TX-21AT1P - Panasonic TV Service Manual (repair manual)

tx-21at1p service manual
Model
TX-21AT1P
Pages
22
Size
2.64 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / COLOUR TELEVISION
File
tx-21at1p.pdf
Date

Read Panasonic TX-21AT1P Service Manual online

ORDER No. 03-SM-004
Service Manual
Colour Television 
TX-21AT1P 
Z8T  Chassis
SPECIFICATIONS
 
Power Source:
 
   220-240V 
a.c., 
50Hz 
 
Power Consumption:
  
48W   
 
Stand-by Power  
Consumption:
 
   0,8W 
 
Aerial Impedance:
  
 
75
Ω unbalanced, Coaxial Type 
 
Receiving System: 
 
PAL B/G, PAL D/K ,PAL-60 
 
 
SECAM B/G, SECAM D/K 
  
M.NTSC 
(AV) 
 
 
 
 
 
 
 
NTSC (AV only) 
 
Receiving Channels:   
 
VHF E2-E12 
 
VHF H1-H2 (ITALY) 
VHF A-H (ITALY) 
 
VHF R1-R2 
VHF R3-R5 
 
VHF R6-R12 
UHF E21-E69 
 
CATV (S01-S05) 
CATV S1-S10 (M1-M10) 
CATV S11-S20 (U1-U10) 
CATV S21-S41 (HYPERBAND) 
 
Intermediate Frequency: 
Video/Audio  
Video  
38,9MHz 
Audio  
32,4MHz, 
33,4MHz 
Colour 
 
34,47MHz (PAL),  
 
 
34,5MHz (SECAM),  
  
34,65MHz 
(SECAM) 
 
 
Terminals: 
 
AV1 IN  
 
 
 
 
Video (21 pin)  1V p-p 75
Ω 
       Audio 
(21 
pin) 
500mV 
rms 
10k
Ω 
       RGB 
(21 
pin) 0,7V 
p-p 
75
Ω 
AV1 OUT   
 
 
 
Video (21 pin)  1V p-p 75
Ω 
 
      Audio (21 pin)  500mV rms 1k
Ω 
 
 
AV FRONT  
 
 
Audio (RCAx1)   
500mV rms 10k
Ω 
      Video 
(RCAx1) 
 1V 
p-p 
75
Ω 
 
High Voltage:
   
 
27kV ± 1kV 
 
Picture Tube:
 
A51ERF135X71 51cm 
 
Audio Output:
 
1 x 5W RMS, 1 x 10W MPO 
 
8
Ω Impedance 
 
Headphones:
 
8
Ω Impedance 
 
Accessories  
supplied : 
Remote Control 
 
2 x R6 (UM3) Batteries 
 
Dimensions:
   
Height: 
    476mm 
Width: 
    524mm 
Depth: 
    473mm 
 
Net weight:
   22kg 
 
 
 
 
 
Specifications are subject to change without notice. 
Weights and dimensions shown are approximate. 
 
NOTE:    This Service Manual should be used in conjunction with 
the Z8 Technical guide. 
 
 
 
 
 
 
CONTENTS
SAFETY PRECAUTIONS ......................................................................................................................................................... 2 
SERVICE HINTS ...................................................................................................................................................................... 3 
ADJUSTMENT PROCEDURE AND SELF-CHECK .................................................................................................................. 4 
WAVEFORM PATTERN TABLE............................................................................................................................................... 5 
ALIGNMENT SETTINGS .......................................................................................................................................................... 6 
BLOCK DIAGRAMS.................................................................................................................................................................. 7 
PARTS LOCATION................................................................................................................................................................. 10 
REPLACEMENT PARTS LIST................................................................................................................................................ 11 
SCHEMATIC DIAGRAMS....................................................................................................................................................... 17 
CONDUCTOR VIEWS ............................................................................................................................................................ 20 
 
SAFETY PRECAUTION
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 28kV 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 2k
Ω 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 previous measurements. 
 
 
6.  The potential at any point should not exceed  
1,4 Vrms. 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
WATER PIPE
(EARTH)
TO INSTRUMENT'S EXPOSED
METALLIC PARTS
Fig. 1.
2k 10 Watts
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 28kV 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: 
  27kV ± 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. 
2
SERVICE HINTS 
How to remove the rear cover 
1.  Remove the 5 screws as shown in 
Fig.2. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
LOCATION OF CONTROLS 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Screws
 
Screws 
 
Fig.2. 
 
3
Fig. 3 
Y-Board 
E-Board 
Focus Screen 
 ADJUSTMENT PROCEDURE 
Item / Preparation 
Adjustments 
+B SET-UP 
1.  Receive a Greyscale signal. 
2.  Set the controls : 
 
Brightness   Minimum 
 
Contrast     Minimum 
 
Volume     Minimum 
 
Confirm the following voltages. 
 
B1 3,3 
 
 
 ± 0,3V   B13  -16      ±  1V 
B2 190 ± 
 
10V  B14 27,5 ± 1,5V 
B3 
16   
±  1V        
B15 28 
  ± 1,5V 
B4 
10   
±   1V  
 
B16  13      ±  1V 
B8 5  ± 
 
0,3V   B17  8     
±  1V 
B11 127  ± 
 10V    B18  5   ± 0,3V 
   
 
 
 
CUT OFF / Ug2 Test 
1.  Receive a Greyscale signal. 
2.  Degauss the tube externally. 
3.  Set the TV into Service Mode 1. 
4.  Select Cut off mode. 
 
 
Set Contrast on maximum, set Brightness on center, switch 
on AV mode. 
Enter Service mode. Set Sub-Brightness to 31. Select Ug2 
Test. Press "+" and adjust screen Vr  till sharp vertical line is 
visible and LED switches off. Then reduce screen Vr till LED 
is just switched on. 
 
 
SELF CHECK
Self-check is used to automatically check the bus lines and hexadecimal code of the TV set.To enter Self-Check mode, press 
the STATUS         button on the remote control and at the same time press the down (-/v) button on the customer controls at 
the front of the TV set. To exit Self Check, switch off the TV set at the power button.
OPTION 1  E0  
 
 
OPTION 2  02  
 
 
If the CCU ports have been checked and found to be incorrect or not located then " - - " will appear in place of "O.K.".
Service Aids 
To aid in the service of our current chassis there are a number of Service Aids which have been made available. 
• 
LUCI
 interface kit (Linked Utility Computer Interface) 
Part number: TZS6EZ002 
This contains interface and cables for connecting TV service connector and a PC as well as diagnostic software. As new 
models are introduced upgrade software will become available. 
• 
VICI
 (Visual Interactive Computer Information) 
These C.D.'s contain multimedia documentation providing quick access to service information. 
Part No. TZS7EZ006, TZS7EZ005, TZS8EZ001 & TZS9EZ001 
1. Service Manuals 
2. Instruction Books 
3. Technical Information 
• 
TASMIN
 (Technically Advanced System for Multimedia Interactive Notes) 
As well as providing a first step towards more interactive training this product also achieves quick access to Technical 
Information. 
4
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Download Panasonic TX-21AT1P Service Manual (Repair Manual)

Here you can read online and download Panasonic TX-21AT1P Service Manual in PDF. TX-21AT1P service manual will guide through the process and help you recover, restore, fix, disassemble and repair Panasonic TX-21AT1P TV. Information contained in service manuals typically includes schematics / circuit diagrams, wiring diagrams, block diagrams, printed wiring boards, exploded views, parts list, disassembly / assembly, pcb.