Sharp LC-20B2EA, Service Manual

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11
LC-20B2EA
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
2
C O M B I A S 2 0
P A L T A M P 2 7
1
S E C A M T A M P 2 7
G C U T O F F
R C U T O F F
0
–
5
B C U T O F F
G 3 B 3 R 3 0 0 0 0 0 0
– 1
G 1 B 4 Y 0 0 0 0 B E
T A M P H
T A M P L
C A
B B
0
1
2
3
4
5
6
7
8
9
10
11
12
13
Y Data
(White 75%)
4. Initialization
When the microprocessor (IC2001) or the EEPROM (IC2004) has been replaced or when the EEPROM has been
initialized, readjust the each adjustments.
4-1. Connect the pins (81) and (82) of IC2001 (microprocessor) to GND, and turn on the power.
4-2. Select the model name to (C2EA).
4-3. Select the inch size (20).
4-4. LED changes green from red after setting finish and about 15 seconds, initialization is completed, and it
becomes adjustment mode.
5. Adjustment
5-1. +B adjustment...Page 1 +B-ADJ
Adjust the voltage of the pin (13) of P2002 to 5.00 ±0.02V.
Note: Since 5.0V is a reference voltage of all power voltage, adjust it precisely.
5-2. Counter-bias adjustment
Vary the "COM BIAS" setting on Page 2 of the adjustment process mode so that the contrast be sharpest
(black looks most sinking).
5-3. TAMP adjustment
1) Receive the upper left of 75% white half colour bar signal.
2) See if the “Y” reading on page 2 of the adjusment process mode is somewhere following. If not, make the
“PAL TAMP” adjustment to get the “Y” reading in the range of BF thru C9.
3) If the adjustment of “PAL TAMP” is executed, write its adjustment value to the “SECAM TAMP” manually.
(Screen of the page 2 of the adjustment processing menu OSD)
5-4. White balance adjustment
Adjust “RCUTOFF” and “BCUTOFF” on the page 2 of the adjustment processing so as to obtain the colour
of the same level as the standard set.
Note: For the adjustment processing of “RCUTOFF” and “BCUTOFF”, adjust them in the indication value
range of ... –9, –7, ... –1, +1, ... +7, +9.
When it becomes even-numbered value, side favor noise sometimes occurs in the monochrome signal of
the specific gradation.