Sharp LC-20A2U, Service Manual

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14
LC-20A2U
ADJUSTMENT PROCEDURES
The product has been factory-adjusted to optimum settings. If by any chance any of the settings gets out of position
or when a part has been replaced, take the following procedures.
Preparations
Use the specific AC adaptor or a regulated DC power supply.
AC adaptor: UADP-0220CEZZ
DC power supply: 13 V, 4.2 A (monitor power 3.7 A, audio amplifier power 1.0 A)
1. Adjustment Procedures
1-1. Adjusting the checker
Turning on the power (getting initialized)
→
Selecting the model number and screen size (inches)
→
Transferring the model-specified data to the setting EEPROM (I
2
C)
→
Calling the adjustment process mode
→
+B adjustment
1-2. Making finish process adjustments
Turning on the power
→
Calling the adjustment process mode (with the remote controller)
→
Adjusting the counter bias, TV contrast and white balance.
2. Calling the Adjustment Process Mode
There are two ways to enter this mode.
»
Set the KEY4 (pin (81) of IC2001) and KEY5 (pin (82) of IC2001) to the L level and turn on the power.
»
Hold down both the “TV/VIDEO” and “MENU” keys at once and turn on the main power. (Make sure “K”
appears at the top left of the screen, which means the set is in the inspection process mode.) Then press the
“CH
"
” and “VOL –” keys at once. To quit this mode, just turn off the main power. (The mode can be turned
off with the power switch either on the set or the remote controller.)
3. Key Operation in the Adjustment Process Mode
Selecting a receiving channel
»
Select an actual receiving channel with the “CH
"
/
'
” keys.
Short push-in : Channels are selected one after another.
Long push-in : Channels are skipped up to the next receivable channel.
»
Adjustments
All the items can be adjusted one by one with the “MENU”, “CH
"
/
'
” and “VOL + / –” keys (on the set and
the remote controller).
»
The “MENU” key serves to toggle between adjustment items (the next item is selected).
Let’s suppose that the item at the bottom line is now selected. Press the “MENU” key and the item at the top
line on the next page will be selected.
»
The “TV/VIDEO” key is also used to toggle between adjustment items.
Let’s suppose that the item at the top line is now selected. Press the “TV/VIDEO” key and the item at the
bottom line on the previous page will be selected.
»
Let’s suppose that the PAL/NTSC is selected on pages 11 and 12. By pressing the “VOL + / –” keys, the
register selection mode is brought on and the cursor moves to the address 01.
»
Using the “CH
"
/
'
” and “VOL + / –” keys, move the cursor vertically and horizontally, respectively. Use the
“12” key to enter the setting.
With an item selected, the cursor moves to its setting. Using the “VOL + / –” keys, the setting of the item
selected can be changed first for the left side. A new setting is now entered with the “12” key. Using the “VOL
+ / –” keys again, the right-side setting can also be changed.
0
←→
1
←→
...
←→
9
←→
A
←→
...
←→
F
←→
0
←→
...
Enter the setting with the “12” key. Go back to the address selection and go to the next item with the “MENU”
key. The cursor moves for address selection as follows using the “VOL + / –” keys.
Example : 01
←→
02
←→
03
←→
01
←→
...
Similarly the cursor moves as follows with the “CH
"
/
'
” keys.
Example : 02
←→
05
←→
...
←→
F6
←→
02
←→
...