Panasonic CT-25G5UB Service Manual - Page 18
Browse online or download pdf Service Manual for TV Panasonic CT-25G5UB. Panasonic CT-25G5UB 18 pages. Chassis: ap356m
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A
B
1
C-Board Schematic
2
C-Board Voltage Measurements (Transistors)
B
C
E
3
4
Notes:
Obtained voltages using a digital
multimeter.
The board layout has been modified
to
otherwise hidden by a mask.
5
C
CT-25G5B/UB
Q351
Q352
Q353
3.53
3.42
3.41
148.07
152.40
152.40
3.28
3.15
3.15
CHIP TRANSISTOR
LEAD DESIGNATION
Boards Designation
• A-Board - Main Board
• C-Board - CRT Board
enhance
and
display
traces
D
E
1
2.1V p-p [20
s ]
IC101 PIN 33 (DET OUT)
1.0V p-p [20
s ]
2
TP12
2.0V p-p [20
s ]
3
IC101 PIN 39 (Y IN)
1.2-1.3V p-p [20
s ]
4
IC101 PIN 43 (C IN)
Waveform Measurements
3
1.
indicates waveform measurement.
(Measurement can be taken at the
best accessible location in common
to the indicated point.)
2.
Taken
with
an
NTSC
signal
generator connected to the antenna
terminal. (NTSC color bar pattern of
8 bars of EIA colors, 100 IRE white
and 7.5 IRE black.)
3.
Customer Controls (Picture/Audio
Menu) are set to Normalize. Volume
is set to "MIN".
Schematic Notes
1.
Resistors are carbon 1/4W unless
noted otherwise.
2.
Capacitors are ceramic 50V unless
noted otherwise.
3.
Coil value notes is inductance in
H .
4.
Test point indicated by
; Test point
but no pin .
5.
Components indicated with
are
critical parts and replacement should
be made with manufacture specified
replacement parts only.
F
G
Waveforms - A-Board
3.58MHz X'tal
IC101 PIN 1
1.9V p-p [20
s ]
24.4-29.8V p-p [5ms]
7.4V p-p [20
s ]
5
9
13
17
3.58VCO
IC101 PIN 41 (SYNC)
IC451 PIN 13
IC101 PIN 16 (H SYNC)
OSC Waveform
3.8-4.8V p-p [20
s ]
4.2V p-p [5ms]
0.1V p-p [20
s ]
146.3-172.8V p-p [20
s ]
6
10
14
18
A11 PIN 1 (R)
IC101 PIN 47 (H AFC)
IC101 PIN 52 (VERT OUT)
Q501 collector (H DRIVE)
TP47R
503KHz X'tal
3.4-4.0V p-p [20
s ]
1.7V p-p [5ms]
IC101 PIN 48
208.7-252.5V p-p [20
s ]
7
11
15
19
H OSC
A11 PIN 2 (G)
IC451 PIN 7 (DRIVE)
T551 PIN 1
OSC Waveform
TP47G
3.7-4.1V p-p [20
s ]
46.7'55.1V p-p [5ms]
3.3V p-p [20
s ]
24.4V p-p [20
s ]
8
12
16
20
A11 PIN 3 (B)
IC101 PIN 50 (H OUT)
T551 PIN 6
IC451 PIN 12 (VERT OUT)
TP47B
IMPORTANT SAFETY NOTICE
4.
All video and color waveforms are
THIS SCHEMATIC DIAGRAM INCORPORATES SPECIAL FEATURES
THAT ARE IMPORTANT FOR PROTECTION FROM X-RADIATION, FIRE
taken with a wideband scope and
AND ELECTRICAL SHOCK HAZARDS. WHEN SERVICING IT IS
a probe with low capacitance (10
ESSENTIAL THAT ONLY MANUFACTURERS SPECIFIED PARTS BE
to 1). Shape and peak altitudes
USED FOR THE CRITICAL COMPONENTS DESIGNATED WITH A
may vary depending on the type
THE SCHEMATIC.
of Oscilloscope used and its
settings.
5.
Ground symbol
shown on
waveform number indicates (Hot)
ground lead connection of the
Oscilloscope.
CAUTION:
Incorrect
ground
connection of the test equipment will
result in erroneous readings.
Voltage Measurements
1.
Voltage measurement:
-
-
AC input to the Receiver is 120V.
NTSC (HD, 1125i & 525P when
6.
(BOLD LINE) indicates
applicable) signal generator is
the route of B+ supply.
connected to the antenna of the
7.
The
schematic
diagrams
are
-
Receiver. (Color bar pattern of
current at the time of printing and
100 IRE white and 7.5 IRE black.)
2.
Ground
are subject to change without
-
All Picture and Audio adjustments
ground lead connection of meter.
notice.
are set to Normalize.
Incorrect ground connection will
8.
Ground symbol
indicates HOT
TV ANT/CABLE - (Set-Up Menu)
result in erroneous readings.
GROUND CONNECTION;
in TV/ANT Mode
indicates COLD GROUND.
CAUTION:
Volume - Min.
connection of the test equipment
NOTE: All other component symbols
TV/Video SW - TV position
will result in erroneous readings.
are used for engineering
Audio Mode - Stereo
design purposes.
H
260-270V p-p [5
s ]
21
IC803 PIN 2
260-270V p-p [5
s ]
22
Collector of Q802
2.0V p-p [20
s ]
23
IC101 PIN 30
COMP SW OUT
IN
Voltage readings are nominal
and may vary ±10% on active
devices.
Some
voltage
reading will vary with signal
strength and picture content.
Supply voltages are nominal.
symbol
indicates
Incorrect
ground