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.
2. The LED in the Optical Jack inside the DT board turns on for approx. 4 seconds.
1. There is a click from the relays RL402 and RL403 when they are activated.
3. Immediately after that, one of the Tuner LEDs (Right) turns on (Solid Red) for approximately 20 seconds.
4. The LED in the Optical Jack inside the DT board turns on again for approx 1 second and both LEDs (tuner and optical jack) turn off.
5. Then you will hear another click from the relays RL402 and RL403 indicating that they are no-longer engaged. (Note: At this time the Tuner and the Optical Jack LED turn off.)
No Power Troubleshooting Chart
To rule out the P board (Use a Peak Hold Meter for voltage reading)
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).
> Because you only have 2 to 3 seconds to measure the STB 14V, place your meter’s probe at pin 1 of connector P10 on the P board before plugging the TV to the AC line.
> Plug the TV to the AC line while still holding the probe at pin 1.
> Check to see if the 14V comes up. If it doesn’t come up, the P board is defective. If it does, (since it may take some involvement to determine which of the PA or the DG board is defective) it’s OK to order Both the DG and PA boards together.
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
DG
Board SOS Detect
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.
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.
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.
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.
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.
1. Shutdown Problems
2. Video Problems.
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.
If only SC2 is disconnected while SC23 and SC20 are connected:
The Power LED blinks 6 Times.
If only SC23 is disconnected while SC2 and SC20 are connected:
The Power LED blinks 7 Times.
If both SC2 and SC23 are disconnected while SC20 is still connected:
The Power LED blinks 7 Times.
If SC20 is disconnected while SC2 and SC23 are still connected:
The Power turns ON (Black Picture – No OSD – Sound is OK, and there should be video out of the Monitor Jack)) SS LED is ON and SC LED is OFF.
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.
Note: To disconnect, remove 2 screws holding each of these boards in place and disconnect SC41, SU45, SD46 and SC42.
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.
When this occurs, disconnect the SU board from the SC board.
Note: To disconnect, remove 2 screws holding the boards in place and disconnect SC41, SU45.
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.
Defective SU
