Saturday, February 13, 2016

How to enter service mode Panasonic Plasma TV - PANASONIC FHD PLASMA TV - TC-PXXST30 - Vsus – Vda – P15V troubleshooting - Fault finding – Plasma television repair and service

Category: Plasma Television Repair and Service 

Contents of this article 

  • Vsus troubleshooting
  • Vda troubleshooting
  • P15V troubleshooting  

PANASONIC FHD PLASMA TV

Quick Procedure To Check For Short or Low Resistance Condition of the Vsus, Vda, and P15V Lines
Note: Vsus is generated by the Power supply and is only used by the SS and SC boards
Vda is generated by the Power supply and is only used by the Panel (Panel Drive ICs)
P15V is generated by the Power supply and is used by the A, SS, and SC boards.
Test points for the Vsus, Vda, and P15V can be easily found on the P board. To check for short circuit or low resistance on these lines, follow this procedure:
Preparation
1. Make sure the TV is disconnected.
2. Remove any residual charge from the Vsus and Vda lines by momentarily grounding them through a 500 ohms resistor (At least 5Watts).
3. Measure the resistance between chassis ground and the pins indicated on the table below. A dead short or a reading lower than 1K indicates a shorted or partially shorted line.
Voltage Test Points
Connector/ Wire Color
Pin Number
Voltage
P11/White
1
Vsus
P11/Brown
4
P15V
P35/White
1
Vda

Quick Procedure To Determine the Cause of the Problem if a short or Low Resistance Reading is Found
Shorted Vsus
Note: Vsus is generated by the Power supply and is only used by the SS and SC boards
If a short is found on the Vsus line, remove connectors P2/SC2 and P11/SS11 one at a time to determine if the SC board or the SS board is defective.
Shorted Vda
Vda is generated by the Power supply and is only used by the Panel (Panel Drive ICs)
If a short is found on the Vda line, is likely that the panel or one of the C boards is defective. To determine which is defective, remove connector C10 between the C1 and C2 boards and the panel’s flex-cables connected to the C boards one at a time.
Shorted P15V
P15V is generated by the Power supply and is used by the A, SS, and SC boards.
If a short is found on the P15V line, remove connectors P6, P11, and SC20 one at a time to determine which board is defective. A shorted P15 is primarily caused by the following boards in the order presented; SC, P, A, and SS boards.
Note: Even though is not common, the P board can also cause a shorted Vsus, Vda, or P15V.

Connectors location
Detailed Troubleshooting Procedure for Shorted Vsus
Unplug connectors P2 and P11, on the P board. Measure the resistance between pin 1 of connector P2 and ground (Chassis)
Is there a short circuit?
If yes  Replace the P board
If no then Measure the resistance between pin1 of connector SC2 on the SC board and ground (Chassis).
Is there a short circuit?
If not then Replace the SS board
If yes then Measure the resistance between pin1 of connector SS11 on the SS board and ground (Chassis).
Is there a short circuit?
If yes then Replace the SC and SS boards
If no then Replace the SC board.
Detailed Troubleshooting Procedure for Shorted P15
Unplug connectors P6 and P11, on the P board. Measure the resistance between pin 1 of connector P6 and ground (Chassis)
Is there a short circuit?
If yes then Replace the P board
If not then Reconnect P11 and measure the resistance between pin 13 of connector P6 and ground (Chassis)
Is there a short circuit?
If yes then Replace the SS board
If not then Disconnect SC20 on the SC board and reconnect P6. Measure the resistance between pin 13 of connector P6 and ground (Chassis)
Is there a short circuit?
If yes Replace the A board
If not then Replace the SC board
Detailed Troubleshooting Procedure for Shorted Vda
Unplug the connector P35 on the P board and check the resistance between pin 1 of connector P35 on the P board and ground (Chassis)
Is there a short circuit ?
If yes then Replace the P board
If not then
42” & 46” models Reconnect P35 and unplug the ibbon cable between the C1 and C2 boards. Measure the resistance between pin 1 of connector P35 on the P board and ground (Chassis)
Is there a short circuit ?
If yes then The problem could be the C2 board or the panel. Proceed to isolate the panel from the C2 board to determine which is bad.
If not then The problem could be the C1 board or the panel. Proceed to isolate the panel from the C1 board to determine which is bad.
50” - 55” -60”  -65” models Reconnect P35 and unplug the ribbon cable between the C2 and C3 boards. Measure the resistance between pin 1 of connector P35 on the P board and ground (Chassis)
Is there a short circuit?
If yes then The problem could be the C3 board or the panel. Proceed to isolate the panel from the C3 board to determine which is bad.
If not then Reconnect the ribbon cable between the C2 and C3 boards and unplug the ribbon cable between the C1 and C2 boards. Measure the resistance between pin 1 of connector P35 on the P board and ground (Chassis)
Is there a short circuit?
If yes then The problem could be the C2 board or the panel. Proceed to isolate the panel from the C2 board to determine which is bad.
If not then The problem could be the C1 board or the panel. Proceed to isolate the panel from the C1 board to determine which is bad.