * remote control.
* Select the alignment item by the LEFT or RIGHT buttons of the Cross buttons on the remote control.
* Adjust optimum setting by Volume Up / + and Down / - buttons.
TO EXIT THE SERVICE MODE  
>> To exit the IIC mode, press the menu button on the remote control.
>> To exit the CAT mode, access the ID mode by the down button of cross buttons and switch off the main power and on again.
AGING
* Aging mode is internal pattern generator for panel setting confirmation and the after image removal.
Panel Colour
There are 4 colour pattern White, Red, Blue and Green.
1. Access desired colour pattern by the Volume Up or Down button on the remote control and press the STR button.
2. To exit press Menu button.
Self Check
Display Indication
* Self-check is used to automatically check the bus line controlled circuit of the Plasma display.
>> To get into the Self-check mode press the volume down button on the customer controls at the front of the set, at the same time pressing the OFF-TIMER button on the remote control, and the screen will show.
(If the CCU ports have been checked and found to be incorrect or not located then “--” will appear in place of “OK”)
PANEL WHITE BALANCE ADJUSTMENT
* Set the AV mode and input the white pattern signal from PAL signal generator.
* Press the Menu button twice to access main menu and set the manual W/B to Cool.
* Access the Panel W/B mode and align the Low Light and High Light shown below by using colour meter.
* Change the Manual W/B to Nomal by the Menu button and STR button.
Modify the Data as follows.
* Increase R Drive 24 steps and reduce B drive 2 steps and B cutoff 1 step from Cool mode.
* Change the Manual W/B to Warm by the Menu button and STR button.
* Modify the Data as follows.
Increase R Drive 30 steps and reduce B drive 35 steps, and B cutoff 2 steps from Cool mode.
# Access the SG Hold mode (Forced singal system set mode) and set the system to NTSC.
# # Return to the Panel W/B mode and copy the Data 3 for each item.
Repeat item # and ## for SECAM system.