Toshiba MD24F52 Service Manual page 28

1. BEFORE MAKING ELECTRICAL
ADJUSTMENTS
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. AC Voltmeter
4. Pattern Generator
5. Multi-Sound Signal Generator
On-Screen Display Adjustment
1. Set the VOLUME to minimum.
2. 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.
Function
Step No.
3. Use the Channel UP/DOWN button or Channel button (1-
0) on the remote control to select the options shown in
Fig. 1-2.
4. Press the MENU button on the remote control to end the
adjustments.
ELECTRICAL ADJUSTMENTS
01 OSD
18
NO.
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
2. BASIC ADJUSTMENTS
2-1: CONSTANT VOLTAGE
1. Place the set in AV MODE without signal.
2. Using the remote control, set the brightness and contrast
to normal position.
3. Connect the digital voltmeter to TP401.
Adjust the VR3800 until the digital voltmeter is 117 ± 0.5V.
4.
2-2: FOCUS
1. Receive the monoscope pattern.
2. Turn the Focus Volume fully counterclockwise once.
3. Adjust the Focus Volume until picture is distinct.
2-3: CUT OFF
Fig. 1-1
1. Adjust the unit to the following settings.
R CUT OFF=7F, G CUT OFF=7F, B CUT OFF=7F,
R DRIVE=3F, G DRIVE=07, B DRIVE=3F
2. Place the set with Aging Test for more than 15 minutes.
3. Set condition is AV MODE without signal.
4. Using the remote control, set the brightness and contrast
to normal position.
5. Activate the adjustment mode display of Fig. 1-1 and
press the channel button (03) on the remote control to
select "CUT OFF".
6. Adjust the Screen Volume until a dim raster is obtained.
D-1
FUNCTION NO
.
OSD 38
OSDC 39
CUT OFF 40
HPOSI 41
HBLKL 42
HBLKR 43
VSIZE 44
VPOSI 45
VLIN 46
VSC 47
VCOMP 48
RCUT 49
GCUT 50
BCUT 51
RDRV 52
GDRV 53
BDRV 54
BRTC 55
BRTX 56
BRTN 57
CNTC 58
CNTX 59
CTN 60
COLC 61
COLX 62
COLN 63
TNTC 64
SHRP 65
SBIAS 68
BRTCA 69
BRTXA 70
BRTNA 71
CNTCA 72
CNTXA 73
CNTNA 74
COLCA 75
COLXA 76
FUNCTION
COLNA
TNTCA
SHRPA
SBIASA
BRTCD
BRTXD
BRTND
CNTCD
CNTXD
CNTND
COLCD
COLXD
COLND
TNTCD
SHRPD
SBIASD
BRTCG
BRTXG
BRTNG
CNTCG
CNTXG
CNTNG
SBIASG
TVM
PVM
LVL
SEPAL
SEPAH
HFREQ
E/WDC
E/WAMP
E/WTILT
CORTOP
CORBTM
HCOMP
HBLKLA
Fig. 1-2
HBLKRA