Panasonic TC-P50UT50, TC-P50ST50 Service Manual

2012 Plasma TV Troubleshooting Guide

2012-Plasma FHD TV – ST Series (15

Applies to models:

TC-P50ST50

TC-P50UT50

Generation)

National Training Department

Panasonic Consumer Marketing

Company Of North America

TTG120313CP120417

Important Information

• To avoid the unnecessary replacement of multiple PC boards, please read this before

beginning to repair this unit.

• Do not use any service documentation oth er than the one designed for this particular model.

• Techniques used on previous models may not necessarily apply to the model you are

working on.

• For accurate diagnosis during troubleshooting, do not skip or alter the order of steps on the

guide.

Slide 2

SOS Precautions

When an abnormality occurs in the unit, the “SOS Detect” circuit is triggered and the TV shuts down. The power LED on the front panel will flash a pattern indicating the circuit that has failed.

Cautions:

If the power LED continues to blink even after the TV is unplugged, press and hold the power switch on the TV for a few seconds until the LED turns off.

Some steps require removal of connectors and sometimes PC boards removal. Do not allow the TV to run for more than 30 seconds while connectors or boards are disconnected.

NOTE: When taking voltage reading, place your meter’s probe on the test point or pin indicated before connecting the TV to the AC line. The voltage you intent to measure may only appear for a brief moment.

Warning: The Vsus line has large capacitors that hold the charge for some time even after the TV has been turned off and

unplugged. When disconnecting P2/SC2 or P11/SS1, bleed the remaining charge of the Vsus before reconnecting the cable. Use a 500 ohms/ 5W (At least) resistor to discharge the Vsus line before reconnecting P2/SC2 or P11/SS11.

Slide 3

Power LED Error Code Definition (1 of 2)

POWER LED

ERROR

CODE

1 BLINK

2 BLINKS P15V form the P board

3 BLINKS

4 BLINKS

6 BLINKS SC Energy Recovery Circuit

7 BLINKS

8 BLINKS

CIRCUIT MONITORED

Panel Information SOS

Incomplete or interrupted

Boot Program execution of

PEAKS IC (IC8000).

Power Supply output

voltages

Scan Drive Circuit and

Connection between the SC

board and the SC board.

Sustain Drive Circuit and

Connection between the SS

board and the Panel.

CONDITIONS TRIGGERING

THE SHUTDOWN

Communication problem A Missing P15V

P15V is not been generated by the P board. Wrong diagnostic by the A board Shorted P15V Missing F15V Wrong diagnostic by the A board Vsus Over Voltage Condition. P15V Shorted while in operation. Wrong diagnostic by the A board An increase or reduction of the Energy Recovery Circuit output (MID). Shorted SUB5V. Wrong diagnostic by the A board. Missing or shorted Vsus. Abnormality of the scan circuit output, the 15V_F, the scn_pro, and Vscn circuit. Loose or open Connection between the SC board and the SC board (SC41, SC42, SC46). Open or loose connection between connectors SC2/P2 Wrong diagnostic by the A board Defective panel Abnormality of the sustain drive circuit. Open or loose connection between the SS/SS2 Boards. and FPCs from the panel (SS52 – SS54 – SS55 – SS57). Open or loose connection between connectors C10/C20 or C26/C36. Wrong diagnostic by the A board

LIST OF BOARDS POSSIBLY CASUSING THE FAILURE

#1 Suspect #2 # 3 Occasionally

P A

A P

P A

SC A C

SU/SD SC SS A/Panel

SS A C3 Panel

Not Often

Slide 4

Power LED Error Code Definition (2 of 2)

POWER LED

ERROR

CODE

9 BLINKS

10 BLINKS SUB3.3V_Sense (OVP)

12 BLINKS Audio Amp. Circuit

13 BLINKS

CIRCUIT MONITORED

Discharge Control Circuit

DDC (IC9300)

IC8000 Internal Communication

CONDITIONS TRIGGERING

THE SHUTDOWN

Failure of IC9300 Wrong diagnostic by the A board

Over Voltage Condition of SUB5V or SUB3.3V Wrong diagnostic by the A board.

Defective Speaker/Subwoofer Pinched Speaker Wire Wrong diagnostic by the A board

Defective A board A

LIST OF BOARDS POSSIBLY CASUSING THE FAILURE

#1 Suspect #2 # 3 Occasionally

Speakers/

Subwoofer

Not Often

Slide 5

Protection Circuit Block Diagram 1 of 2 (TC-P50ST50)

P15V

SUB3.3V

A20

SC_SOS6

FFC_OFF_DET(6)

SC_SOS7

A33

SS_SOS8

SOS_DCC_S (9)

A20

SC_UHZ

Missing 2 Blinks

Shorted 3 Blinks

Missing 3 Blinks

Shorted

At plug-in

IC5000

REG

(STB3.3V)

RESET

1314

(If no signal, Discharge Reset

6/8 blinks)

179

P15V

Det. Circuit

P15V

Q9201

(Analog output)

6 – 9 blinks

Normal : all input = “L”

(output = “L” )

DRVRST

D_UHZ

C24

M28

IC9300

AG3

W28

P3.3V

Q9201

2 blinks

SOS

PANEL_SOS

(If no 3.3V in C1/C2-PCB, Discharge Reset

6/8 blinks)

3.3V_DET

A31

A32

PDP_DRVRST

SOS

TC-P**ST50/UT50

AE20

IC8000-1

AD15

Peaks

LD4

AD16

Standby

uCOM

System

uCOM

AF16

(TNPH0989**)

2 Blinks

if P15 is

missing

SUB3.3V

Det. Circuit

SUB3.3V

3 blinks

3 Fast

Blinks

At plug-in

if SUB3.3

is missing

Slide 6

Blink Code/Voltage Condition (TC-P50ST50 - TC-P50UT50)

No. of Blinks

Voltage Condition

TC-P50UT50 TC-P50ST50

Missing 2 Blinks 2 Blinks

P15V

SUB3.3V

SUB5V

No power. The LED turns o n

Shorted

Missing 3 Fast Blinks at Plug-in 3 Fast Blinks a t Plug-in

Shorted 3 Fast Blinks at Plug-in 3 Fast Bli nks at Plug -in

Over Voltage

Missing 3 Fast Blinks at Plug-in 3 Fast Blinks a t Plug-in

Shorted 6 Blinks After 11sec. 6 Blinks After 11sec.

Over Voltage

briefly and then it goes off

immediately

Dead. Power LED never

turns on

Dead. Power LED never

turns on

3 Fast Blinks

10 Blinks

Slide 7

Protection Circuit Block Diagram 2 of 2 (TC-P50ST50)

SUB5V &

SUB3.3V

OV Det.

Circuit

SUB5V

SUB3.3V

IC4900

IC4901

Audio

AMP

Audio

AMP

SUB3.3V

Normal=“H”

Q8771

STB3.3V

Q8771

10 blinks

SOUND_SOS

12blinks

TC-P**ST50/UT50

(TNPH0989**)

10 Blinks if

SUB5V or

SUB3.3V is

too high

AA15

SOS

IC8000-2

Peaks

LD4

AD19

Standby

uCOM

SUB5V

Missing 3 Fast

Shorted 6 blinks

after 11 sec.

Over Voltage 10 blinks

Emergency : 13 blinks IROM error : quickly 3 blinks

blinks at

plug-in

FAN_SOS

(11blinks)

ALL_OFF(P_SOS4)

4 blinks

System

uCOM

AE15

Slide 8

Troubleshooting 1 -9 -10 - 13 Blinks Failure

Blink

List of boards likely to cause this symptom

Code

No.1 No.2 No.3 No.4

1 A Board

9 Blinks A Board 10 Blinks A Board 13 Blinks A Board

When 1, 9, 10, or 13 blinks occur, replace the A board

Slide 9

Troubleshooting 2 Blinks Failure (TC-P50ST50)

Find information for TC-

P50UT50 on the next slide)

Start Here

Place the positive lead of a voltmeter at pin 13

of connector P6 while the black lead is

connected to ground (Chassis ground). Plug in

the TV and turn it on

Blink

List of boards likely to cause this

symptom.

Code

No.1 No.2 No.3 No.4

2 Blinks P A

Replace the A

board

Yes

Does 15V

appears

momentarily

on pin13 of

CN P6?

Replace the P

board

Slide 10

Troubleshooting 2 Blinks Failure (TC-P50UT50)

Blink Code

List of boards likely to cause this

symptom.

No.1 No.2 No.3 No.4

2 Blinks P A Panel/C2

Place the positive lead of a voltmeter at

pin 13 of connector P6 while the black lead

is connected to ground (Chassis ground).

Plug in the TV and turn it on

Start Here

Find information for TC-

P50ST50 on the previous

slide)

Unplug the TV. Check the resistance between TP201 (P3.3V)

on the C2 board and chassis ground.

Yes

Does 15V appears

momentarily on

pin13 of CN P6?

Yes No

Defective

Panel and/or

C2 board

Replace the P

board

Is there a

short

circuit?

Replace the A

board

Slide 11

Troubleshooting 3 Fast Blinks Failure (TC-P50ST50)

List of boards likely to cause this symptom. Blink

Code

3 Blinks A P SS/SC

No.1 No.2 No.3 No.4 No.5

Bluetooth

Module

With the TV still disconnected, remove connector

A6 from the A board and perform the same

resistance check on pin 13 of connector P6.

Is there a short circuit

or a resistance lower

than 1 Kilo-ohm?

Yes

Reconnect SS33 and remove connector

A31 and A32 from the A board and

check for short circuit or low resistanc e

on pin 13 of connector P6.

Replace the P

board

than 1 Kilo-ohm?

Replace the SS

board

Yes

Is there a short

circuit or a

resistance lower

Start Here

Unplug the TV. Check for short circuit or low

Panel

resistance between pin 13 of connector P6

and ground (Chassis ground).

Is there a short

Yes

circuit or a

resistance

lower than 1

Kilo-ohm?

Reconnect SC20 and remove

connector SS33 from the SS board

and check for short circuit or low

resistance on pin 13 of connector P6.

Unplug the blue-

tooth module. If the

blinking stops,

change the blue-

tooth module

Reconnect A6 and remove connector SC20

from the SC board and check for short circuit

or low resistance on pin 13 of connector P6.

Yes

short circuit or

a resistance lower than 1

Replace the A

board

Is there a

Kilo-ohm?

Replace the A

board

Yes

Is there a

short circuit or

a resistance lower than 1

Kilo-ohm?

If no short circuit is found on any of the C

boards, change

the panel

Replace the SC

board

Slide 12

+ 27 hidden pages