Sharp 14LK11, Service Manual

12

14LK11

CRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT

No. Adjusting point

Adjusting procedure/conditions

Waveform and others

CRT CUTOFF
ADJUSTMENT
(I

2

C BUS

CONTROL)

1. Switch TV to VIDEO mode,BLUE BACK OFF, with

NO VIDEO signal.

2. Press R/C to set Picture Normal condition.
3. Connect the oscilloscope to Red OUT from

IC801.(TP47R)

Range

: 1 V/Div    (DC)

Sweep

: 5 msec/Div

4. Adjust SCREEN VR ,so that the tip of signal reach

3.0 Vdc + 0.1 Vdc.

1

1 V

3.0Vdc

0

Maximum
beam check

1. Receive the "Monoscope Pattern" signal.
2. Press R/C to set Picture NORMAL condition.
3. Connect the DC miliammeter between TP603 (+)

and TP602 (–).
(Full Scale: 3 mA Range)

4. Beam current must be within 720 

±

 50 

µ

A.

4

SUB-BRIGHT-
NESS
ADJUSMENT
(I

2

C BUS

CONTROL)

1. Call " SUB-BRI" in service mode. (Receive Cross-

hatch pattern with 5 black level windows)

2. Adjust the " SUB BRIGHT " bus data in order that

the line 1, 2 and 3 have the same darkness
wherelse line 4 is slightly brighter than line 1, 2
and 3 and finally line 5 will be the brighter than
line 4.

2

1, 2, 3 are in same black level.

WHITE BAL-
ANCE SERV-
ICE MODE
ADJ. (I2C BUS
CONTROL)

3

# 11,600

°

 K

X : 0.273
Y : 0.280

( MINOLTA COLOUR ANALYZER
CA-100)
*NOTE: Above DATA can be UP/
DOWN by volume key.

LOW

HIGH

14"

1.8cd/m

2

115cd/m

2

* 11,600

°

 K

DRI-GW="DRI-GS"DATA-5
DRI-BW="DRI-BS" DATA-5

1. Receive the "Monoscope Pattern" signal.
2. Press R/C  to set Picture NORMAL condition.
3. Connect the DC miliammeter between the TP 602

( - ) TP 603 ( + ).

4. Check Beam current should be around (720

µ

A)

5. Set it to service mode and adjust the DRI-G-MH,

& DRI-B-MH data to have a colour temperature
of  11,600

°

K ( white ).

6. Receive "WHITE" pattern, WITH BURST signal,

and set BRIGHTNESS Y by generator, to ** 10
cd/m2 (MINOLTA CA-100) by reducing LUMINATE
Y signal.

7. Adjust "CUT-R" & "CUT-G" to get  11,600

°

K. Then

go back NORMAL mode (HIGH BRIGHT**) to
check colour temperature. If  out of range, back
to (1).

Note: This adjustment must be  done after

warming up the unit for 30 minutes or
longer with a beam current over 500

µ

A.

DRI-R-MH=32

(FIXED)

DRI-G-MH=33

(FIXED)

DRI-B-MH=37

(FIXED)

DRI-R-MH=32

(FIXED)

1 2 3 4 5