DOWNLOAD Panasonic CT-34WX50 Service Manual ↓ Size: 10.31 MB | Pages: 58 in PDF or view online for FREE

- 4 -

To monitor the high voltage, the positive DC voltage from the
cathode D512 is applied through R788 and other resistors to
pin 3 of IC475, which is the input terminal of the X-ray Pro-
tection Circuit. The voltage at pin 2 of IC457 is adjusted by
R720 at 5.83 +0.01, -0.02 voltage. Under normal conditions
this voltage is insufficient to activate the X-ray Protection Cir-
cuit.

If the voltage at pin 3 of IC457 increases over the voltage at
pin 2 of IC457 increases and causes the X-ray Protection to
activate. Then it causes the shut down works.

In the process described above, the voltage at pin 3 of IC457
is compared with the voltage at pin 2 of IC457.
if excessive beam current is drawn, the voltage at oin 3 of
IC457 increases. When the voltage at pin 3 of IC457 over the
voltage at pin 2 of IC457, the voltage at pin 1 of IC457
becomes “high” and feeds into Base of Q401, and the volt-
age at Corrector of Q401 becomes “high” and feeds into pin
38 of micro-controller IC5508 through R5618.
The micro-controller then turns off Q802, causes the AC
power relay RL001 to unlatch and turns off the receiver.

To prevent any adjustment on the sealed control after final
adjustment is done at factory. If the sealant are removed
for any reason, the control is damaged at same time.

1. Silicone-Type T8C1710201H, manufactured by Shin-Etsu 

Chemical Co., Ltd. (Japan)

2. Hard ABS tube-Type TMMX004

No tool is required.

1. Place the hard ABS tube on the designated sealed con-
trol,

as shown in Figure a.

Figure a.

2. When the tube is gently pressed all the way down and

adhere to the P.C.B., apply the silicon into the hard ABS
tube and form hemisphere like object on the top of tube, a

shown in Figure b.

Figure b.

6

1

+

-

X-Ray Detect

38

7

1

2

3

12V

R809

Q802

R810

R5568

IC5508

R5618

R770

C481

R773

R720

R522

R788

R521

D512

FBT T551

R520

C528

R721

12V

EHT

CRT

IC457

AC POWER RELAY

RL001

Comparator Ref.

Comparator out

Comparator in

Silicone

- 5 -

When symptoms like "the power fails sometimes" or "sometimes there is no picture and/or sound" can not be confirmed at the
time of servicing, the self-check function can be used to confirm the occurrence and to find the defective circuit.
In case of "power failure", flashing of the "VIDEO IN" indication (red) at the front of the unit can be used to narrow down the +B
line.

<Indication method>
Press the SLEEP button on the 
other model TV remote control 
simultaneously with the 
"VOLUME -" button on the unit.
(The display will be switched to 
the screen of VIDEO 1 and the 
screen shown on the right will be 
displayed.)

<Return to the normal screen>
Return to the normal screen will
be made by POWER or any other
remote control operation.

Note:
This model’s remote controller
don’t have sleep Button.

[VOLUME-] Button

H10

No receive for Main picture.

Exchange TNR001.

A-Board

H13

No receive for Sub picture.

Exchange TNR003.

H14

BEE and LED does not work.

Exchange IC5002.

H21

No sound.

Exchange IC2401.

H90

Picture and Sound can not be adjusted.

Exchange IC5001.

H93

No sound.

Exchange IC5003.

H30

TV/AV switching is not possible.

Module exchange

H-Module

H33

No video from component (color differnce) input.

H39

H31

Vector Detector does not operate.

Module exchange

DG-Module

H32

Sub picture is No color (W/B).

H36

Main picture is No color (W/B).

H45

The split screen function does not operation.

H94

Picture is not stationary.

H34

Abnormal sparpness.

Module exchange

AG-Module

H37

VM does not work.

H38

No video, defective OSD.

H51

Horizontal and vertical synchronization not stationary.

Module exchange

Q-Module

hyperOne

DG

IC1310

IC4504

IC4506

IC4513

IC4514

OK H94

OK H36 

OK H45

OK H32

OK H31

Primary IIC

AG

IC2503

IC2504

IC2505

OK H34

OK H37 

OK H38

Secondary IIC

A

IC2401 OK H21

Q

IC452

OK H51

A

IC5001

IC5002

IC5003

TNR001

TNR003

OK H90

OK H14 

OK H93

OK H10

OK H13

H

IC3007

IC3012

IC3013

OK H33

OK H39 

OK H30

Check result of IC
"OK" Normal
"NG" Abnormal

(Check IC or its nearby components)

- 6 -

 When an abnormality has occurred for a power supply line, the protection circuit (power supply protector/detection of abnormal
high voltage) operate and cuts the power supply. At this time, the defective line can be identified by the number of flashes (red) of
the "Power supply/function standby/video reception" indication at the front of the unit by means of the fault line which has oper-
ated the protection circuit.

Flashing

Flashing timing

Contents

Once

Twice

Three times

Four times

Five times

Six times

Seven times

Once

3 sec

No Light

Light

High voltage protect

+25V, +144V overcurrent
detection, vertical drive 
+15V voltage drop

DD module main voltage
drop

DD module sub voltage
rise

Voltage drop
(+3.3V/9V/+12V)

+25V, +144 V overcurrent 
detection

+5 V voltage drop

- 7 -

G-Board

A-Board

K-Board

P-Board

L-Board

DD-Module

CC-Module

H-Module

D-Board

U-Module

AG-Module

DG-Module

Q-Module

(See Note)

Note: When a non-serviceable board is determined to be 

defective, please replace the board and return the 
defective board to the factory.

TNPA1531

G-Board, Front terminal

TNPA1532

K-Board, LED

TNPA1536AB

L-Board, CRT Drive

TNPA1675

P-Board, AC Power

TNPH0306AF

D-Board, Power Deflection

TNPH0340

A-Board, Main

TNPA1520AC

DD-Module, DC DC

TNPA1523AB

Q-Module, V-Deflection

TNPA1524

AG-Module, Analog Core

TNPA1525AD

U-Module, MPU

TNPA1526

DC-Module, Digital Core

TNPA1676

CC-Module, C.C./V chip

TNPA1710

H-Module, AV switching