TX-21PM30T - Panasonic TV Service Manual (repair manual)

Colour Television

Power Source : AC AUTO 110-240V, 50/60Hz

FAV In :  Video In 1 Vp-p 75           

Power Consumption : 86W

Audio In Approx, 400mVrms

RAV In : Video In 1 Vp-p 75           

Aerial Impedance:75    unbalanced

Audio In Approx, 400mVrms

 Coaxial type

Monitor Out :Video Out1 Vp-p 75        

Audio OutApprox, 400mVrms

Receiving System : 17 System
Receiving Channels :

High Voltage : 28.0 kV ( +/- 1.0 )

VHF

2-12  (PAL/SECAM B,K1)

 at zero beam current

0-12  (PAL B AUST)
1-9

(PAL B N.Z)

Picture Tube : A51LSK955X-A

1-12  (PAL/SECAM D)

51cm (21 inches)

1-12  (NTSC M JAPAN)

Measured diagony, 90  deflection

2-13 (NTSC M U.S.A)

 

UHF

21-69 (PAL G,H,I/SECAM G,K,K1)
28-69 (PAL B AUST)

Audio Output : 3.5W x 2 = 7W

13-57 (PAL D,K)
13-62 (NTSC M JAPAN)

       

14-69 (NTSC M U.S.A)

CATV

S1-S41(OSCAR)

Dimensions :  Height :  473.6 mm

1-125 (U.S.A CATV)

Width  : 600.0 mm

C13-C41(JAPAN)

Depth  : 484.4 mm

S21-S41 (HYPER)
Z1-Z37   (CHINA)

Mass : 23.4 kg

Intermediate Frequency :
Video

38.0 MHz

Specifications are subject to change without 

Sound

31.5 MHz (D,K) / 32.5MHz (B,G)

notice.Mass and dimensions shown are approxi

32.0 MHz (I) / 33.5MHz (M)

mate.

Colour

33.57 MHz (PAL)
33.6 MHz (SECAM)
32.5 MHz (B,G)
33.75 MHz (SECAM)
34.42 MHz (NTSC)

Panasonic

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This service literature is designed for experienced repair technicians only and is not designed for use by the
general public. It does not contain warning cautions to advise non-technical individuals of potential dangers in
attempting to service a product. Product powered by electricity should be serviced or repaired only by 
experienced professional technicians. Any attempt to service or repair the product or products dealt with in this
service literature by anyone else could result in serious injury or death.

WARNING

!

1. It is advisable to insert an isolation transformer in the AC supply before servicing this hot chassis.
2. When servicing, observe the original lead dress, especially the lead dress in the high voltage circuits. If 

a short circuits is found, replace all parts which have been overheated or damaged by the short circuit.

3. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers, 

shields, and isolation R-C combinations, are properly installed.

4. When the receiver is not to be used for a long period of time, unplug the power cord from the AC cord 

outlet.

5. Potential, as high as 28.0kV. is 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 thoroughly familiar with the precautions necessary when 
working on high voltage equipment. Always discharge the anode of the picture tube to the receiver 
chassis before handling the tube.
After servicing make the following leakage current checks to prevent the customer from being exposed 
to shock hazards.

1. Unplug the AC cord and connect a jumper between the two prongs on the plug.
2. Turn on the receiver’s power switch.

Measure the resistance value, with an ohmmeter, between the jumper AC plug and each exposed metal-
lic cabinet part on the receiver, such as screw heads, aerials, connectors, control shafts, ect. When the 
exposed metallic part has a return path to the chassis, the reading should be between 4 Mohm and 20 
Mohm.When the exposed metal does not have a return path to the chassis, the reading must be infinite.

1. Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.
2. Check a 2 kohm non-inductive resistor and an AC/DC current meter, in series with each exposed 

metallic part on the receiver in turn and an earth such as a water pipe.
The current from any point should not exceed 0.7 mA peak AC or 2mA DC. In the case of a measure-
ment being outside of these 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.

Fig. 1

Warning :

The potential sources of X-Radiation in TV set are the EHT section and the picture tube. When using a picture tube test jig for
service, ensure that jig is capable of handling 28.0kV without causing X-Radiation. Note: It is important to use an accurate
periodically calibrated high voltage meter.

 1. Set the brightness to minimum.

 2. Use the remocon to get into Service Mode.

 3. Measure the EHT. The meter reading should indicate 27.0(±1.0)kV. If the meter indication is out of tolerance, immediate service

and correction is required to prevent the possibility of premature component failure.

 4. To prevent the possibility X-Radiation, it is essential to use the specifield picture tube, if service replacement becomes

necessary.

3