Panasonic TX-15AT1 Schematic

ORDER No. SM-02012

Colour Television

TX-15AT1
Z-M3L Chassis

SPECIFICATIONS

Power Source: 220-240V a.c., 50Hz
Power Consumption: 46W
Stand-by Power

Consumption: 1W
Aerial Impedance: 75Ω 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
Colour 35.07MHz (PAL)

Video/Audio Terminals:

AV1 IN Video (21 pin) 1V p-p 75Ω

Audio (21 pin) 500mV rms 10kΩ
RGB (21 pin)
Audio (RCAx1) 500mV rms 10kΩ
Video (RCAx1) 1V p-p 75Ω

AV1 OUT Video (21 pin) 1V p-p 75Ω

Audio (21 pin) 500mV rms 1kΩ

High Voltage: 26.5kV ± 1kV
Picture Tube: A36AKJ13X02E 37cm

Audio Output: 3W (Music Power)

8Ω Impedance

Headphones: 8Ω Impedance

3.5mm

Accessories
supplied : Remote Control

2 x R6 (UM3) Batteries

Dimensions:

Height: 368mm
Width: 388mm
Depth: 387mm

Net weight: 11kg

Specifications are subject to change without notice.
Weights and dimensions shown are approximate.

CONTENTS

SAFETY PRECAUTIONS..........................................................................................................................................................2

SERVICE HINTS.......................................................................................................................................................................3

ALIGNMENT SETTINGS...........................................................................................................................................................4

WAVEFORM PATTERN TABLE...............................................................................................................................................5

BLOCK DIAGRAMS..................................................................................................................................................................6

PARTS LOCATION...................................................................................................................................................................7

REPLACEMENT PARTS LIST..................................................................................................................................................8

SCHEMATIC DIAGRAMS.......................................................................................................................................................12

CONDUCTOR VIEWS.............................................................................................................................................................17

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 27.5kV 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 a 2kΩ 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.

HOT CHECK CIRCUIT

a.c. VOLTMETER

2kΩ 10 Watts

TO INSTRUMENT’S EXPOSED
METALLIC PARTS

Fig. 1.

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 27.5kV 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.

26.5kV ± 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.

WATER PIPE

(

EARTH)

2

SERVICE HINTS

How to remove the rear cover

1. Remove the 5 screws as shown in Fig.2.

SCREWS

LOCATION OF CONTROLS

SCREWS

Fig. 2.

AV Board

Main Board

CRT Board

Focus

Screen

3

ALIGNMENT PROCEDURE AND OPTION SETTING

Entering SERVICE mode

To enter the On-Screen display adjustment, adjust the unit to channel 99, select the sharpness setting using the function (F)
button. Set the sharpness to a minimum using the minus button. Press function key again to store the sharpness setting.
Then press the DOWN button on the unit whilst pressing the MUTE button on the remote control. Select the adjustment
items by the UP/DOWN button on the remote control, then adjust them by the +/- button. After adjustment , be sure to press
the TV/AV button to confirm the required values. Press the function key to store all adjustment values

Service mode navigation

- Up /Down remote keys :cycle through the service items available.

- -/+ remote keys :Decrement/Increment the values within range.

- TV/AV :Store the current data.

Order

1 Cut off (UG2) TEST

2 Vertical slope (V-slo) 031

3 Vertical position (V-pos) 033

4 Vertical amplitude (V-Amp) 029

5 Horizontal position (H-Ctr) 030

6 Red Cut (R-Cut) 035

7 Green Cut (G-Cut) 028

8 Red Drive (R-Drv) 026

9 Green Drive (G-Drv) 037

Item

Optimum setting

10 Blue Drive (B-Drv) 029

11 AGC 031

12 Sub-Colour (S-Col) 019

13 Sub-Brightness (S-Bri) 029

Cut Off UG2 alignment: Adjust the unit to the following settings, R-Cut=32, G-Cut=32, R-Drv=32,

G-Drv=32, B-Drv=32. Place the set into an ageing test for >15 minutes.Activate
the UG2 display adjustment mode. Adjust the SCREEN VOLUME until the
indicator on the unit will light up.

White Balance: Adjust after performing UG2 CUT OFF adjustment. Place the set into an ageing

test for >10 minutes. Receive the gray scale from a pattern generator. Set the
colour balance to normal position. Activate the adjustment mode, press the
UP/DOWN button on the remote to select R-Cut, G-Cut, R-Drv, G-Drv, and B-Drv
and adjust accordingly using +/- button on the remote to whiten. Perform the
adjustment until the white colour seems white.

4