DOWNLOAD Panasonic TX-28PG45 Service Manual ↓ Size: 9.23 MB | Pages: 54 in PDF or view online for FREE

Model
TX-28PG45
Pages
54
Size
9.23 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / COLOUR TELEVISION
File
tx-28pg45.pdf
Date

Panasonic TX-28PG45 Service Manual ▷ View online

Colour Television
TX-28PG45
                                                                                                                          
EURO-7 Chassis
SPECIFICATIONS
Power Source:
220-240V a.c., 50Hz
Power Consumption:
135W
Stand-by Power
Consumption:
2.8W
Aerial Impedance:
75
 unbalanced, Coaxial Type
Receiving System:
PAL-I , PAL-525/60 UHF
M.NTSC
NTSC (AV only)
Receiving Channels:        UHF E21-E68
Intermediate Frequency:
Video/Audio
Video
39.5MHz
Audio
33.5MHz
32.95MHz (NICAM)
Colour
35.07MHz (PAL)
Video/Audio Terminals:
AUDIO MONITOR OUT
Audio (RCAx2) 500mV rms 1k
AV1 IN
Video (21 pin)
1V p-p 75
Audio (21 pin)
500mV rms 10k
RGB (21 pin)
AV1 OUT
Video (21 pin)
1V p-p 75
Audio (21 pin)
500mV rms 1k
AV2 IN
Video (21 pin)  1V p-p 75
Audio (21 pin)  500mV rms 10k
S-Video IN
Y: 1V p-p 75
(21-pin)
C:0,3V p-p 75
AV2 OUT
Video (21 pin)  1V p-p 75
Audio (21 pin)
500mV rms 1k
Selectable output (21 pin)
AV3 IN
S-Video IN
Y: 1V p-p 75
(4-pin)
C: 0,3V p-p 75
Audio (RCAx2)
500mV rms 10k
Video (RCAx1)
1V p-p 75
AV4 IN
Video (21 pin) 
1V p-p 75
Audio (21 pin) 
500mV rms 10k
S-Video IN
Y: 1V p-p 75
(21-pin)
C: 0.3V p-p 75
RGB (21 pin)
AV4 OUT
Video (21 pin)   
1V p-p 75
Audio (21 pin)    
500mV rms 1k
High Voltage:
30.5kV 
±
 1kV
Picture Tube:
W66EKT10X71 66cm
Audio Output:
2 x 20W (Music Power)
8
 Impedance
Headphones:
8
 Impedance
3.5mm
Accessories
supplied :
Remote Control
2 x R6 (UM3) Batteries
Dimensions:
Height:
495mm
Width:
728mm
Depth:
485mm
Net weight:
45kg
Specifications are subject to change without notice.
Weights and dimensions shown are approximate.
NOTE: This Service Manual should be used in conjunction with
the EURO-7 Technical guide.
ORDER No. SM-01020
CONTENTS
SAFETY PRECAUTIONS..........................................................................................................................................................2
SERVICE HINTS .......................................................................................................................................................................3
ADJUSTMENT PROCEDURE AND FACTORY SETTINGS .....................................................................................................4
WAVEFORM PATTERN TABLE ...............................................................................................................................................5
ALIGNMENT SETTINGS...........................................................................................................................................................6
BLOCK DIAGRAMS ..................................................................................................................................................................7
PARTS LOCATION .................................................................................................................................................................12
REPLACEMENT PARTS LIST ................................................................................................................................................13
SCHEMATIC DIAGRAMS .......................................................................................................................................................33
CONDUCTOR VIEWS.............................................................................................................................................................42
SAFETY PRECAUTIONS
GENERAL GUIDE LINES
1.  It is advisable to insert an isolation transformer in the
a.c. supply before servicing a hot chassis.
2.  When servicing, observe the original lead dress in the
high voltage circuits. If a short circuit is found, replace
all parts that have been overheated or damaged by
the short circuit.
3.  After servicing, see that all the protective devices
such as insulation barriers, insulation papers, shields
and isolation R-C combinations are correctly
installed.
4.  When the receiver is not being used for a long period
of time, unplug the power cord from the a.c. outlet.
5.  Potentials as high as 31.5kV are present when this
receiver is in operation. Operation of the receiver
without the rear cover involves the danger of a shock
hazard from the receiver power supply. Servicing
should not be attempted by anyone who is not
familiar with the precautions necessary when working
on high voltage equipment. Always discharge the
anode of the tube.
6.  After servicing make the following leakage current
checks to prevent the customer from being exposed
to shock hazard.
LEAKAGE CURRENT COLD CHECK
1.  Unplug the a.c. cord and connect a jumper between
the two prongs of the plug.
2.  Turn on the receiver’s power switch.
3.  Measure the resistance value with an ohmmeter,
between the jumpered a.c. plug and each exposed
metallic cabinet part on the receiver, such as screw
heads, aerials, connectors, control shafts etc. When
the exposed metallic part has a return path to the
chassis, the reading should be between 4M ohm and
20M ohm. When the exposed metal does not have a
return path to the chassis, the reading must be
infinite.
LEAKAGE CURRENT HOT CHECK
1.  Plug the a.c. cord directly into the a.c. outlet. Do not
use an isolation transformer for this check.
2. Connect 
2k
 10W resistor in series with an
exposed metallic part on the receiver and an earth,
such as a water pipe.
3.  Use an a.c. voltmeter with high impedance to
measure the potential across the resistor.
4.  Check each exposed metallic part and check the
voltage at each point.
5.  Reverse the a.c. plug at the outlet and repeat each of
the above measurements.
6.  The potential at any point should not exceed
1,4Vrms. In case a measurement is outside the limits
specified, there is a possibility of a shock hazard, and
the receiver should be repaired and rechecked before
it is returned to the customer.
X-RADIATION WARNING
1.  The potential sources of X-Radiation in TV sets are
the high voltage section and the picture tube.
2.  When using a picture tube test jig for service, ensure
that the jig is capable of handling 31.5kV without
causing X-Radiation.
NOTE: It is important to use an accurate periodically
calibrated high voltage meter.
1.  Set the brightness to minimum.
2.  Measure the high voltage. The meter should indicate.
30.5kV ± 1kV.
If the meter indication is out of tolerance, immediate
service and correction is required to prevent the
possibility of premature component failure.
3.  To prevent any X-Radiation possibility, it is essential
to use the specified tube.
HOT CHECK CIRCUIT
a.c. VOLTMETER
WATER PIPE
(EARTH)
TO INSTRUMENT’S EXPOSED
METALLIC PARTS
Fig. 1.
2k
 10 Watts
2
SERVICE HINTS
How to remove the rear cover
1. Remove the 9 screws as shown in Fig.2.
LOCATION OF CONTROLS
3
Fig. 2.
Fig.2.
Abb.2.
SCREWS
SCREWS
A-Board
P-Board
Screen
Focus
Z-Board
L-Board
H-Board
D-Board
G-Board
K-Board
DP-Board
DG-Board
ADJUSTMENT PROCEDURE
Item / Preparation
Adjustments
+B SET-UP
1. Receive 
Greyscale 
signal.
2.  Set the controls :-
Brightness
Minimum
Contrast
Minimum
Volume
Minimum
1.  Set the +B voltage up as follows:-
Adjust R811 so that B2 shows 148V±1V.
2.  Confirm the following voltages.
B9
5
±
0,25V B10
5
±
0,25V
B5
12
±
0,5V
B11
33
±
1,5V
B4
15
±
1V
B7
8
±
0,5V
B12 26
±
2V
B8
6
±
1V
B3
36
±
1,5V
B13
13
±
1V
B1
205
±
10V
B14
14
±
1V
CUT OFF / Ug2 Test
1. Receive 
Greyscale 
signal.
2.  Degauss the tube externally.
3.  Set the TV into Service Mode 1.
4.  Select Cut off mode.
To adjust Cutoff connect an oscilloscope to the Blue
cathode. Press "STR" and adjust "cutoff" value using the
"Yellow" and "Blue" buttons until the black level is 160V±5V,
press "STR" to store the value. Remove the oscilloscope.
Select Ug2 adjustment and adjust the screen VR until the
display shows "O.K."
FACTORY SETTINGS
Self-check is used to automatically check the bus lines and hexadecimal code of the TV set. To get in to Self-Check mode
press the down (-/v) button on the customer controls at the front of the TV set, at the same time pressing the STATUS button
on the remote control.
If the CCU ports have been checked and found to be incorrect or not located then " - - " will appear in place of "O.K.".
4
TX- 28PG45
OPTION1
0D
OPTION8
41
OPTION2
00 OPTION9
81
OPTION3
10
OPTION10
80
OPTION4
10 OPTION11
1B
OPTION5
00 OPTION12
28
OPTION6
50 OPTION13
FA
OPTION7
00 CHECK
FC
TUN1
O.K.
TUN2
-- --
DAC1
O.K.
MSP
O.K.
DOLBY
O.K.
CODEC
O.K.
DAC2
O.K.
DAC3
O.K.
MEM
O.K.
GC1
O.K.
GC2
-- --
VDU
O.K.
CIP
O.K.
RGB
O.K.
AVSW
O.K.
 To exit Self Check, switch off the TV set at the power button.
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Panasonic TX-28PG45 Service Manual ▷ Download

  • DOWNLOAD Panasonic TX-28PG45 Service Manual ↓ Size: 9.23 MB | Pages: 54 in PDF or view online for FREE
  • Here you can View online or download the Service Manual for the Panasonic TX-28PG45 in PDF for free, which will help you to disassemble, recover, fix and repair Panasonic TX-28PG45 TV. Information contained in Panasonic TX-28PG45 Service Manual (repair manual) includes:
  • Disassembly, troubleshooting, maintenance, adjustment, installation and setup instructions.
  • Schematics, Circuit, Wiring and Block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Exploded View and Parts List.