Electrical Adjustments; Adjustment Procedure - Toshiba 30DF56 Service Manual

1. ADJUSTMENT PROCEDURE

Read and perform these adjustments when repairing the
circuits or replacing electrical parts or PCB assemblies.
CAUTION
• Use an isolation transformer when performing any service
on this chassis.
•
Before removing the anode cap, discharge electricity
because it contains high voltage.
• When removing a PCB or related component, after
unfastening or changing a wire, be sure to put the wire
back in its original position.
• When you exchange IC and Transistor with a heat sink,
apply silicon grease on the contact section of the heat
sink. Before applying new silicon grease, remove all the
old silicon grease. (Old grease may cause damages to the
IC and Transistor.)
Prepare the following measurement tools for electrical
adjustments.
1. Oscilloscope
2. Digital Voltmeter
3. Pattern Generator
On-Screen Display Adjustment
1. In the condition of NO indication on the screen.
Press the VOL. DOWN button on the set and the Channel
button (9) on the remote control for more than 2 seconds
to appear the adjustment mode on the screen as shown in
Fig. 1-1.
00 OSD H
2. Use the Channel UP/DOWN button or Channel button
(0-9) on the remote control to select the options shown
in Fig. 1-2.
3. Press the MENU button on the remote control to end the
adjustments.
4. To display the adjustment screen for AV and YUV
mode, press the TV/VIDEO button on the remote
control to set to the AV and YUV mode.
5. To display the adjustment screen for DIGITAL mode,
press the Channel button (0-9) on the remote control to
select to the DIGITAL broadcasting.

ELECTRICAL ADJUSTMENTS

TV-A
FULL
1
Fig. 1-1
NO. FUNCTION
NO.
00 OSD H 20
01 OSD C 21
02 CUT OFF 22
03 H.POSI 23
04 H BLK L
24
05 H BLK R 25
06 H.SIZE 26
07 V. SIZE 27
08 V. POSI 28
09 V. LIN 29
10 V CORR 30
11 VS CORR
31
12 V EHT 32
13 H EHT 33
14 V BLKP 34
15 V BLKS 35
16 V LIMIT
36
17 EW PARA 37
18 TRAPE 38
19 COR TOP 39
2. BASIC ADJUSTMENTS
2-1: CONSTANT VOLTAGE
1. Place the set in AV MODE without signal.
2. Press the PIC SIZE button on the remote control to
select the FULL screen mode.
3. Connect the digital voltmeter to the TP401.
Adjust the VR501 until the digital voltmeter is 135 ± 0.5V.
4.
2-2: CUT OFF
1. Press the PIC SIZE button on the remote control to select
the FULL screen mode.
2. Adjust the unit to the following setting.
R. BAIS=64, G. BIAS=64, B.BIAS=64,
R DRIVE=64, G DRIVE=10, B DRIVE=64
3. Place the set in Aging Test for more than 15 minutes.
4. Place the set in AV MODE without signal.
5. Using the remote control, set the brightness and contrast
to normal position.
6. Activate the adjustment mode display of Fig. 1-1 and
press the channel button (02) on the remote control to
select "CUT OFF".
7. Adjust the Screen Volume until a dim raster is obtained.
2-3: FOCUS
1. Press the PIC SIZE button on the remote control to select
the FULL screen mode.
2. Receive the cross hatch signal from the Pattern
Generator.
3. Turn the F1 VR and F2 VR fully clockwise once.
(Refer to Fig. 2-1)
4. Adjust the F1 VR so that the screen becomes clearest.
Then adjust the F2 VR.
D-1
FUNCTION NO. FUNCTION
COR BTM 40 COL.MIN
S CORR 41 TINT CENT
CORNER 42 SHARP.CENT
C PARA 43 SHARP.MAX
C SAW 44 SHARP.MIN
V SYMM 45 SUB BIAS
R.BIAS 46 TILT CENTER
G.BIAS 47 TEST STEREO
B.BIAS 48 TEST AUDIO
R.DRV 49 H FREQ
G.DRV
B.DRV
BRI.CENT
BRI.MAX
BRI.MIN
CONT.CENT
CONT.MAX
CONT.MIN
COL.CENT
COL.MAX
Fig. 1-2
Focus VR
F1 VR
F2 VR
SCREEN VR
Fig. 2-1