SHARP LC-20SH4U ADJUSTMENT MODE AND POWER SUPPLY CIRCUIT

SHARP BLU RAY

SHARP LC-20SH4


ADJUSTMENT MODE AND POWER SUPPLY CIRCUIT 

ADJUSTING PROCEDURE OF EACH SECTION
The best adjustment is made before shipping. If any position deviation is found or after part replacement is performed, adjust as follows.
Preparations
(1) Plug the AC power cord directly into a wall outlet.
[1] Adjustment procedure
1-1. Adjusting the checker
Turning on the power (initialization) > Making the model and size settings > Transferring the model-related data to the setting E2PROM (I2C)
1-2. Adjusting the finish process
Final assembling > Turning on the power > Calling the adjustment process mode (bus connector) > Adjusting the common bias, TAMP and white balance (cut-off and gain) settings
[2] Calling the checker mode/adjustment process mode
2-1. Calling the checker mode
* Keep KEY5 (pin (82) of microprocessor) at "L" and turn on the power.
KEY-4
KEY-5
Mode shift

H
H
Normal mode (Data is written and stored on EEP is brand-new.)
L
H
Shift to adjustment mode
H
L
Activated with the checker-oriented master ROM values (EEP still brand-new even after the checker mode)
L
L
The EEP gets initialized and the microprocessor's master values are written. (Process-adjusted settings not reprogrammed)

2-2. Calling the adjustment process mode
There are two ways to call this mode.
* Turn on the power and press the "ADJUST PROCESS" key on the remote controller.
* Keep KEY4 (pin (81) of microprocessor) at "L" and turn on the power.
* For servicing: Hold down the INPUT key and VOL (–) key at once, and turn on the power switch.
("K" appears at the top left of the screen to indicate the inspection process mode.)
> Press the CH (Ù) key and VOL (–) key at once. (The adjustment process mode screen shows up.) _ To quit, turn off the power. (Or turn off the power switch or turn off the remote controller.)
[3] Key operation in the adjustment process
Basic operation
Selecting the receiving channels
* Using the CH (UP/DOWN) keys, turn up and down an actual receiving channel.
Snap press: The channels are turned up and down one by one.
Continuous press: The next receivable channel is searched.
* Various adjustments The items are adjusted one by one by selecting on the menu screen and using the cursor key and VOL (+)/(–) keys.
* With the CURSOR UP/DOWN keys, select an adjustment item.
* Using the MENU key, the adjustment items are selected one after another.
When the bottom item on a page is already selected and the MENU key is pressed, the top item on the next page is selected.
* If any item on a page is selected and the preset key is pressed, the top item on the next page is selected.
Page 1 > Page 2 > Page 3 > Page 9 > Page 1 ...
* If any item on a page is selected and the manual memory key is pressed, the top item on the same page is selected.
* Using the CURSOR LEFT/RIGHT keys and VOL (+)/(–) keys, turn up and down the setting of a selected item.
Hierarchical shift
* When the ENTER key is pressed on any item other than I2C DATA on page 4, the setting page of the item shows up.
* To quit the setting page, press the front screen key.
[4] Initialization
4-1. Ground pins (81) and (82) of IC2001 (microprocessor) and turn on the power.
4-2. Make sure the screen size is set at 20 inches.
4-3. Make sure the model number is A630A.
[5]
5-1. Model-by-model sending data
Separately published.
5-2. ROM collection
Separately published.
[6] Adjustment
6-1. Common bias adjustment

1) Feed a built-in signal.
2) Apply the specified instrument at the center of the screen.
3) Observe the instrument output on an oscilloscope.
4) Adjust the "COM BIAS" setting on Adjustment Process Page 2 so that the peak-to-peak of the wave be
minimized.
6-2. TAMP adjustment
1) Receive the standard color bar signal.
2) See if the "Y" reading (maximum) on Adjustment Process Page 2 is within the range in the following table.
If not, adjust the "NTSC TAMP" setting on the same page to have the "Y" reading (maximum) within this range
6-3. White balance adjustment
1) Adjustment procedure
Adjust the RGB CUTOFF2 setting for white 40% first and then the RGB-GAIN setting for white 80%.
(1) Adjusting the test signal
[Input signal] White 80% (191 gradations) for the left of screen, and white 40% (92 gradations) for the right.
[Specification] RGB CUTOFF2 and RGB-GAIN settings on Adjustment Process Page 3.
Adjustment spec. Inspection spec.
White 80%
 x 0.271 0.004 0.01 Radius from the center
y 0.278 0.004 0.01 Radius from the center
White 40%
x 0.258 0.002 0.01 Radius from the center
y 0.261 0.002 0.01 Radius from the center
[Adjusting with the bus]
Cut-off (RGB CUTOFF2): Fix the G setting at "0". Vary the R and B settings accordingly. Adjustment range: ±40 Gain (RGB-GAIN): Reduce the two strong colors Adjustment range: Down to -40 (Reading with Minolta CA-210)
[7] Factory settings
7-1. Making factory settings
Use the adjustment remote controller for the factory settings.
1) Hold down the remote controller's FACTORY SETTING key.
2) Several seconds later, "SETTING COMPLETE" appears at the center of the screen. Now the settings are complete.

POWER SUPPLY CIRCUIT 
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