LC-20B5E (serv.man7). Adjusting procedure of each section - Sharp TV Service Manual (repair manual). Page 2

5-1. Adjusting the common bias
       1) Make the non-signal state in the video input mode.

       2) Fit the designated tool at the center of the screen.

       3) Observe the output from the tool with the oscilloscope.

       4) Adjust the "COM BIAS" setting on Page 2 of the adjust process to minimize the wave's peak-peak level.
5-2. Adjusting the TAMP
       1) Receive the upper left of 75% white half colour bar signal.

       2) If the reading of "YDATA" on Page 2 of the adjust process is not within the range in the table below, adjust

the "PAL TAMP" setting on the same page to bring the "YDATA" setting in the range below.

~

Keep in mind that the setting may vary from model to model.

       3) Pushing the TAMP direct key finishes the "PAL TAMP" adjustment. Now the setting will be automatically

copied to "SECAM TAMP".

Model

LC-20B5E/E(F)/E(K)

Setting

174~189

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

0

0

T

A

M

P

L

7

1

1

4

Y

D

T

A

H

8

1

5

T

A

M

P

A

8

1

9

0

0

0

0

0

.

0

0

.

0

0

1

1

1

.

0

T

A

M

P

T

A

M

P

3

0

P

A

L

3

0

S

E

C

A

M

F

R

C

U

T

O

F

F

G

C

U

T

O

F

F

B

C

W

B

W

B

W

B

U

T

O

F

R

–

G

A

I

N

G

–

G

A

I

N

B

–

G

A

I

N

0

0

0

1

2

3

4

5

6

7

8

9

10

11

12

13

Y Data

(White 75%)

(Screen on Page 2 of the adjust process menu)

5-3. Adjusting the white balance
       [Input signal] Feed the composite video signal of 80% white for the screen's left, and 40% for its right.

[Settings]

80% white

x

0.291

y

0.293

40% white

x

0.279

y

0.272

[Adjusting with the bus]

Gain

Vary RB.
Keep G fixed. (not adjusted)

Cut-off Vary RB.

Keep G fixed. (not adjusted)

Initial settings of the white balance
R CUTOFF: 0

G CUTOFF: -32

B CUTOFF: 0

WB R-GAIN: 1.00

WB G-GAIN: 1.00 WB B-GAIN: 1.00