REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

©2010, 2011, 2012, 2013, 2014 Frank Sharp - You do not have permission to copy photos and words from this blog, and any content may be never used it for auctions or commercial purposes, however feel free to post anything you see here with a courtesy link back, btw a link to the original post here , is mandatory.
All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Saturday, 9 March 2019

JVC LT-37DS6FJ SERVICE MODE CHECK AND POWER SUPPLY CIRCUIT

JVC LT-37DS6FJ SERVICE MODE CHECK  AND POWER SUPPLY CIRCUIT


JVC LT-37DS6FJ 

SERVICE MODE CHECKABLE AND POWER SUPPLY CIRCUIT 

SYSTEM SETTING
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.
SERVICE MODE SETTING
ADJUSTMENT PREPARATION
(1) 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 values.
(2) Make sure that connection is correctly made AC to AC power source.
(3) Turn on the power of the TV and measuring instruments for warming up for at least 30 minutes before starting adjustments.
(4) If the receive or input signal is not specified, use the most appropriate signal for adjustment.
(5) Never touch the parts (such as variable resistors, transformers and condensers) not shown in the adjustment items of this service adjustment.
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.
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.
# 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.
WHITE BALANCE
(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) 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 "85".
(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 MODE
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.
(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 1 and 2.
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.
EXIT THE SELF CHECK MODE
Turn off the power by unplugging the AC power cord plug whe 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
ITEMS UNDER SELF CHECK
Detection item
Display
Detection content
Low bias line short
protection



LOB


Confirmation of operation of the low bais (2.5V / 3.3V / 5V / 9V) protection circuit. Q9801 , Q9822 [REGULATOR PWB]

Abnormal rise of
temperature in audio
circuit


FAN


Confirmation of the temperature of
audio circuit. TH6661 [ANALOG SIGNAL PWB]


Presence of sync signal






SYNC





Confirmation of presence of video
sync signal.
M : Main sync signal
S : Sub sync signal
HD : Component sync signal
IC201 [ANALOG SIGNAL PWB]

AC power input

TIM

Not used.

Main CPU
communication
MSM

Not used.


Digital tuner

DIGI

Not used.
Main memory




MEM


Confirmation of reply of ACK signal
which uses I2C communication.
IC7602 [DIGITAL SIGNAL PWB]

AV select switch



AVSW

Same as above.
IC301, IC501 [ANALOG SIGNAL PWB]

3 dimensions YC
separator

YC


Not used.


Multi sound process
AIO

Not used.


RF tuner




TUN


Confirmation of reply of ACK signal
which uses I2C communication.
TU3002 [RECEIVER PWB]

Ghost reduction
GCR
Not used.
DIST process



IP



Confirmation of reply of ACK signal
which uses I2C communication.
IC3001 [DIGITAL SIGNAL PWB]

RGB process



RGB

Confirmation of reply of ACK signal
which uses I2C communication.
IC3001 [DIGITAL SIGNAL PWB]
DVI (Digital communication)
DVI
Not used.

Digital input

HDMI
Confirmation of reply of ACK signal
which uses I2C communication.
POWER SUPPLY CIRCUIT 

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