Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

[Tof]

Hello everyone, here is the issue I am facing with my Panasonic Oled TX-65FZ800e.

When the TV has not be used for some hours, I power up the TV with a video input and the image is displayed perfectly for 30seconds and then the TV switch off with the red light blinking every 4 seconds for ever.
The service manual explanation: EVDD_SOS (EVDD 24V error) with check point (oled panel, P board, A board, T-CON)

I opened it and found a burned connector on PB-board on the 24V pins.
The 24V wires have change a bit of color due to the overheat and the corresponding connector on T-CON board has nearly no damage.

On T-CON board, I removed the metal plate and detected a bump surely due to overheat on L6006 wich is located on the 12V rail.
I checked all decoupling capacitors looking for a short circuit but found none.
A short circuit exist on the mosfet source Q6004 (SVDD_CS ?), seems strange to me.
I am waiting for a new part but I do not have the T-CON schematics to check the mosfet wiring.

My first feeling is:
- the panel is OK because each time the video input is displayed, the picture is perfect without artifact.
- an overload seems to exist on the 24V line
- an overload seems to exist on the 12V line

I made some other tests to find this or these overload.

I power up the TV without any video source and then the OSD display a small blue box with "HDMI1".
In the case the 24v (EVDD) and 12V(SVDD) are ok, stable, no overload, no overheat on 24V wires.

Then I plug a video input on HDMI1, the video is displayed perfectly, 24v(EVDD) and 12V(SVDD) are OK but the 24V wires between PB-board and T-CON board becomes more and more hot and the TV switch off (no more 24V either 12V).
If I turn on the TV again, the TV immediately switch off, no 24V either 12V.
I use a freeze spray to check if it is due to a componant temperature but no change, the TV switch off immadiately.
To test again with an image, I have to wait for hours.
I try to detect some overheat with a thermal camera but I found nothing obvious for now.

I still think the T-CON board is guilty and I would like to found the origin of the issue. But now I need some expertise to help me go further and confirm or not my feelings.

I wonder:
1- am I right to think the panel is OK.
2- which component can cause an overload on 24V and 12V.
3- on the 12V line, why the mosfet source Q6004 (SVDD_CS ?) is connected to ground.


Thank you all in advance for any help.

[dskall]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

You repaired and checked your bad connector? Surprised you can't find anything overheating.

[Tof]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

I did not repair the connector for now, I checked it and it was OK even if the plastic is in bad shape. I will do it after fixing the T-CON board.
About the overheating, I was surprised to but nothing obvious between a test with only the OSD and the full picture. However I am not very confident with thermal camera so I will do some new tests.
What about the Q6004 mosfet, is the mosfet here to switch on/off the 12V ?
I am interesting by any block diagram or schematics if that exists.

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

disconect the EVDD 24V, from PCB side... feed the TV with HDMI signal and turn on you will hear the audio and screen should remain black. if this happend and the set didnt turn off for more than 30 minute give here feed back.

[lotas]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

You first of all need to eliminate these contacts on the connector, when a large T-CON current is consumed with a bad contact, the T-CON power connection is lost and an error is triggered, you need to cut these burnt wires, strip and solder them on the other side of the power supply.

[Tof]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

Thanks Diah for the help.
I could disconnect the full black connector on the T-CON board, no signal will miss for the test ?

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

You first of all need to eliminate these contacts on the connector, when a large T-CON current is consumed with a bad contact, the T-CON power connection is lost and an error is triggered, you need to cut these burnt wires, strip and solder them on the other side of the power supply.

you right.. they are 8 wire the 4 burned i think they are all + and the other 4 chassis but still the middle one close to the chassis one.

[Tof]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

I disconnected the black connector to remove the 24V and inject an audio/video source on HDMI1.
The result is no picture, no sound.
I checked the 12v (SVDD) and this one is switched off immediately.

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

Thanks Diah for the help.
I could disconnect the full black connector on the T-CON board, no signal will miss for the test ?

friend.... need from PCB because later i will tell you how to repair this socket if our first test run successful

[lotas]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

There are 16 pins plug.

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

I disconnected the black connector to remove the 24V and inject an audio/video source on HDMI1.
The result is no picture, no sound.
I checked the 12v (SVDD) and this one is switched off immediately.

turn on with remote maybe it went to STBY ... and we said from PCB pluf it out.... if now you have short on this damaged socket... the matter will be bigger

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

There are 16 pins plug.

later when he take the the i´´EVDD PCB inverter boards we will see each 2pin up & down are soldered together.

[Tof]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

I am afraid I did not understand your remark Diah.
When you say disconnect from PCB, you mean from PB-board, the board with the burned white connector ?

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

I am afraid I did not understand your remark Diah.
When you say disconnect from PCB, you mean from PB-board, the board with the burned white connector ?

yes of course this boards are EVDD inverter boards.. i would suggest you better things.. first take the boards out and let look under side whats going on there before we do further things. always please yours photo let it focused with high resolution. so we can read any label or the soldering diagram chart

[Tof]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

Here the pictures of PB-board. I add one picture showing the PCB wich has burned a little bit between 24V pins on PB5 connector and D7553. I check the D7553 diodes which have the same behavior than the others.

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

okay thanks... but can you please upload focused photo closed only on the burned socket from down side we cant see the green circuit chart layout ,,, and on the top right you have one socket with one cable ist EVDD ON ?

[Tof]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

Here are the pictures with a closer focus on burned socket down side and EVDD_ON socket.

[Diah]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

okay thanks evdd on now confirmed.. still the socket down photo not clear to my poor eyes,,,LOL .. test with your DMM peep ton mode between the raw up 1 to 2 down , up3 to down 4 up 5 to down 6 until the end up 15 down 16 to see which are share same line

then the up raw 1 -15 between them which are read one line and the down raw from 2 to 16 which are read one line.

[lotas]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

24v schematic

[Tof]

Re: Panasonic Oled TX-65FZ800E, no picture, red led blinking every 4 sec

I have got the service manual of this tv with all schematics except T-CON board if it can help.