Panasonic TC-21PM30R Service Manual

ORDER NO. MTV 0010147C3

Service Manual

Colour Television

TC-21PM30R

MX-7 Chassis

Specifications

Power Source :

Power Consumption :

Aerial Impedance:

Receiving System : Receiving Channels : High Voltage :

VHF 2-12 (PAL/SECAM B,K1) at zero beam current

UHF 21-69 (PAL G,H,I/SECAM G,K,K1)

CATV S1-S41(OSCAR)

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

Colour 33.57 MHz (PAL)

AC AUTO 110-240V, 50/60Hz

86W Audio InApprox, 400mVrms

75 unbalanced Audio InApprox, 400mVrms

Ω

Coaxial type Monitor Out :Video Out1 Vp-p 75

17 System

0-12 (PAL B AUST) 1-9 (PAL B N.Z) 1-12 (PAL/SECAM D) 51cm (21 inches) 1-12 (NTSC M JAPAN) Measured diagonally, 90 deflection 2-13 (NTSC M U.S.A)

28-69 (PAL B AUST) 13-57 (PAL D,K) 13-62 (NTSC M JAPAN) 14-69 (NTSC M U.S.A)

1-125 (U.S.A CATV) Width : 600 mm C13-C41(JAPAN) Depth : 484.4 mm S21-S41 (HYPER) Z1-Z37 (CHINA)

32.0 MHz (I) / 32.5MHz (M) mate.

33.6 MHz (SECAM)

32.5 MHz (B,G)

33.75 MHz (SECAM)

34.42 MHz (NTSC)

Video / Audio Terminals :

FAV In : Video In 1 Vp-p 75

RAV In : Video In 1 Vp-p 75

Audio OutApprox, 400mVrms

28.0 kV ( +/- 1.0 )

Picture Tube :

Audio Output :

Dimensions :

Mass :

23.4 kg

2000 Matsushita Electric Industrial Co., Ltd.

XA51LSK955X-A

3.5W x 2 = 7W

Height : 473.6 mm

Ω Ω

Ω

Panasonic

WARNING

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.

Contents

.Safety Precautions ........................................................................................ 2

.MX-7 Chassis Block Diagram .................................................................... 4

.Service Hints ................................................................................................. 5

.Adjustments ...................................................................................................7

.Conductor Views ...........................................................................................13

.Schematic Diagrams .................................................................................... 15

.Parts Location ...............................................................................................18

.Replacement Part List ................................................................................. 19

Safety Precautions

General Guide Lines

1. It is advisable to insert an isolation transformer in the AC supply before servicing this hot chassis.

2. When servicing, observe t he origina l lead dres s, espec ially the lead dress in the high v ol tage circ uits. 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 no t to be use d fo r a long period of time, unplug the power cord from the AC cord outlet.

5. Potential, as high as without the rear co v er involves the danger of a shock h azard f rom the re ceiver po wer sup ply. Servicing should not be attempted by anyone who is not th oroughly famili ar with the precau tions 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 mak e the fo llo wing l eakage cur rent ch ecks to pre v en t the cust omer from be ing e xposed to shock hazards.

Leakage Current Cold Check

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 resist ance value, with an ohmmeter, bet ween t he jumpe r AC plug and each exposed metallic 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 2 0 Mohm.When the exposed metal doe s not have a return path to th e cha ssis, the reading must be infinite.

kV. is present when this receiver is in operation. Operation of the receiver

28.0

Leakage Current Hot Check ( Fig.1 )

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 measurement 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

X-Radiation

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 28.1kV without causing X-Radiati on. Note : It is impo rtant 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 28.0(+-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.

MX-7 Chassis Block Diagram

Service Hints.

Service Position for E-Board

1. Remote the back cover.

2. Stand the TV set as shown in fig. 7.

3. Remove the A-Board from the TV set by pulling the main board out as shown in figure 7.

Pull out this way

Fig.7

Factory mode adjustment :

How To Set : To set the Factory mode, press Volume 0 dac on the TV and Timer Setting 30min

on the remote control and press Volume (-) Down button on the TV together press recall on the remote control. CHK should appear on right of TV screen. To move from CHK1 to CHK2 mode, etc, please follow below rotation :

To Set Self-Check : Press the volume down button on TV than press the off timer button on

remote control.

Adjustment for White Balance

Preparatio n :

1. Receive the white balance pattern and aging should have been performed over 30 minutes.

2. Set the picture menu to to DYNAMIC NORMAL.

3. Degause the CRT face.

4. Fix the CRT colour analyzer receiver unit to CRT face.

Adjustment of Low Light.

1. Adjustment Sub Bright, so that Y = 6.3 +- 1.0nit.

2. Adjust R-CUT OFF, so that X = 0.235 +- 0.01nit.

3. Adjust G-CUT OFF, so that y = 0.235 +- 0.01nit.

Adjustment of High Light.

1. Adjust Sub Bright, so that Y = 270 nit.

2. Adjust R-Drive, so that X = 0.265 +- 0.01nit.

3. Adjust B-Drive, so that y = 0.265 +- 0.01nit.

Adjustment for CRT CUT OFF.

Preparatio n :

1. Connect ocilloscope probe to TPL7.

2. Screen VR min.

3. Set the data Sub Bright , Bright.

4. In service Mode at ‘Bright’ dac press [5] in factory mode to enter vertical line and adjust by volume down or up button.

5. Adjust “Screen VR” until 1-H Line appears.

130V

Adjustment Procedure

Item / Preparation Adjustment Procedure

+B Voltage

1. Operate the TV set. Confirm the DC voltage at the indicated test points, as follow :

2. Set control as follow : TPA 12 : 141.2 +- 0.8V TPA 21 : 215 +- 15V

Brightness ..... minimum TPA 11 : 8 +- 1V

Contrast ........ minimum TPA 10 : 5 +- 1V

RF AGC

1. Receive a colour bar signal at an 1. Select “RF A GC” indi cation in CHK 2 , on Screen

RF level of 64(+0-1)dBU with 75 by remote control at factory mode. loaded.

2. Connect digital multimeter to RF AGC 2. Set RF AGC by using remote control volume (+)

at Tuner. or volume (-) button until voltage AGC at Tuner

High Voltage

Ω

reach 2.7 +- 0.1V.

3. Increase RF signal strenght by 2dB, confirm AGC at Tuner voltage drop.

1. Receive the crosshatch pattern. 1. Connect a DC voltage meter to TPA 12 and confirm the +B voltage is 141.2 +- 0.8V.

2. Set to 0 Beam . 2. Connect a high frequency voltmeter to heater and

Screen VR ..... minimum confirm that voltage reads 6.3+- 0.24 (VRMS).

Contrast ....... minimum 3. Normalize the brightness and contrast.

Item / Preparation Adjustment Produre

Connect oscilloscope probe to TPA32 (R-OUT) with 10Kohm series resistor. Connect a short jumper between TPA 10 1. Adjust Sub-Tint so that No.2,3 and 4 becomes and TPA 20. level waveform is similiar to Fig. 10. Press Main Menu and Set system to 2. Confirm phase at Tint is changes more than Use AV-NTSC (3.58MHz). +/- 30 by Tint control.

DYNAMIC ....... Normal 3. Confirm that colour level is maximum when

colour DAC is adjusted to maximum position.

Note:Use Remote control only when adjusting user mode

to Sub-Tint.

0.5a 7 8 9 10

1 2 3 4 5 6

Fig. 10

Pal Colour

1. Receive the PAL B/G studio colour bar pattern, and adjust local frequency at the best tuned position.

2. Pic Menu : Dynamic Normal , Confirm Contrast - 63 , Sub Contrast - 21.

3. Channel colour set ----------- STD.

4. Connect TPA 10 to TPA 20.

5. Set (A) to 2.3 +- 0.2V by BRT (CHK2) Fig. 1.

Adjustment

1. Connect oscilloscope probe to TPA 31 (G OUT) with 10k series resistor and adjust Contrast so that (B) as in Fig.1 is 2.8 +- 0.1V.

2. Adjust ‘Sub Colour’ so that waveform as in Fig.1 (1) 2.55 +- 0.1V.

3. Connect oscilloscope probe to TPA 32 (R OUT) with 10k series resistor and confirm waveform as in Fig.2 is (2).2.7 +- 0.4V

Fig. 1 Fig. 2

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