Toshiba MD20FM3 Service Manual Download

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ELECTRICAL ADJUSTMENTS

D-1

2. BASIC ADJUSTMENTS

2-1: CONSTANT VOLTAGE

1.
2.

3.
4.

Set condition is AV MODE without signal.
Using the remote control, set the brightness and contrast
to normal position.
Connect the digital voltmeter to TP401.
Adjust the VR502 until the digital voltmeter is 111

0.5V.

Fig. 1-2

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

FUNCTION

BRI. AV(CENT.)
BRI. AV(MAX)
BRI. AV(MIN)
COL. AV(CENT.)
COL. AV(MAX)
COL. AV(MIN)
TINT AV
SUB CONTRAST AV
CONT. AV(CENT.)
CONT. AV(MAX)
CONT. AV(MIN)
SHARPNESS AV
BRI. DVD(CENT.)
BRI. DVD(MAX)
BRI. DVD(MIN)
COL. DVD(CENT.)
COL. DVD(MAX)
COL. DVD(MIN)
TINT DVD
SUB CONTRAST DVD
CONT. DVD(CENT.)
CONT. DVD(MAX)
CONT. DVD(MIN)
SHARPNESS DVD
BRI. GAME(CENT.)
BRI. GAME(MAX)
BRI. GAME(MIN)
CONT. GAME(CENT.)
CONT. GAME(MAX)
CONT. GAME(MIN)
TUNING V MUTE
POWER ON V MUTE
INPUT LEVEL
SEPARATION L
SEPARATION H
CUT OFF

37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72

FUNCTION

R CUT OFF
G CUT OFF
B CUT OFF
G DRIVE
B DRIVE
BRIGHTNESS(CENT.)
BRIGHTNESS(MAX)
BRIGHTNESS(MIN)
COLOR(CENT.)
COLOR(MAX)
COLOR(MIN)
TINT
SUB CONTRAST
CONTRAST(CENT.)
CONTRAST(MAX)
CONTRAST(MIN)
SHARPNESS
RGB CONTRAST
H POSITION
V POSITION
V SIZE
V LINEARITY
V S CORRECTION
EW PARABOLA CORR.
EW TRAPEZIUM CORR.
H SIZE
V EHT
H EHT
RF AGC
V CENTERING
CORNER CORR. TOP
CORNER CORR. BTM
OSD H
FM LEVEL
TEST PWM
TEST TONE CONTROL

2-2: RF AGC

1.
2.
3.

Receive the VHF HIGH (63dB).
Place the set with Aging Test for more than 15 minutes.
Connect the digital voltmeter between the pin 5 of
CP101 and the pin 1 of CP101.
Activate the adjustment mode display of Fig. 1-1 and
press the channel button (29) on the remote control to
select "AGC".
Press the RIGHT/LEFT button on the remote control
until the digital voltmeter is 2.7

0.05V.

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 for a heat sink,
apply the 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).

BEFORE MAKING ELECTRICAL
ADJUSTMENTS

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

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
1 second to appear the adjustment mode on the screen
as shown in Fig. 1-1.

Fig. 1-1

Use the Channel UP/DOWN button or Channel button
(1-0) on the remote control to select the options shown
in Fig. 1-2.
Press the MENU button on the remote control to end
the adjustments.

01 RCUT
3E

Function
Step No.

2-4: CUT OFF

2.
3.
4.

Adjust the unit to the following settings.
R CUT=7F, G CUT=7F, B CUT=7F, G DRV=3F,
B DRV=3F
Place the set with Aging Test for more than 15 minutes.
Set condition is AV MODE without signal.
Using the remote control, set the brightness and contrast
to normal position.
Activate the adjustment mode display of Fig. 1-1 and
press the channel button (72) on the remote control to
select "CUT OFF".
Adjust the Screen Volume until a dim raster is obtained.

2-3: FOCUS

1.
2.
3.

Receive the monoscope pattern.
Turn the Focus Volume fully counterclockwise once.
Adjust the Focus Volume until picture is distinct.