JVC LT-40X776/S SERVICE MODE AND POWER SUPPLY CIRCUIT

JVC LT-40X776/S 

SERVICE MODE AND POWER SUPPLY CIRCUIT 

SERVICE INSTRUCTIONS
SYSTEM SETTING
Be sure to carry out the following operation at the end of the procedure
 (1) Set to 0 minutes using the [SLEEP TIMER] key.
(2) Press the [VIDEO STATUS] key and [DISPLAY] key simultaneously, then enter the SERVICE MODE.
(3) When the Main Menu is displayed, press [2] key to enter the self check mode.
(4) Turn off the power by pressing the [POWER] key on the remote control unit.
FEATURES
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.
SMART CAPTION
Smart caption will appear when you press the MUTING button, only on channels where the broadcast contains CLOSED CAPTION information.
SMART SOUND
Decreases high sound levels, giving a regulated sound level.
VIDEO STATUS
Expression of a favorite screen can be chosen by the VIDEO STATUS function. [STANDARD <>DYNAMIC <> THEATER <> GAME]
DIGITAL INPUT
Digital-in will display when any picture signal (480i/ 480p, 720p/ 1080i) in Digital-in is displayed.
V-CHIP
Since the V-CHIP is built in, it can choose, view and listen to a healthy program.
MTS STEREO
The voice multiplex function of the MTS system is built in. (MTS = Multi channel Television Sound system)
NATURAL CINEMA
Watching the movie or animation, press the Natural Cinema to adjust the out line of the images to make thin more sharp.
BBE
High definition audio adds natural, clear and extraordinary sound quality to any program.
VIDEO INPUT LABEL
This function is used to label video input connections for the onscreen displays.
A.H.S.
Adds a more spacious surround sound. Music gives basic effect and Movie for more effect.
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).
HOW TO ENTER THE SERVICE MODE
(1) Set to 0 minutes using the [SLEEP TIMER] key.
(2) Press the [VIDEO STATUS] key and [DISPLAY] key simultaneously, then enter the SERVICE MODE
NOTE: Before entering the SERVICE MODE, confirm that the setting of TV/CATV switch of the REMOTE CONTROL UNIT is at the "TV" side and the setting of VCR/DVD switch is at the "VCR" side. If the switches have not been properly set, you cannot enter the SERVICE MODE.
When a number key other than the [1] keys is pressed in the SERVICE MENU 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 MENU SCREEN.
HOW TO EXIT THE SERVICE MODE
Press the [ BACK ] key to exit the Service mode.
HOW TO ENTER THE ADJUSTMENT MODE
When the SERVICE MENU SCREEN of SERVICE MODE is displayed, press [1] key to enter the ADJUSTMENT MODE
WHITE BALANCE ADJUSTMENT
(1) Receive a NTSC 75% all white signal.
(2) Set "VIDEO STATUS" to "STANDARD".
(3) Set "ASPECT" to "FULL".
(4) Select "COLOR TEMPERATURE" to "LOW".
(5) Select "1.ADJUST" from the SERVICE MODE.
(6) Adjust to keep one of < S030 > (Red drive), < S031
> (Green drive) or < S032 > (Blue drive) unchanged, then lower the other two so that the all-white screen is equally white throughout.
NOTE: Set one or more of < S030 >, < S031 >, and < S032 > to "133".
(7) Check that white balance is properly tracked from low light to high light. If the white balance tracking is deviated, adjust to correct it.
(8) Press the [MUTING] key to memoirze the set value.
SELF CHECK
HOW TO ENTER THE SELF CHECK MODE
Before entering the Self check Display mode, confirm that the setting of TV/CATV SW of the REMOTE CONTROL UNIT is at the "TV" side and the setting of VCR/DVD SW is at the "VCR" side. If the switches have not been properly set, you cannot enter the Self check Display mode.
(1) Set to "0 minutes" using the [SLEEP TIMER] key.
(2) Press the [VIDEO STATUS] key and [DISPLAY] key simultaneously, then enter the service mode.
(3) Press the [2] key (SELF_CHECK) before the service mode screen disappears.
(4) Press the [SLEEP TIMER] key to enter Page 2 of the SELF
CHECK MODE.
When the [RETURN+] key pressed, the first page change screen.
NOTE:
When a number key other than the [2] key is pressed in the SERVICE MENU SCREEN, the other relevant screen may be displayed. This is not used in the SELF CHECK. Press the [MENU] key to return to the SERVICE 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.
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
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.
POWER SUPPLY CIRCUIT 

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