Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

[Locutor13]

Hi,

I am learning how to fix TVs, I buy broken TVs and I try to repair them. I have been using this and others forums as a reference and so far, I have been lucky but now I need some advice.

I got this Panasonic TH-C50FD18 (the COSTCO model # of the TH-50PZ85U) with a problem with the screen, 1/3 of the screen was showing perfect picture and 2/3 of the screen was complete white “NO DATA”.

The 1/3 of the screen that was showing perfect picture is where the C1 data-buffer is and sometimes for a blink of an eye, I was getting full screen picture (for 1 second or less). My first diagnose was 1st a faulty C2 & C3 data buffer, 2nd a faulty D board and 3rd a faulty COF.

My first intend for repair was to replace the C2 and C3 data buffers but it didn't fix the problem.

After replacing the C2 and C3 data boards, I was troubleshooting the TV with the DMM monitoring the VSUS voltage (190V), when I noticed when I was using the HDMI 3 located in front and below the TV's screen (underneath the Panasonic logo), that I was having the same 1/3 of the screen with perfect picture and in the 2/3 of the screen with “NO DATA” instead of having the 2/3 of the screen complete white I was getting some pink red and shadows that were somehow following the patterns of the pictures and the VSUS went down from 190V to 177V when using the HDMI3 with connected to an apple TV.

While I was doing this the TV suddenly turned-off and I got a 4 blinks code and thereafter each time that I try to turn it on I am getting the 2 blink error code (15V SOS D-Board). After this happened I touch the screen and it was very hot.

2 BLINKS TROUBLESHOOTING[/B]

When I plug the TV, I get 2 Clicks and a 3rd one after a few seconds indicating that everything is ok; therefore the TV goes into stand-by with no problems and the STB 5V is there. When I push the power button I can see the fans working for a bit until the TV goes off and I get the 2 Blinks code.
Before the TV turns off I get the 15V voltages but no VSUS.

The following link shows exactly the symptoms that my TV is experiencing:

https://www.youtube.com/watch?v=uwaZs6nqzps

So far I have done the following trouble shootings to test the power board:

- I have performed the Norcal's freezing test with the IC201 & IC301 and it didn't pass. This is not the problem.

https://www.youtube.com/watch?v=LjpGKaBt8hg

- I have disconnected the X and Y boards and used the jumper SS34 at P12 of the PSU and the VSUS didn't show-up. There is no a 2 Blinks VSUS misdiagnose due to a shorted X or Y boards. I have found that this may happen.

- It is not a problem with the thermal fuse of the VSUS's transformer, I have check continuity between R251 & R252. Check page 45 of SM on the cold side of transformer T201.

Before I move on I would appreciate your help with the following:

- Is there a way I can bypass the D-Board and prevent the power board to turn-off? Knowing all the different issues with the power board of this model and would like to be sure that is not faulty.

- Have someone ever experienced a 2 blinks code, that was indeed a faulty D-BOARD?

- What are the chances that what I have is a faulty panel?
I am attaching some pictures and a lay-out of the panels.

Thank you in advance for your help and advice,

[tw2005]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

If it's directly related to a PZ85 then they have a PSU issue 2 and 10 blink. has to do with the MC201 and MC301 modules and usually a tiny 1uf cap on that goes bad. I had one and it was 2 blink, easy fix with a new cap, 15V line module I forget which is which but there are posts here about it and a youtube video that shows the repai, by norcal715

Not sure about the 4 blink or screen being hot?

[tom66]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

If the data buffers are driving the panel wrong you're losing ABL capability which can overload the Vsus.

A 50" FHD panel at full white will use a huge amount of power, so the ctrl board will dial this in a little to reduce power usage (automatic brightness limiter), but if this ain't working you're going to get odd effects from overloaded/sagging Vsus. It is possible this could eventually kill the PSU's Vsus tract too.

Note running a panel at huge power levels can crack it so do be careful. Panels have a maximum continuous sustain power, for these it's about 450W. ABL dials in above about 70% screen bright, so you might have been pumping ~640W into the panel. not good.

[tw2005]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

If it's directly related to a PZ85 then they have a PSU issue 2 and 10 blink. has to do with the MC201 and MC301 modules and usually a tiny 1uf cap on that goes bad. I had one and it was 2 blink, easy fix with a new cap, 15V line module I forget which is which but there are posts here about it and a youtube video that shows the repai, by norcal715

Not sure about the 4 blink or screen being hot?

sorry, ignore. did not read the post thoroughly

[Locutor13]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

Thank you for your answer tom66,

Most of this stuff is new for me so I might take a while to answer as I have to process & understand all the info.

What I think I understand by your answer is that if the brightness of the TV have been setup or gone so high that it will overlap or make the picture of the whole screen gone white drove by the data buffers. Since I have replaced the C2 & C3 data buffers I don't think they are driving the panel wrong but I might be wrong.

I will try to explain what I was experiencing with the picture using the attached diagram, as a reference:

What was happening is like if the video data flowing from the IC9400 to the C2 & C3 data buffer was somehow interrupted and therefore I was having a complete white screen “NO DATA” in the area of the screen covered by these two data buffer and full normal picture in the area of the screen covered by the C1 data buffer (From CB1 to CB5 included CB6).
Note: CB6 data comes from the IC9400 by the C2 data buffer through the C20, C21 & C10 connectors.

I hope this will to give a better idea of what was happening with the TV before the 2 blinks,

Thanks again,

[Locutor13]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

This is an update on my post. The reason why I was getting the 2 blinks code was because the two mosfets of the 16N55G on the primary part of the transformer T201 were blown. I have replaced them and the power supply board is back fully functional and providing all the right voltages. I have attached a picture of how my power supply looks like with the new mosfets placed on one side since I broke the metal plate were the originals were glued too.
Also I have attached a picture of the TV turn-on, the part that is showing a light blue color is where I have picture; the white part comes only for a few seconds but most of the time stays white. It is showing in light blue color because I have disconnected the A5 connector from the A board, therefore the image is provided directly by the D board.
What is happening is that for some reason the C2 and C3 buffer boards are being shutdown stopping the data going into the panel. At this point I would like to find some way to do further tests in order to determine if the panel is bad.
Any help will be highly appreciated.

[Locutor13]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

Hi, this is only an update of my previous post. The problem with my TV still persists but I have some additional information that someone might find useful:

1.The reason why I took the picture of my previous post with the connector A5/D5 disconnected is because I was using a defective A board that I took from a Panasonic model TH-42PZ80U on the TH-C50FD18. The problem with this A board was the well know after power surge or electric storm problem; where the TV will turn-on with a steady red led light without picture or sound and the screen will turn on with a dim light. Other symptoms are: the TV won't answer the remote control, to turn it off it has to be unplugged and the TV will experience power cycles most likely for the absence of signal. When I put the A board of the TH-C50FD18 in the TH-42PZ80U, the TH-42PZ80U returned to full functionality and when I put the faulty A board in the TH-C50FD18 it experienced the same faulty symptoms already described. Therefore the A boards for these two models are proven to be fully interchangeable.

2.I have attached two recently new pictures, the first on shows the whole screen with normal picture and the second will show only picture in 1/3 of the screen with normal picture and 2/3 of the screen white which it is how it looks the 99% of the time. These pictures were taken the connector A5/D5 connected to the faulty A board that I was able to bring back to life.

As follows you can find an explanation on how to partially repair a Panasonic A board TNPA0721:

The symptoms:
The problem with this A board was the well know after power surge or electric storm problem; where the TV will turn-on with a steady red led light without picture or sound and the screen will turn on with a dim light. Other symptoms are: the TV won't answer the remote control, to turn it off it has to be unplugged and the TV will experience power cycles most likely for the absence of signal.

The reason:
A shorted IC4510 ADV749B ANALOG DEVICES, it can be tested with by measuring the resistance between the pins that are connected to the hdmi port, directly in the chip and ground. Any lectures below the Mega ohms means shorted. Also if you measures continuity through the capacitors C4599 and C4601 they will appear to be shorted.

Partial solution:
Bypass the IC4510, simply remove the tiny inductor L4512. One of the main sources 3.3V coming from the IC4511 (Ref# page 58 of the SM) to the IC4510 will be interrupted and the 2 HDMI ports will be bypassed. You should be able to still use the others inputs, for ex. For the attaches pictures I have the TV hooked to an antenna. NOTE: There might be a better way to do this.

Possibly complete solution: I haven't tried it but by replacing the IC4510 (you can buy it in EBay for $5) and putting back the tiny inductor L4512 the problem might get resolved. There is good 3 part video in YouTube that shows how to replace and trouble shoot the HDMI/chip: Panasonic Viera Main Board Repair by RetroGameModz, even though is not the same problem it will point you in the right direction and possibly come with a better to tackle the problem.

Going back to my original problem, I suspect that the problem comes from the D-Board but I am still looking for a solution or to get another board that I can test in my TV.

[Locutor13]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

Hi, Changed the D-Board and solved the problem the 2/3 of the screen going white, I have attached a picture of how the TV looks like with full screen.

P.D: I haven't yet tried to replace the IC-4510: IC4510 ADV749B ANALOG DEVICES in order to have the 2 HDMI ports of the A board working back again. Please let me know if someone has already tried it.

[Locutor13]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

Picture.

[paulmich]

Re: Panasonic Viera Plasma TH-C50FD18 2 Blinks error code and picture problem

hi, I have the same problem with the A-Board for a PANASONIC TH-50PX80U. Power on but no image. The only repair service I know tell me to replace the A-BOARD, but I prefer buy a new one instead of put 200$ on this TV, but I can only repair instead of replacing, I think it's a good thing to try... I saw you're from Quebec, do you speak french? my english is so bad...

Do you know what can I do with this problem? Do you know where I can find someone to repair it? Because I don't think I'm able myself...

Thanks