9th Generation Plasma Display Technical Information 1
The technicians have express their needs and we listened. This presentation has been developed especially for the technicians involved in the repair of our plasma televisions. We’ve gathered and analyzed your emails, questions, feedback, and requests. Based on this information, we have put together a presentation to fulfill your needs.
Topics • Power Supply/System Control Interaction • Boards Isolation • Understanding SOS Condition • Video Processing • Troubleshooting 3
9th Generation Plasma Display Television • What really happens when the TV is plugged in? 4
Sequence of Events when the TV is Plugged In When the Plasma TV is plugged in, there’re a few indications of normal operation. Knowing this will help us understand what’s going on with the unit when an abnormality occurs. 5 1. There is a click from the relays RL402 and RL403 when they are activated. 2. The LED in the Optical Jack inside the DT board turns on for approx. 4 seconds. 3. Immediately after that, one of the Tuner LEDs (Right) turns on (Solid Red) for approximately 20 seconds. 4.
Standby Block (Part 1) 6
Standby Block (Part 2) 7
Power Supply (Standby Circuit) 8
Power Supply (Standby Circuit) SS34 Connector 9
STB5V Distribution 10
STB5V Test Point (P board) 11
STB5V Test Point (PA board) 12
Power Supply (Standby Circuit) Tuner SUB ON = Command to turn the relays on.
F-STB-ON (Primary) T404 H H H L L 14 H
F-STB-14V and PFC Test Points 15
F-STB-14V H L 16
SUB-Voltages Output From the PA Board 17
PA Board Test Points 18
Power On/Off Operation 19
Power Off 20
Power On 21
Power Supply Secondary Circuit (1) L 22 H
Power Supply Secondary Circuit (2) 23
Power Supply Connectors 24
PA board Circuit Explanation 25
Main-Voltages Output From the PA Board 26
No Power Troubleshooting Chart Can the click sound from the relays be heard after the TV is plugged into the wall outlet? No Yes Is there 5V at pin 1 of connector PA40 on the PA board? No Yes Is there 2.5V at pin 13 of connector P25 on the P board? Yes Replace the P Board. Wait for approx. 20 seconds after applying AC to the TV. Then turn the power on. Replace the P Board. Can the click sound from the relays be heard while attempting to turn the power on? No Replace the DG Board.
Shutdown Detect Circuits Understanding how the SHUTDOWN circuit works SOS 28
What will normally cause the TV to shut down? • A short circuit on any of the voltage lines • An over-voltage condition • Abnormality in the Control Drive Pulse circuit (SC, SU, SD, and SS boards) 29
Cases When Missing Voltages Can Cause the TV to Shut Down • Missing the source voltage to the PA board (STB14V) from the P board • Missing output voltage from the PA board to the DG board.
Cases When Missing Voltages Can Cause the TV to Shut Down If the SUB 5V, SUB 9V or MAIN 3.3V is missing on the DG Board, the unit goes into shutdown. The power LED blinks ten times. The voltages are monitored on the DG board by the MPU, IC1103. 31 TPM3.3V MAIN 3.
TV Shutdown due to Over-voltage or Short Circuit This could happen if there’s a short circuit in one of the B+ lines from the PA board, an over-voltage condition, or missing STB 14V from the P board.
PA Voltage Output If any of the SUB or MAIN voltages that are highlighted on the DG Board is missing, the unit goes into shutdown. The power LED blinks ten times. If any of the voltages created on the PA Board is excessive or shorted, the unit goes into shutdown. The power LED blinks ten times.
TV Shutdown due to Over-voltage or Short-circuit The base of Q5642 being low indicates a short circuit in the Main 1.8V, Main 9V, or Main 5V output of the PA board. The base of Q5641 being low indicates a short circuit or an over-voltage condition in the NR14V, Main 1.8V, Main 3.3V, SUB 9V, SUB 3.3V or SUB 5V output of the PA board.
PA SOS Detect Circuit 35
PA-Board_Loss of Sub-Voltage Protection 36
PA Board_Over-Voltage Protection 37
To rule out the P board (Use a Peak Hold Meter for voltage reading) Note: Follow this procedure when the click sound of the relay can be heard after the unit is plugged in. If the relay does not click, check the STB 5V from the P board. If the STB 5V is missing, the P board may be defective. (If STB 5V is OK, the DG board may be defective.) • Disconnect connector P10 in the P board (Make sure the TV is unplugged).
DT, DG, H Board Assembly PA40 GND DT10 SL Connector WL Connector DG5 DG3 DG Board DT Board G51 Connector 39 H Board
Removal of Board Assembly To uninstall the board assembly, remove the 7 screws indicated by the red circles 40
Board Assembly (Hidden Connector) Hidden Connector DG51 41
Board Layout Without the Assembly
Power LED blinks 10 times When the power LED blinks 10 times right after the TV has been plugged-in into the AC line and the Power is OFF, the P, the PA, the DG, the H, or the DT may be defective. DT Board DG Board H Board The DT, DG, and H board are part of the assembly. For troubleshooting, the DT board must be removed.
To rule out the H board: Disconnect connector H40 and plug the TV into the AC line Note: If the Power LED stops blinking, the H board may be defective. If the power LED still blinks, See the next slide. Keep in mind, every time the H board is suspected to be defective, change both the PA and the H board at the same time before applying power to the unit.
Power LED blinks 10 times To rule out the DT board (Digital Tuner): 1. Remove the screws securing the DT board. Plug the TV into the AC line. 2. Note: If the Power LED stops blinking, the DT board may be defective. 3. Note: When the DT board is removed, the unit will power up with all functions disabled due to a lack of data communication. 4. If the Power LED still blinks, it is possible that the problem is the PA or the DG board.
10 Blinks Due to VSUS or VDA Voltage 46
Power LED blinks 5 times This is caused by abnormalities on the 5V line. This could also happen if the VDA voltage is shorted.
5V, VDA, Data, Scan, Sustain Distribution 48
5V Distribution 49
5V SOS Detection Circuit 50
Other Causes of 5V SOS • The Power LED could also blink 5 times if the VDA voltage is shorted [Normally by the Panel (de-multiplexer ICs)].
5V and VDA Distribution on the C Board 52
How to properly isolate the C boards • When the ribbon cables from the D board to the C boards are disconnected in order to isolate the C boards, the Power LED will blink 6 times. • The following circuit explains the reason why. • To properly isolate the C boards without having the Power LED blink, the test point TP9387 (Labeled TP9387 on the D board) should be grounded through a 1K resistor. • The VDA connector should be also disconnected.
Drive Reset Circuit 54
Drive Reset Circuit Test Point Foil Side of the D Board TP9387 is not shown on the board. The test point shown in these pictures is a substitute for TP9387. It is located on the foil side of the board. To make the ground connection, the board has to be removed.
15V Distribution 56
15V SOS Detection Circuit 57
Sound SOS Detection Circuit SOS N N SOS 58
Fan SOS 2 59
Fan SOS To determine if a fan is the cause of the 11 blinks of the power LED, simply use a peak-hold voltmeter to determine if pin 3 of the fan connector goes High before shutdown. If it does, the fan is defective. If it does not, check the other fans and the fan drive drive circuit.
D Board SOS Detect L 3.
DG Board SOS Detect 3.
Origin of Power LED Blinks DT 10 20 63
D Board SOS Detect D Board SOS Detect 64 SOS LINE LINE MONITORED NUMBER OF TIMES THE POWER LED BLINKS SOS 2 15V 2 BLINKS SOS 3 P3.3V (15V & STB5V) 3 BLINKS SOS 4 PS 4 BLINKS SOS 5 5V 5 BLINKS SOS 6 SC1 6 BLINKS DRVRST 5V DET 6 BLINKS SOS 7 SC2 7 BLINKS SOS 8 SS 8 BLINKS SOS 9 CONF.
DG Board SOS Detect DG Board SOS Detect 65 SOS LINE LINE MONITORED NUMBER OF TIMES THE POWER LED BLINKS STB 3.3V DET STB 3.3V 10 BLINKS MAIN 3.3V DET MAIN 3.
No video, No OSD Determining whether a No video, No OSD symptom is caused by the video process or the panel drive circuit 1. Unplug the unit from the wall outlet. 2. Disconnect the connector DG5 from the DG board. 3. Plug the unit into the wall outlet and turn on the power. 4. If the unit displays a white screen, It is a video process problem. 5. If the unit does not display a white screen, Proceed to check the panel drive circuits.
Electrical Location of Connector DG5 67
Physical Location of Connector DG5 DG5 68
Physical Location of Connector DG5 (Close-Up View) DG5 69
Isolation of the SC and SS Boards If any of the connectors providing the 15V or VSUS voltage to the SC or SS board is disconnected while the connectors that provide the Scan and Sustain Drive pulses from the D board are still connected, the TV will shut down.
Isolation of the SC and SS Boards Precaution: Do not let the TV run for more than 30 seconds while isolating any of the circuit boards. The Scan Board (SC) and the Sustain (SS) board could be easily isolated. This can be useful to diagnose: 1. Shutdown Problems 2. Video Problems.
Isolation of the SC Board Connector Location The SC board could be isolated from the sources (Supplied Voltage & Scan Control Pulses) Supplied Voltage = VSUS (Connector SC2) 15V (Connector SC23) From Power Supply (P board) Scan Control Pulses = Connector SC20 from the SC board 72
SC2, SC23, and SC20 Disconnected SC board completely isolated from the sources (P and D boards) 73 This is useful when the Power LED Blinks 6 or 7 times.
Expectation when Isolating the SC Board The Supplied voltage VSUS and 15V (SC2 & SC23) cannot be disconnected while the Scan Control pulses (SC20) are being supplied to the SC board. This will cause a shutdown condition.
Isolation of the SC Board The SC board could be isolated from the Driver Boards (SU &SD) Sometimes the TV goes into “Shutdown” indicating that the problem is located on the SC board. This does not necessarily means that the SC board is the cause of the problem. When this occurs, Disconnect both the SU and the SD boards from the SC board. Note: To disconnect, remove 2 screws holding each of these boards in place and disconnect SC41, SU45, SD46 and SC42.
Isolation of the SC Board The SC board could be isolated from the Driver Boards (SU &SD) Sometimes the TV may not go into “Shutdown” when there is a scan problem. This symptom seems to be caused by a defective D or SC board. When in reality, it is caused by the SU board. Disconnecting the SU board yields a good picture at the bottom half of the screen and a completely black area in the upper half of the screen. 76 When this occurs, disconnect the SU board from the SC board.
Isolation of the SU Board Defective SU 77
Display Problem Please no wild guess _ 1. What is the cause of this symptom? 2.
Isolation of the SD Board Please no wild guess _ 1. What is the cause of this symptom? 2.
Supply Voltage from P to SS board SS12 P11 VSUS P12 SS11 VDA 15V STB12V VDA To completely isolate the SS board: 1. Disconnect P12 and P11 on the P board and SS23 on the SS board. 2. Place a jumper at pin 8 and 10 of connector P12. 5V AND SUSTAIN PULSES SS23 SS34 80 The screen is black because there is no VDA voltage from P12 of SS23 provided to the C boards.
Supply Voltage from P to SS board PLACE A JUMPER ACROSS PIN 8 and PIN 10 of CONNECTOR P12 on the P-BOARD If P12 or SS12 is disconnected, pin 8 should be connected to pin 10.
No output to SS board from the D board CN SS23 NO 5V AND SUSTAIN PULSES to SS BOARD NO VDA TO C BOARDS 82 Only SS23 Disconnected CN SS34 STB12V JUMPER
No output to SS board from D board 83 Only SS23 Disconnected
No output to SS board from D board No Sustain Control Pulses and No VSUS 84 Pin 1 from P12 provides the VDA voltage to SS board
Defective D board 85
Defective D board 86
Defective D board 87
SC Board 88
SC Board 89
Defective DG board 90
Forum Thank you for your participation 91
