Adjustment Procedure; Electrical Adjustments; Basic Adjustments - Toshiba 27A62 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 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.)
Prepare the following measurement tools for electrical
adjustments.
1. Oscilloscope
2. Digital Voltmeter
3. Multi-sound Generator
4. 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 1
second to appear the adjustment mode on the screen as
shown in Fig. 1-1.
00 OSD
3. Use the Channel UP/DOWN button or Channel button
(0-9) 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.
NO. FUNCTION NO. FUNCTION
00 OSD H 19 UNI COL CENT
01 CUT OFF 20 UNI COL MIN
02 RF. AGC 21 BRI. MAX
03 --- 22 BRI. MIN
04 H. POSI 23 COLOR MAX
05 V. POSI 24 COLOR CENT
06 H. SIZE 25 COLOR MIN
07 V. SIZE 26 TINT
08 V. CENT 27 SHARPNESS
09 V. LIN 28 RGB CONTRAST
10 VS. CORR 29 PARABOLA CORR
11 G. DRV 30 TRAPEZIUM CORR
12 B. DRV 31 CORNER CORR TOP
13 R. BIAS 32 CORNER CORR BTM
14 G. BIAS 33 V EHT
15 B. BIAS 34 H EHT
16 BRI. CENT 35 FM LEVEL
17 SUBCONT 36 LEVEL
18 UNI COL MAX 37 SEPARATION 1

ELECTRICAL ADJUSTMENTS

TV
15
Fig. 1-1
NO. FUNCTION
38 SEPARATION 2
39 TEST STEREO
40 X-RAY
41 V POS U
42 V POS L
43 H POS L
44 H POS R
45 H SIZE
46 V SIZE
47 H POSI
48 R
49 G
50 B
51 BRIGHT
52 COLOR
53 TINT
54 VCO
77 PIP INPUT SELECT
88 READ DATA
Fig. 1-2

2. BASIC ADJUSTMENTS

2-1: CONSTANT VOLTAGE
1. Set condition is AV MODE without signal.
2. Connect the digital voltmeter to the TP002.
Adjust the VR502 until the digital voltmeter is 135 ± 1V.
3.
2-2: RF AGC
1. Receive the VHF HIGH (63dB).
2. Connect the digital voltmeter between the pin 5 of
CP101 and the pin 1 (GND) of CP101.
3. Activate the adjustment mode display of Fig. 1-1 and
press the channel button (02) on the remote control to
select "RF AGC".
4. Press the VOL. UP/DOWN button on the remote control
until the digital voltmeter is 2.2V.
2-3: CUT OFF
1. Place the set with Aging Test for more than 15 minutes.
2. Activate the adjustment mode display of Fig. 1-1 and
press the channel button (01) on the remote control to
select "CUT OFF".
3. Adjust the Screen Volume until a dim raster is obtained.
2-4: WHITE BALANCE
NOTE: Adjust after performing CUT OFF adjustment.
1. Place the set with Aging Test for more than 10 minutes.
2. Receive the gray scale pattern from the Pattern Generator.
3. Using the remote control, set the brightness and contrast
to normal position.
4. Activate the adjustment mode display of Fig. 1-1 and
press the channel button (13) on the remote control to
select "R. BIAS".
5. Press the CH. UP/DOWN button on the remote control to
select the "R. BIAS", "G. BIAS", "B. BIAS", "B. DRIVE" or
"G. DRIVE".
6. Adjust the VOL. UP/DOWN button on the remote control
to whiten the R. BIAS, G. BIAS, B. BIAS, B. DRIVE, and
G. DRIVE at each step tone sections equally.
7. Perform the above adjustments 5 and 6 until the white
color is looked like a white.
2-5: FOCUS
1. Receive the monoscope pattern.
2. Turn the Focus Volume fully counterclockwise once.
3. Adjust the Focus Volume until picture is distinct.
2-6: HORIZONTAL POSITION
1. Receive the monoscope pattern.
2. Using the remote control, set the brightness and contrast
to normal position.
3. Activate the adjustment mode display of Fig. 1-1 and
press the channel button (04) on the remote control to
select "H. POSI".
4. Press the VOL. UP/DOWN button on the remote control
until the SHIFT quantity of the OVER SCAN on right and
left becomes minimum.