SHARP - LC20B6US - LCD TV _ SERVICE MODE AND ADJUSTMENTS _ FACTORY SETTINGS _ WHITE BALANCE ADJUSTMENT

How to enter service mode to sharp LC20B6 LCD TV

TO ENTER SERVICE MODE
Use the specific AC adaptor or a stable DC power supply as power source.

LC-20B6U AC adapter: UADP-A065WJPZ.

DC power supply: 12 (V), 6.6 (A) or more.
The following two methods are available to enter into service mode.

1. While holding down the "INPUT" and "VOLUME (–)" keys on the set, turn ON the power and press the "CH (Ù)" and "VOLUME (–)" keys at once.
2. Turn ON the power with either of KEY4 (pin (81) of microprocessor) and KEY5 (pin (82) of microprocessor) staying at "L".

KEY OPERATIONS AND ADJUSTMENT PROCESS

• Select a station with the station-selection UP/DOWN key.
• Switch the input with the input selector key.
• Using the cursor UP/DOWN key, select an item to be adjusted. (When the cursor DOWN key is pressed with the cursor placed on the bottom item, the cursor will move to the top item on the next page. When the cursor UP key is pressed with the cursor placed on the top item, the cursor will move to the bottom item on the previous page.).
• Adjust the selected item with the volume UP/DOWN key or the cursor RIGHT/LEFT key
• Pressing the menu key will move the cursor to the next item. (When the menu key is pressed with the cursor placed on the bottom item, the cursor will move to the top item on the next page.)
• Pressing the manual memory key will return the cursor to the top item. (When the manual memory key is pressed with the cursor placed on the top item, the cursor will move to the top item on the previous page.)
• Pressing the auto preset key will move the cursor to the top item on the next page.
• When the ENTER key is pressed with the cursor placed on an item other than I2C DATA on page 9, the setting page corresponding to the selected item will appear.
• To exit each setting page, press the "Previous Screen" key.

INITIALIZATION

• Set both pins (81) and (82) of IC2001 (microprocessor) to GND and turn ON the power
• Check the model name (A625).  # Note: MODEL cannot be changed.
• Inch size selection.  Check INCH SIZE (20)  # Note: INCH SIZE cannot be changed.

FACTORY SETTINGS

• While holding down the "INPUT" and "VOLUME (–)" keys on the set, turn ON the power and press the "CH UP" and "VOLUME (+)" keys at once.

 WHITE BALANCE ADJUSTMENT

1. Select the component -480i input.
2. Adjust "R CUTOFF2" and "B CUTOFF2" so that "White 20%" takes on the following WB target values.  Caution: "G CUTOFF2" should be fixed.
3. Adjust two strong colors of "R/G/B-GAIN" downward so that "White 80%" takes on the WB target values.  Caution: Any one of "R/G/B-GAIN" should be fixed at 64.
4. Repeat steps 2 and 3 so that "White 20%" and "White 80%" takes on the target values.
5. Enter the values of "R/B_CUTOFF2" and "R/G/B-GAIN" set in steps 2 to 4 in the corresponding items of "Composite adjustment", "Component -1080i adjustment" and "PC-VGA adjustment" shown below.
6. Select the composite input and check that "White 20%" and "White 80%" are within the inspection specifications.  Caution: The component Ys output signal of the automatic regulator should be used also when the composite input is selected. In the case of the CVBS output, the signal level is different.

• If "White 20%" and "White 80%" are not within the inspection specifications, make the adjustment described in steps 2 to 4.

• Select the component -1080i input and check that "White 20%" and "White 80%" are within the inspection.
• If "White 20%" and "White 80%" are not within the inspection specifications, make the adjustment described in steps 2 to 4.
• Select the PC-VGA input and check that "White 20%" and "White 80%" are within the inspection specifications
• If "White 20%" and "White 80%" are not within the inspection specifications, make the adjustment described in steps 2 to 4.

ADJUSTMENT VALUE

• Composite adjustment...RGB CUTOFF2 and RGB-GAIN on page 3 of adjustment process menu
• Component -480i adjustment...A RGB CUTOFF2 and A RGB-GAIN on page 4 of adjustment process menu
• Component -1081i adjustment...D RGB CUTOFF2 and D RGB-GAIN on page 5 of adjustment process menu
• PC-VGA adjustment...PC RGB CUTOFF2 and PC RGB-GAIN on page 5 of adjustment process menu.

	Adjustment value	Adjustment specifications
White 80%	x=0.295	±0.006
	y=0.305	±0.006
White 20%	x=0.292	±0.006
	y=0.301	±0.006
Remarks	The numeric values shown above are for MINOLTA CA-210.

(Reference) White 80%...luminance: 220 cd/m2, About 8000K

White 20%...luminance: 9 cd/m2, About 8400K

WB adjustment range

R/G/B CUTOFF2: –20 to +20 (G CUTOFF2 fixed at 0)

R/G/B GAIN: 36 to 64 (One of the colors fixed at 64)