Panasonic TX-28F250A-AUSTRALIA User manual

Order No. MTV0501356C3
Colour Television
TX-28F250A-AUSTRALIA
GP2 Chassis
SPECIFICATIONS
Specification
Power Source AC SINGLE 230-240V, 50 Hz
Power Consumption 149 W
Standbycondition : 2W
Aerial Terminal Impedance : 75 , Coaxial type
Tuning System FrequencySynthesizer
AutoSearchTuning
Pos: 100 Positions
Receiving System 21 Systems
Receiving Channels Regular TV
VHFBAND 0-12 (PAL/SECAM B, K1)
0-12 (PALB AUST.)
1-9(PALB N.Z.)
1-12 (PAL/SECAM D)
1-12 (NTSC M JAPAN)
2-13 (NTSC M U.S.A)
UHFBAND 21-69 (PALG, H, I/SECAM G, K,
K1)
28-69 (PALB AUST.)
13-57 (PALD, K)
13-62 (NTSC M JAPAN)
14-69 (NTSC M U.S.A.)
CATV S1-S20 (OSCAR)
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1-125 (U.S.A. CATV)
C13-C49 (JAPAN)
S21-S41 (HYPER)
Z1-Z37 (CHINA)
5A, 9A(AUST.)
IntermediateFrequency 38.0MHz
Video 31.5MHz (D, K) / 32.5MHz (B, G)
32.0MHz (I) / 32.5MHz (M)
Sound 33.57 MHz (PAL) /
Colour 33.6MHz (SECAM)
34.42 MHz (NTSC) /
33.75 MHz (SECAM)
Video/Audio/Terminals
AV 1, 2, 3, 4 S-VideoIn
Y:1Vp-p, 75
C:0.3Vp-p, 75
DVD
Y1.0Vp-p, 75
PB0.7Vp-p, 75
PR0.7Vp-p, 75
VideoIn 1Vp-p, 75
AudioIn Approx. 0.5V, 47K
MonitorOut
VideoIn 1Vp-p, 75
AudioIn Approx. 0.5V, 47K
High Voltage 31.0±1.0at zero
beam current
Picture Tube W66MAF185X Type28 (65.6cm)
Measureddiagonally
104° deflection
AudioOutput 20 Wspeaker
Dimensions(WxD xH) 731 mm x545 mm x498 mm
Weight (Mass) 41 kg(Net)
Note:
Specificationsare subject tochangewithout notice. Mass and
dimensionsshownare approximate.
2005 Matsushita ElectricIndustrial Co., Ltd. All rights reserved.
Unauthorized copying and distribution isaviolation of law.
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1. Safety Precautions
1.1. General Guide
1. Itisadvisableto insert an isolation transformer inthe AC supply
before servicing ahot chassis. Fig. 1.
Fig. 1
2. When servicing, observe the original lead dress, especiallythe
lead dress inthe high voltage circuits. Ifashort circuitisfound,
replace all parts which have been overheated or damaged bythe
short circuit.
3. After servicing, observe that all the protective devices such as
insulation barriers, insulation papers, shields, and isolation R-C
combinations, are properlyinstalled.
4. When the receiver isnot to be used for along period of time,
unplug the power cord from the AC outlet.
5. Potential, as high as 32kV ispresent when thisreceiver isin
operation. Operation of the receiver without the receiver power
supply. Servicing shouldnot be attempted byanyone who isnot
thoroughlyfamiliar with the precautions necessarywhen working
on high voltage equipment. Alwaysdischarge the anode of the
picture tube to the receiver chassisbefore handling the tube.
After servicing make the following leakage current checks to
prevent the customer from being exposed to shock hazards.
1.2. Leakage Current ColdCheck
1. Unplug the AC cord and connect ajumper between the two
prongs on the plug. Fig. 2. Fig. 2
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2. Turn on the receiver’spower switch.
3. Measure the resistance value, with an ohmmeter, between the
jumpered AC plug and each exposed metalliccabinet part on the
receiver, such as screw heads, aerials, connectors, control shafts,
etc. When the exposed metallicpart has areturn path to the
chassis, the reading shouldbe between 4M and 20M . When
the exposed metal does not have areturn path to the chassis, the
reading must be zero.
1.3. Leakage Current Hot Check (See Fig. 1)
1. Plug the AC cord directlyinto the AC outlet. Donot use an
isolation transformer for thischeck.
2. Connect a2k , 10 Wresistor inseries with an exposed metallic
part on the receiver and an earth such as awater pipe.
3. Use an AC voltmeter, with high impedance type, to measure the
potential across the resistor.
4. Check each exposed metallicpart, and measure the voltage at
each point. Fig. 3. Fig. 3
5. Reverse the AC plug inthe AC outlet and repeat each of the above
measurements.
6. The potential anypoint shouldnot exceed 1.0V rms. Inthe case of
ameasurement being outside of the limits specified, there isa
possibilityof ashock hazard, and the receiver shouldbe repaired
and re-checked before itisreturned to the customer. Fig. 4.
Fig. 4
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1.4. X-Radiation
Warning :
1. The potential sources of X-Radiation inTV sets are the EHT
section and the picture tube. /
2. When using apicture tube test rigfor service, ensure that the rig
iscapableof handling 30 kV without causing X-Radiation. /
Note: It is important touse anaccurate periodicallycalibratedhigh voltage meter. /
1. Set the brightness to minimum.
2. Measure the High Voltage. The meter reading shouldindicate 31.0
± 1.0kV. Ifthe meter indication isout of tolerance, immediate
service and correction isrequired to prevent the possibilityof
premature component failure.
3. To prevent the possibilityof X-Radiation, itisessential to use the
specified picture tube.
1.5. GP2 Block Diagram
2. Service Hints
2.1. How to move chassisinto service position
1. Remove 9screws.
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2. Draw out MainChassis.
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3. Stand the MainChassis.
3. Market Mode Function
Outline:
MPU controls the functions switching foreachICs through IIC bus inthis chassis. The following
setting and adjustment canbe adjustedbyremote control inMarket Mode.
1. Selection of Market Mode
Adjust the VOLUME “zero” and set OFF TIMERButton to 30 min.
Then, simultaneouslypress the RECALL Button on the remote
control and the VOLUME DOWNbutton -the TV set.
2. Selection of Service Mode
Press green button to select for adjustment mode, to adjust press
yellow or blue button.
3. Set to normal mode
Press the volume downbutton on front control, together press the
off timer button on remote control.
1. Service 1
H-Pos ..... 33
V-pos ..... -19
H-Pos ..... -17
V-Amp ..... 6
Ew-AMP ..... 6
Lower Corner ..... 20
Trapez 1..... -2
Upper Corner ..... 15
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V-Lin..... -8
V-Sym..... 56
Angle..... 2
Bow ..... -4
DVCO ..... 3
2. HIGH..... 0327, 0323, 0324
3. LOW..... 0173, 0204, 0232
Sub Brightness 67
4. Adjustment Procedure
4.1. Adjustment Procedure
4.1.1. +B Voltage
Item/ preparation
1. Operate the TV set.
2. Set control as follows:
Brightness ........... minimum
Contrast ............... minimum
Adjustment procedure
1. Confirm the DC voltage at the indicated test points, as follows:
TPD2:144.8± 1V
TPD21 :13.5V ± 1V
TPD3~ TPD4:32V ± 3V
4.1.2. RFAGC
Item/ preparation
1. Receive acolour bar signal at an RFlevel of 69 +1-2 dBU with 75
loaded.
2. Connect digital multimeter to RFAGCat Tuner.
Adjustment procedure
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1. Select “RFAGC”indication inCHK2, on Screen byremote control
at factorymode.
2. Set RFAGCbyusing remote control Volume (+)or Volume (-)
button until voltage AGCat Tuner reaches 2.6± 0.1V at TPA15
(Tuner point).
3. Increase RFsignal strength by2dB, confirm AGCat Tuner voltage
drop.
4.1.3. High Voltage
Item/ preparation
1. Receive the crosshatch pattern.
2. Set to 0Beam.
Screen VR.......... minimum
Contrast .............. minimum
Adjustment procedure
1. Connect aDC voltage meter to TPD2and confirm the +Bvoltage
is144.8± 1V.
2. Connect ahigh frequencyvoltmeter to heater and confirm that
voltage reads 6.3± 0.24 (VRMS).
3. Normalize the brightness and contrast.
4.1.4. NTSC TINTCOLOUR
Item/ preparation
1. Connect oscilloscope probe to A2(ROUT) with 10k series
resistor.
2. Press MainMenu and set system to use AV-NTSC(3.58 MHz).
DYNAMIC................... Normal
Channel CLRSet ..... STD
Adjustment procedure
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1. Adjust Sub-Tint so that No. 2, 3and 4becomes level waveform is
similar to Fig. 3.
2. Confirm phase at Tint ischanges more than ± 15 byTint control.
3. Confirm that colour level ismaximum when colour DAC is
adjusted to maximum position.
Note: Use remote control onlywhen adjusting user mode to Sub-
Tint.
4.2. Colour Purity
1. Set Bright and Contrast controlsto theirmaximum positions.
2. Operate the TV set over 60 minutes.
3. Full degauss the picture tube byusing an external degaussing
coil. Byrotating R-Bstaticconvergence magnet.
4. Applyacrosshatch pattern signal and adjust roughlythe static
convergence magnets.
5. Applyagreen pattern signal.
6. Loosen aclamp screw for the Deflection Yoke and move the
Deflection Yoke as close to the puritymagnet as possible.
7. Adjust the puritymagnet so that avertical green fieldisobtained
at the center of the screen.
8. Slowlypress the Deflection Yoke and set itwhere auniform green
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