REPAIRING AND NOT THROWING AWAY

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!

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All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Friday, 8 March 2019

SHARP LC-20S1M SERVICE MODE AND BACK LIGHT INVERTER CIRCUIT

SHARP LC-20S1M SERVICE MODE AND BACK LIGHT INVERTER CIRCUIT


SHARP LC-20S1M 

SERVICE MODE AND BACK LIGHT INVERTER CIRCUIT 


ADJUSTING PROCEDURE
Preparation for Adjustments
Use the exclusive-use AC adapter or stable DC power supply.
AC adapter: UADP-A043WJPZ
DC power supply: 12 ± 0.5V 5.0A
Adjustment Procedure
 Adjusting the checker
Turning on the power (initialization) > Setting the model and size in inches > Transferring the model-specified data to the E2PROM (I2C) > Calling the adjustment process mode > Starting the adjustment (+B adjustment)
Adjusting the finish process
Reassembling the set >  Turning on the power > Calling the adjustment process mode (using the remote controller) > Adjusting the counter bias, TV contrast and white balance.
SERVICE MODE
There are the following two ways to choose from.
# Set the Pin (81) (KEY4) or Pin (82) (KEY5) of IC2001 (microprocessor) to "L", turn on the power.
# For servicing, hold down the "TV/VIDEO" and "MENU" keys at once, and turn on the "POWER" switch. (Make sure the process mode "K" appears at the top left of the screen.) Then press the "CH (DOWN)" and "VOL (–)" keys at once. (Make sure the adjustment process mode screen shows up.) To quit this mode, turn off the power. (Or turn off the "POWER" switch or use the remote controller’s "OFF" key.)
Using the keys for the adjustment process
Selecting a reception channel
Using the "CH (UP )/(DOWN)" key, turn up and down reception (broadcasting) channels. Just click on the key, and channels are selected on by one. Hold down the key, and the next receivable channel is searched up and down.
Adjustment items
Adjust each of the items by using the "MENU", "CURSOR UP/DOWN" and "VOL (+)/(–)" keys (on the set or o the remote controller).
Select an adjustment item using the "CURSOR UP/DOWN" key. An adjustment item is toggled on and off by activating the MENU SELECT key (next item).
Let’s suppose that the item at the bottom of a page is now selected. When the "MENU" key is activated here, the item at the top of the next page will be selected.
Initialization
1. Set pins (81) and (82) of IC2001 (microprocessor) to GND. Turn on the power.
2. Select the inch size (20).
3. Select the model number "A641M".
# Once "A641M" has been selected, the screen shuts off and the power turns off. But the power turns itself on to get the set restarted. (The microprocessor resets itself due to a change in model number)
Adjustment
 +B adjustment (R3710 Variable resistor)
1) Receive the colour bar signal.
2) Adjust the voltage at pin (4) of P3701 to 5.00 ± 0.02 V.
Note: The 5.0 V level is used as reference for all the line voltages. Make this adjustment as precisely as possible.
Counter bias adjustment
Adjust the "COM BIAS" setting until the contrast gets optimum (the black portion blackest). The adjustment guideline is around 95.
TAMP adjustment
1) Feed the colour bar pattern signal.
2) See if the "Y" reading on adjustment process page 2 is within the range shown below. If not, adjust the "NTSC TAMP" setting to bring the "Y" reading within the specified range
Adjustment value 187>202
3) If the "NTSC TAMP" setting has been readjusted, write down its new setting in the "PAL TAMP" and "SECAM TAMP" items manually.
White balance adjustment
1) Feed the monoscope pattern signal.
2) Adjust the "RCUTOFF", "BCUTOFF", "R-GAIN" and "B-GAIN" settings on adjustment process page 3 to achieve the colour at the same level as with the standard set.
Other adjustments (SOUND, VPC, DPS, DAC, TUNER, OTHERS, TEXT)
1) Move the cursor to a desired item on page 4 of adjustment process menu. Press the CURSOR LEFT/ RIGHT keys, "VOL (+)/(–)" keys or OK key to select the item.
2) The adjustment process menu of the item appears on the screen. The settings are now ready to change.
3) To go back to page 4 of adjustment process menu, press the FLASHBACK key on the remote controller.
Lamp error detection
Functional description
This LCD colour television has a function (lamp error detection) to be turned off automatically for safety when the lamp or lamp circuit is abnormal. If the lamp or lamp circuit is abnormal, or some other errors happen, and the lamp error detection is executed, the followings occur.
1 The main unit of television is turned off 5 seconds after it is turned on. (The power LED on the front side of TV turns from green to red.)
2 If the situation 1 happens 5 times sequentially, television can not be turned on. (The power LED remains red.)
Countermeasures
Check when turning off the lamp error detection
When television is turned off by the lamp error detection mentioned above, it enters the adjustment process with the power LED red. Entering the adjustment process turns off the error detection and turns on TV.
This enables the operation check to detect errors in the lamp or lamp circuit. Check whether "ERROR NO RESET" on line 4, page 1 of the adjustment process is 1 or more. If it is 1 or more, it indicates the lamp error detection was executed.
Resetting of the lamp error count
After confirming that the lamp or lamp circuit is normal, reset the lamp error count. Select "ERROR NO RESET" on line 4, page 1 of the adjustment process and set the number to 0 using the volume button.
Public mode
How to enter into PUBLIC MODE
1. Turn off TV by pressing MAIN POWER switch.
2. While pressing "VOL(+)" key and "CH(UP)" key at the same time, press MAIN POWER switch for more than
2 seconds.
TV will turn on, and you will see the screen display a setting of PUBLIC MODE.
Setting screen of “PUBLIC MODE”
1. You can select each item of functions by pressing cursor UP/DOWN keys or CH(UP)/(DOWN) Keys on the remote control or CH(UP)/(DOWN) keys on the LCD TV. The letter of selected item turns to yellow colour when you selected it.
2. The setting position of each item of functions are made by pressing cursor RIGHT/LEFT keys on the remote control or VOL (+)/(–)keys on the LCD TV.
3. Select ENTER position after you set all functions, and press cursor RIGHT/LEFT keys on the remote control or VOL(+)/(–)keys on the LCD TV for confirmation.
Unless otherwise you make ENTER confirmation, the settings will not be memorized.
BACK LIGHT INVERTER CIRCUIT 
CLICK ON THE IMAGE TO ZOOM IN
Posted By: FRANK at 06:14
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