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8

3. 

Shading

Purpose :
To correct variations in the left and right shading due to
differences in the positions of the projection tubes, to
correct gamma and to blank the final sweep interval.

Shading Correction :
Horizontal parabola wave is made by horizontal plus via
Q7741-Q7744 and Q7745-7747.  H.SAW wave and

H.PARA wave is input to Pin No. 2 and 5 of IC7704, then
they are mixed in the IC7704 and then it is output from pin
No. 7 o IC7704.
The correction wave-form output from IC7704 is input to
pins 10 and 8 of IC7703, the R and B gain is adjusted, and
then the left and right brightness are varied to correct any
lack of colour uniformity on the screen.

4. 

Prevention of projection tube burn-out

Purpose :
This feature operates to prevent burn-out from occurring in
the phosphor substance of the projection tube when the
picture is stopped for an extended period.

Operation :
Each time the power is turned off, the channel is changed,
or AV input switching is performed, the screen display
position is moved and rotated horizontally and vertically
approximately 3 mm in a clockwise direction.
The MPU sends a command to move the screen display
position horizontally and vertically, to IC1309, through the
I²C Bus, for an input from the button on the TV, or from the
remote control, to turn the power on or off, or change the
channel, or switch the AV input.

A3

W2

7

H.SAW

Q7741

|

Q7744

HP-BLK

H.PARA

Q7745

|

Q7747

ADJ.

2

Q7748

7

5

10

8

19

18

20

R-gain

B-gain

TPW101

TPW117

6

TPW2

+12V

R-out

G-out

B-out

(H.V)

(H+1.V)

(H.V+1)

(H+1.V+1)

9

5. 

Single colour mode

Operation :
During the service mode, each colour (R,G and B) can be
displayed in P-Conver mode by using ” key of remote
control.
Command data is sent to IC7707(DAC) from IC1101(MPU)
via IIC bus line.
Then the voltage is output from pin No.1, 2 and 9 of IC7707
as follows.

IC7707 Pin No.

1

2

9

B

H

L

H

G

L

H

H

R

H

H

L

R+G+B

L

L

L

Above voltage are applied to Q7718, Q7717 and Q7715 as
blanking plus though Q7728-30.

6. 

Fan control

E3D chassis is required cool  fan to falling the temperature
of inside of unit.

Operation:
The temperature is detected by thermistor, then its result is
infromed to pin 11 of MPU.
When the temperature rises  to 90 ºC (point A), from pin 48
of MPU outputs “H” voltage, and then FAN is rotated.

After that temperature falls to 80 ºC (point B), from pin 48
MPU outputs “L” voltage, and then FAN is stopped to rotate.

Protection:
   During following conditions, Pin 7 of MPU receives “H”
voltage,then protection circuit is operated. Set goese to
stand-by mode.
a)A5/SG7 connector and SG8 connector are disconnected.
b)The FAN is deffective itself.

59

60

CLK DATA

16

1

2

B BLK

9

G BLK

R BLK

14

15

+9V

+9V

Q7730

Q7729

Q7728

1

2

B

9

G

R

Q7718

Q7717

Q7715

70

Temperature

of inside of

unit

(ºC)

80

90

100

Off

Low

Point A

Point B

Off

Low

On

High

FAN condition
MPU pin 48

FAN OUT

FAN IN

11

48

PROTECT

7

A47

1

1

SG8

3

FAN

PROTECT

FAN

A5 / SG7

6

4

90 ºC = 0.8 V
80 ºC = 1.1 V

10

7. 

Protection   

Relay

Protect

A2/W1

7

Q7115 <R>

Q7117 <G>

Q7118 <B>

CRT STOP

Q1030(INV)

RL6701

Q6751

+22V Short

circuit

D7755

-12V Short

circuit

+12V Short

circuit

+22V Over

current

Q7543

Q7545

-22V over

current

210V Short
circuit D863

140 over
current  R862

23V short
circuit D859

15V short
circuit D855

Q848

-22V Short

circuit

D7549

Q849

Q846

8V short
circuit D853

+8V(H) short
circuit D870

-15V short
circuit D850

D7577<A>

D7560<A>

D500<B>

D514<B>

D400<C>

D868<B>

D869<B>

D861<B>

Standby LED

D1004

EHT
D513

V-
Break
IC451

FB
T

FBT

Pin1

ABL

X-ray
IC411

LED

Pin 7 of IC1101 input
Holddown

à 1.354-2.308V

Shutdown

à 2.554-3.508

Abnormal

à 3.754-5.000V

Pin12 of IC1101 output

<A>

<B>

<C>

   

4sec

Q511

Q400

Q503

E8

4

12

27

7

D11

8

P11

4

11

To prevent smoke, fire and the radiation of X-rays due to

abnormally high voltages by using detection circuits (listed

below) to instantly turn off the power in the event of a

problem. Also, depending on the circuit, the projection

tubes can be damaged in the event of a problem; therefore,

there is also a circuit that informs the blanking circuit when a

problem arises so that the video signals to the cathodes can

be blanked.

There is a circuit that prevents the power being turned on by

remote control once a problem is detected as follows;

1) Convergence –22V short-circuit (LED blink one time)

2) Convergence +22V short circuit (LED blink one time)

3) Convergence –12V short-circuit (LED blink one time)

4) Convergence +12V short circuit (LED blink one time)

5) Convergence +12V short circuit (LED blink one time)

6) Convergence +22V over current (LED blink one time)

7) Convergence –22V over current (LED blink one time)

8) Convergence –22V short-circuit (LED blink one time)

9) X-ray (LED blink two times)

10) Extra High Tension (EHT) (LED blink two times)

11) V-stop (LED blink  three times)

12) +210V short circuit (LED blink two times)

13) +140v over current (LED blink two times)

14) +23V short circuit (LED blink two times)

15) +15V short circuit (LED blink two times)

16) +8V short circuit (LED blink two times)

17) +8(H)V short circuit (LED blink two times)

18) -15V short circuit (LED blink two times)

Protection line of each circuit is connected to IC1101 pin 7.

When some of these pins go to “H”, this abnormal

information is informed to IC1101 (MPU) .

Then RELAY output pin No.27 of IC1101 voltage to “H”,

Q1030 turns ON, Q6751 base voltage drops to LOW and

trips the power supply relay  RL6701. In such cases, the

main unit power lamps blinks to indicate that a protection

circuit is operating. (refer to LED blink time)