JVC LT-42DR9BJ - LT-42DR9BU SERVICE MODE SELF CHECK AND POWER SUPPLY CIRCUIT

JVC LT-42DR9BJ - LT-42DR9BU SERVICE MODE SELF CHECK AND POWER SUPPLY CIRCUIT

JVC LT-42DR9BJ - LT-42DR9BU 

SERVICE MODE SELF CHECK AND POWER SUPPLY CIRCUIT 

HOW TO CHECK THE OPERATING TIME
This model has a function to count and record the LCD panel operating time. The operating time can be checked in the following procedure.
 Maximum count time = 131072 hours
(1) Press the [INFORMATION] key and [MUTING] key simultaneously, then enter the SERVICE MODE.
(2) Press the [2] key SELF CHECK MODE.
(3) The operating time of the LCD panel is displayed in 6-digit decimal number.

HOW TO RESET THE OPERATING TIME
When the LCD panel unit is replaced, be sure to reset the operating time in the following method.
(1) Press the [INFORMATION] key and [MUTING] key simultaneously, then enter the SERVICE MODE.
(2) Press the [9] key, then start the SHIPPING setting.
(3) The power of the UNIT is turned off automatically, and the OPERATING TIME is reset.

HOW TO ENTER THE SERVICE MODE
Press [INFORMATION] key and [MUTING] key on the remote control unit simultaneously to enter the SERVICE MODE SCREEN.

NOTE:
Before entering the SERVICE MODE, confirm that the setting of VCR/TV/DVD switch is at the "TV" side. If the switches have not been properly set, you cannot enter the SERVICE MODE.”

HOW TO EXIT THE SERVICE MODE
Press the [MENU] key to exit the Service mode.
CHANGE AND MEMORY OF SETTING VALUE SELECTION OF SETTING ITEM
# [FUNCTION UP/DOWN ] key.
For scrolling up / down the setting items.
CHANGE OF SETTING VALUE (DATA)
# [FUNCTION LEFT/ RIGHT] key.
For scrolling up / down the setting values.
MEMORY OF SETTING VALUE (DATA)
Changed setting value is memorized by pressing [OK] key

HOW TO ENTER THE ADJUSTMENT MODE
When the SERVICE MENU SCREEN of SERVICE MODE is displayed, press [1] key to enter the ADJUSTMENT MODE.
NOTE:
 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.

INITIAL SETTING VALUES IN THE SERVICE MODE
# Perform fine-tuning based on the "initial values" using the remote control when in the Service mode.
# The "initial values" serve only as an indication rough standard and therefore the values with which optimal display can be achieved may be different from the default values.

WHITE BALANCE ADJUSTMENT PROCEDURE

(1) Receive a PAL 75% all white signal.
(2) Set PICTURE MODE to "STANDARD".
(3) Set ZOOM to "FULL".
(4) Set COLOUR TEMP. to "NORMAL".
(5) Select "1.ADJUST" from the SERVICE MODE.
(6) Adjustment is select 1 item from <2.R DRIVE>, <3.G DRIVE> and <4.B DRIVE> then select item fix to "512" Other color shold be less than 920.
NOTE:
Finaly minimam more than 1 item (<2.R DRIVE> , <3.G DRIVE> or <4.B DRIVE>) should be "512".
(7) Must check white balance adjustment correctry with low light to high light.
(8) Press the [OK] key to memorize the set value.

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

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.

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.

Self check is performed for the following items

Detection item	Display	Detection content	Diagnosis signal (line)	Detection timing
Low bias line short protection	LOB	Confirm the operation of the low bais(1V/3.3V/5V/ 12V) protection circuit. 1V: Q9351 [MAIN PWB] 3.3V: Q9601 [MAIN PWB] 5V: Q9201 [MAIN PWB] 12V: Q9301 [MAIN PWB]	LB_PRO	Detection starts 5 seconds after the power is turned on. If error continues between 200 ms the power is turned off.
MAIN MEMORY	MEM	Confirmation of reply of ACK signal which uses I2C communication. IC7003 [MAIN PWB]	SDA	If it checks whenever I2C communication is performed and no reply of ACK signal an error will be counted.
AUDIO	AIO	Confirmation of reply of ACK signal which uses I2C communication. IC6661 [MAIN PWB]	SDA	If it checks whenever I2C communication is performed and no reply of ACK signal an error will be counted.
RF (ANALOG) TUNER	TUN	Confirmation of reply of ACK signal which uses I2C communication. TU1001 [MAIN PWB]	SDA	If it checks whenever I2C communication is performed and no reply of ACK signal an error will be counted.
HDMI	HDM	Confirmation of reply of ACK signal which uses I2C communication. IC8501 [MAIN PWB]	SDA	If it checks whenever I2C communication is performed and no reply of ACK signal an error will be counted.

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 counted.
(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. Therefore, turn on the main power, and then wait for about 3 seconds before starting Self check. If recurrences are expected, ensure to clear (reset) the failure history and record the new diagnosis results.

POWER SUPPLY CIRCUIT 

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