JVC LT-40DS7BJ
SERVICE MODE AND POWER SUPPLY CIRCUIT
SYSTEM
Be sure to carry out
the following operation at the end of the procedure.
(1) Press the [INFORMATION]
key and [MUTING] key simultaneously, then enter the SERVICE MODE.
(2) When the Main Menu is displayed, press [2] key to enter the self check mode.
(3) Turn off the power by pressing the [POWER] key on the remote control unit.
(2) When the Main Menu is displayed, press [2] key to enter the self check mode.
(3) Turn off the power by pressing the [POWER] key on the remote control unit.
FEATURES
DVB-T [DS7 series only]
This TV can receive both DVB-T (Digital terrestrial broadcasting) and Analogue terrestrial broadcasting.
D.I.S.T. (Digital Image Scaling Technology)
This system uses line interpolation to double the number of scanning lines and achieve high resolution, flicker-free picture.
Colour Management
This function ensures dull colours are compensated to produce natural hues.
Picture Management
This function makes it easier to see the dark areas when a picture has many dark areas, and makes it easier to see the bright areas when a picture has many bright areas.
DVB-T [DS7 series only]
This TV can receive both DVB-T (Digital terrestrial broadcasting) and Analogue terrestrial broadcasting.
D.I.S.T. (Digital Image Scaling Technology)
This system uses line interpolation to double the number of scanning lines and achieve high resolution, flicker-free picture.
Colour Management
This function ensures dull colours are compensated to produce natural hues.
Picture Management
This function makes it easier to see the dark areas when a picture has many dark areas, and makes it easier to see the bright areas when a picture has many bright areas.
Smart Picture
This function detects the APL (Average Picture Level) and adjusts the contrast suitable for what you are watching.
DIGITAL VNR
This function cuts down the amount of noise in the original picture.
MPEG Noise Reduction
This function effects the block noise removal and mosquito NR simultaneously.
MaxxBass
This function emphasizes the bass sound.
3D Cinema Sound
You can enjoy sounds with a widerambience.
This function detects the APL (Average Picture Level) and adjusts the contrast suitable for what you are watching.
DIGITAL VNR
This function cuts down the amount of noise in the original picture.
MPEG Noise Reduction
This function effects the block noise removal and mosquito NR simultaneously.
MaxxBass
This function emphasizes the bass sound.
3D Cinema Sound
You can enjoy sounds with a widerambience.
HOW TO IDENTIFY MODELS
Except "/P"
models : "AE" is added to the serial No. after at the Rating label. "/P"
models : "PE" is added to the serial No. after at the Rating label.
TECHNICAL INFORMATION
LCD PANEL
This unit uses the flat type panel LCD (Liquid Crystal Display) panel that occupies as little space as possible, instead of the conventional CRT (Cathode Ray Tube), as a display unit. Since the unit has the two polarizing filter that are at right angles to each other, the unit adopts "normally black" mode, where light does not pass through the polarizing filter and the screen is black when no voltage is applied to the liquid crystals.
PIXEL FAULT
There are three pixel faults - bright fault , dark fault and flicker fault - that are respectively defined as follows.
BRIGHT FAULT
In this pixel fault, a cell that should not light originally is lighting on and off. For checking this pixel fault, input ALL BLACK SCREEN and find out the cell that is lighting on and off.
DARK FAULT
In this pixel fault, a cell that should light originally is not lighting or lighting with the brightness twice as brighter as originally lighting. For checking this pixel fault, input 100% of each R/G/B colour and find out the cell that is not lighting.
FLICKER FAULT
In the pixel fault, a cell that should light originally or not light originally is flashing on and off. For checking this pixel fault, input ALL BLACK SCREEN signal or 100% of each RGB colour and find out the cell that is flashing on and off.
LCD PANEL
This unit uses the flat type panel LCD (Liquid Crystal Display) panel that occupies as little space as possible, instead of the conventional CRT (Cathode Ray Tube), as a display unit. Since the unit has the two polarizing filter that are at right angles to each other, the unit adopts "normally black" mode, where light does not pass through the polarizing filter and the screen is black when no voltage is applied to the liquid crystals.
PIXEL FAULT
There are three pixel faults - bright fault , dark fault and flicker fault - that are respectively defined as follows.
BRIGHT FAULT
In this pixel fault, a cell that should not light originally is lighting on and off. For checking this pixel fault, input ALL BLACK SCREEN and find out the cell that is lighting on and off.
DARK FAULT
In this pixel fault, a cell that should light originally is not lighting or lighting with the brightness twice as brighter as originally lighting. For checking this pixel fault, input 100% of each R/G/B colour and find out the cell that is not lighting.
FLICKER FAULT
In the pixel fault, a cell that should light originally or not light originally is flashing on and off. For checking this pixel fault, input ALL BLACK SCREEN signal or 100% of each RGB colour and find out the cell that is flashing on and off.
MEMORY IC REPLACEMENT PROCEDURE
1. Power off
Switch off the power and disconnect the power plug from the AC outlet.
2. Replace the memory IC
Be sure to use the memory IC written with the initial setting values.
3. Power on
Connect the power plug to the AC outlet and switch on the power.
4. Receiving channel setting
Refer to the OPERATING INSTRUCTIONS and set the receive channels (Channels Preset) as described.
5. User setting
Check the user setting items according to the given in page later. Where these do not agree, refer to the OPERATING
INSTRUCTIONS and set the items as described.
6. SERVICE MODE setting
Verify what to set in the SERVICE MODE, and set whatever is necessary (Fig.1). Refer to the SERVICE ADJUSTMENT for setting.
1. Power off
Switch off the power and disconnect the power plug from the AC outlet.
2. Replace the memory IC
Be sure to use the memory IC written with the initial setting values.
3. Power on
Connect the power plug to the AC outlet and switch on the power.
4. Receiving channel setting
Refer to the OPERATING INSTRUCTIONS and set the receive channels (Channels Preset) as described.
5. User setting
Check the user setting items according to the given in page later. Where these do not agree, refer to the OPERATING
INSTRUCTIONS and set the items as described.
6. SERVICE MODE setting
Verify what to set in the SERVICE MODE, and set whatever is necessary (Fig.1). Refer to the SERVICE ADJUSTMENT for setting.
ADJUSTMENT PREPARATION
(1) There are 2 ways of adjusting this TV : One is with the REMOTE CONTROL UNIT and the other is the conventional method using adjustment parts and components.
(2) The adjustment using the REMOTE CONTROL UNIT is made on the basis of the initial setting values. The setting values which adjust the screen to the optimum condition can be different from the initial setting
(1) There are 2 ways of adjusting this TV : One is with the REMOTE CONTROL UNIT and the other is the conventional method using adjustment parts and components.
(2) The adjustment using the REMOTE CONTROL UNIT is made on the basis of the initial setting values. The setting values which adjust the screen to the optimum condition can be different from the initial setting
HOW TO ENTER THE SERVICE MODE
(1) Press [INFORMATION] key and [MUTING] key on the remote control unit simultaneously to enter the SERVICE MODE SCREEN.
(2) In the SERVICE MENU, press the [1] key to display ADJUSTMENT MODE SCREEN. values.
(3) Make sure that connection is correctly made AC to AC power source.
(4) Turn on the power of the TV and measuring instruments for warming up for at least 30 minutes before starting adjustments.
(5) If the receive or input signal is not specified, use the most appropriate signal for adjustment.
(6) Never touch the parts (such as variable resistors, transformers and condensers) not shown in the adjustment items of this service adjustment.
(1) Press [INFORMATION] key and [MUTING] key on the remote control unit simultaneously to enter the SERVICE MODE SCREEN.
(2) In the SERVICE MENU, press the [1] key to display ADJUSTMENT MODE SCREEN. values.
(3) Make sure that connection is correctly made AC to AC power source.
(4) Turn on the power of the TV and measuring instruments for warming up for at least 30 minutes before starting adjustments.
(5) If the receive or input signal is not specified, use the most appropriate signal for adjustment.
(6) Never touch the parts (such as variable resistors, transformers and condensers) not shown in the adjustment items of this service adjustment.
NOTE:
• Before enter the SERVICE MODE, press the [MODE] key to confirm that "TV" position is indicated. If it is in a wrong position, the SERVICE MODE operation cannot be performed.
• When a number key other than the [1] key is pressed in the SERVICE MODE SCREEN, the other relevant screen may be displayed. This is not used in the adjustment procedure. Press the [MENU] key to return to the SERVICE MODE SCREEN.
• Before enter the SERVICE MODE, press the [MODE] key to confirm that "TV" position is indicated. If it is in a wrong position, the SERVICE MODE operation cannot be performed.
• When a number key other than the [1] key is pressed in the SERVICE MODE SCREEN, the other relevant screen may be displayed. This is not used in the adjustment procedure. Press the [MENU] key to return to the SERVICE MODE SCREEN.
HOW TO EXIT THE SERVICE MODE
Press the [MENU] key to exit the Service mode.
Press the [MENU] key to exit the Service mode.
ADJUSTMENT MODE
This mode is used to adjust the VIDEO CIRCUIT and the MTS CIRCUIT.
HOW TO ENTER THE ADJUSTMENT MODE
When the SERVICE MENU SCREEN of SERVICE MODE is displayed, press [1] key to enter the ADJUSTMENT MODE.
This mode is used to adjust the VIDEO CIRCUIT and the MTS CIRCUIT.
HOW TO ENTER THE ADJUSTMENT MODE
When the SERVICE MENU SCREEN of SERVICE MODE is displayed, press [1] key to enter the ADJUSTMENT MODE.
SELF CHECK FEATURE
OUTLINE
This unit comes with the "Self check" feature, which checks the operational state of the circuit and displays/saves it during failure.Diagnosis is performed when power is turned on, and information input to the main microcomputer is monitored at all time.Diagnosis is displayed in 2 ways via screen display and LED
flashes. Failure detection is based on input state of I2C bus and the various control lines connected to the main microcomputer.
OUTLINE
This unit comes with the "Self check" feature, which checks the operational state of the circuit and displays/saves it during failure.Diagnosis is performed when power is turned on, and information input to the main microcomputer is monitored at all time.Diagnosis is displayed in 2 ways via screen display and LED
flashes. Failure detection is based on input state of I2C bus and the various control lines connected to the main microcomputer.
HOW TO ENTER THE SELF CHECK MODE
Before enter the SELF CHECK MODE, press the [MODE] key to confirm that "TV" position is indicated. If it is in a wrong position, the SELF CHECK MODE operation cannot be performed.
(1) Press the [INFORMATION] key and [MUTING] key simultaneously, then enter the SERVICE MODE.
(2) Press the [2] key SELF CHECK MODE.
(3) Press the [RED] key to enter Page 2 of the SELF CHECK MODE.
*Use the [GREEN] key to toggle between Page 1 and Page 2.
Before enter the SELF CHECK MODE, press the [MODE] key to confirm that "TV" position is indicated. If it is in a wrong position, the SELF CHECK MODE operation cannot be performed.
(1) Press the [INFORMATION] key and [MUTING] key simultaneously, then enter the SERVICE MODE.
(2) Press the [2] key SELF CHECK MODE.
(3) Press the [RED] key to enter Page 2 of the SELF CHECK MODE.
*Use the [GREEN] key to toggle between Page 1 and Page 2.
NOTE:
When a number key other than the [2] key is pressed in the SERVICE MODE screen, the other relevant screen may be displayed. This is not used in the SELF CHECK MODE. Press the [MENU] key to return to the MAIN MENU SCREEN.
When a number key other than the [2] key is pressed in the SERVICE MODE screen, the other relevant screen may be displayed. This is not used in the SELF CHECK MODE. Press the [MENU] key to return to the MAIN MENU SCREEN.
HOW TO EXIT THE SELF CHECK MODE
To Save Failure History:
Turn off the power by unplugging the AC power cord plug when in the Self check display mode. To Clear (Reset) Failure History: Turn off the power by pressing the [POWER] key on the remote control unit when in the Self check display mode.
To Save Failure History:
Turn off the power by unplugging the AC power cord plug when in the Self check display mode. To Clear (Reset) Failure History: Turn off the power by pressing the [POWER] key on the remote control unit when in the Self check display mode.
FAILURE HISTORY
Failure history can be counted up to 9 times for each item. When the number exceeds 9, display will remain as 9. Failure history will be stored in the memory unless it has been deleted.
NOTE: Only SYNC (with/without sync signals) will be neither counted nor stored. POINTS TO NOTE WHEN USING THE SELF CHECK FEATURE
Failure history can be counted up to 9 times for each item. When the number exceeds 9, display will remain as 9. Failure history will be stored in the memory unless it has been deleted.
NOTE: Only SYNC (with/without sync signals) will be neither counted nor stored. POINTS TO NOTE WHEN USING THE SELF CHECK FEATURE
In addition to circuit failures (abnormal operation), the following cases may also be Diagnosed as "Abnormal" and displayed and counted as "NG".
(1) Temporary defective transmissions across circuits due to pulse interruptions
(2) Misalignment in the on/off timing of power for I2C bus (VCC) when turning on/off the main power. Diagnosis may be impeded if a large number of items are displayed as "NG". As such, start Self check check only after 3 seconds in the case of receivers and 5 seconds in the case of panels upon turning on the power. If recurrences are expected, ensure to clear (reset) the failure history and record the new diagnosis results.
(1) Temporary defective transmissions across circuits due to pulse interruptions
(2) Misalignment in the on/off timing of power for I2C bus (VCC) when turning on/off the main power. Diagnosis may be impeded if a large number of items are displayed as "NG". As such, start Self check check only after 3 seconds in the case of receivers and 5 seconds in the case of panels upon turning on the power. If recurrences are expected, ensure to clear (reset) the failure history and record the new diagnosis results.
POWER SUPPLY CIRCUIT
CLICK ON THE IMAGE TO ZOOM IN
