Question Thomson Android TV, blank screen after boot

[krisztianpolyak]

Hello guys,

I'm looking for some advice.
In the morning I turned my TV (Thomson 65UC6406) on as usually, and it greeted me with a blank screen.
Actually

• the Thomson logo shows up
• the Android logo shows up
• it goes blank but the playback starts (I can hear the sound)

I'm not sure if it is firmware, main board or d-con issue.
I've tried to install different firmware, but did not really help. So it is probably a hardware issue.

Would the logos show up if the d-con were faulty? Maybe it dies when the system tries to switch to 4K?

On the Internet, some mentioned that it might be a problem with the instant power on feature. Is there any way I can disable it without accessing the menu?

Any advice?

Thanks in advance

 

[neocrack]

Hi, sir!

Problem solved? I have the same issue and don't know what to do.

Thanks in advance!

 

[krisztianpolyak]

Hi, sir!

Problem solved? I have the same issue and don't know what to do.

Thanks in advance!

Well, unfortunately not yet solved, but I'm on it.
Because I am simply not able to get a technician to have a look at it (WTF???), and actually I have already prepared myself to buy a new TV anyway, I decided to try to examine this issue myself.

First I've checked with a flashlight if there is picture on the screen. There is, so it is probably not a main board or t-con issue.

I have some basic knowledge of electronics, so I've opened it up to check the voltages on the power supply. And even the power supply seems to be ok. I've measured normal voltages everywhere.

Then I've tested the led strips with a tester and realized that one of the strips were dead. (I guess the power supply shuts down the back light, when the strips consume more/less power than they should)

I decided to replace the faulty LED strip, but because I was not able to find any information on the internet, I could not figure out the model number. So I had to open the TV even more, removed the LCD panel, the stupid light diffuser layers, to finally get to the LED strips. I removed the faulty strip, and tested the individual LEDs. Only one of them were dead, so first I thought I'll just replace it, but unfortunately I do not have the right equipment, so I quickly failed 😀 But at least now I know the model number and I was able to order a new set of LED strips. It is in transit for two weeks now, and I have no clue when it will arrive.

Until then, fingers crossed 😀

 

[neocrack]

Thank you very much for the information, I'm not alone in this Luckily, I have the equipment under warranty and I hope they can repair it soon, I will let you know. Some quick questions:

• Have you tried updating the software via USB to see if the problem is solved?
• Did the problem arise from nothing without failures in the previous days?
• Last night it happened to me that the television did not directly turn on. That is, neither with the remote control nor with the lower button did it start. Has the same thing happened to you?

Thanks, thanks, thanks.

 

[krisztianpolyak]

I have tried to install few different versions of the software via USB. Interestingly the back light was on during the update process, but otherwise it did not solve the problem. After restart, the screen went dark again. Actually I've reached the point when the back light did not come up anymore at all... maybe just flashed once for a split second. That was the point where I got suspicious about the LEDs instead of the software 😀

I cannot recall any prior failures. I was watching TV at night, the next morning the screen was blank. Everything was fine before that.

 

[neocrack]

Your situation is the same as mine, it stopped working overnight. I will try to update the software in case the miracle occurs.

Thanks again!

 

[krisztianpolyak]

Your situation is the same as mine, it stopped working overnight. I will try to update the software in case the miracle occurs.

Thanks again!

Good luck

 

[krisztianpolyak]

Well, my case is solved.
The LED strips have arrived, I replaced the faulty one, and everything seems to be fine.
I've almost thrown my TV away because of one faulty LED, and the lack of support and service.
Kinda proud of myself 😀

 

[neocrack]

Congrats, Sir! Got to be proud of yourself.

For my part I am waiting for the technician to come to my house to fix it. A couple of questions:

• What LED Strips model did you buy and where? In case I finally need to fix it by myself.
• Is the process the change it easy? Could you describe it briefly?

Thank you very much for the update.

 

[krisztianpolyak]

Congrats, Sir! Got to be proud of yourself.

For my part I am waiting for the technician to come to my house to fix it. A couple of questions:

• What LED Strips model did you buy and where? In case I finally need to fix it by myself.
• Is the process the change it easy? Could you describe it briefly?

Thank you very much for the update.

Well, when I first opened it up and dug down to the LEDs, simply because I've never done it before, it was a real pain in the a**, and it took me half day.
Yesterday, when the new LED strips arrived, it took me maybe twenty minutes to disassemble the TV, replace the faulty strip and put it back together.

I've done it all because

• I simply could not find a technician to fix it
• I was always interested in DIY and electronics, so in a way I really enjoyed doing it
• I had some free time to waste
• I was prepared to buy a new TV if I failed, so it was just kind of an experiment 😀

So if you want or have to do it, I would suggest the following:

Figure out if it is just a LED problem before you buy new LED strips and disassemble your TV.

• Turn your TV on, wait a little until it starts up (unfortunately you can't see it, so just wait a couple of minutes)
• Aim a flashlight to the screen from few centimeters
  • If you can see the image on your screen where the light hits it, then chances are that it just a dead LED. (Still can be something else though)
    • So let's remove the back cover and test the led strips. You can buy led testers dirt cheap, or you can ask someone to lend you one.
      • If any of the strips won't light up or the voltage is suspiciously high or low, then you found the problem (or at least one of them) and it needs to be replaced.
      • If all of them seem to be working, then it is a different story and needs further investigation
  • If there is no picture on the screen, then it is a different story, and it needs further investigation

If it's not the LEDs, you can still buy any of the boards very cheap (well, much cheaper than a new TV), so even if you replace everything inside, it won't cost too much.


If after these steps you think you should replace a LED strip, here comes the funny part.
Learn from my mistake, and don't order just any LED strip you find I was hoping that TCL/Thomson uses the same strips in the same size models, and just ordered the first one I've found. But I could not have been more wrong. Now I have a set of LED strips I cannot use for anything 😀

In my case (Thomson 65UC6404) the LED strips are identified by
The board number: TOT_65_D2900_12X7_3030C_D6+-2D1_7S1P
Or The TCL part number: TCL 006-P1K3507B

If you do not have the exact same model, I can't guarantee that you need the same strips.

Unfortunately when I tried to figure out the board number, I was not able to find any information on the Internet, so the only way to find out, was fully disassembling my TV.

Once you know the board number, it is relatively easy to find used or new led strips for sale, and it arrives relatively fast even from the other end of the world 😀

So when you've got your new strips, let's do the dirty job:

What you will need:

• enough place for the TV, In my case it was my King size bed 😀 First I wanted to do it on the floor, but it is not really comfortable to kneel and crawl on the floor for hours 😀
• phillips screwdrivers, different sizes for the legs, for the back cover, for the rim
• storage for the screws (you will have to deal with around 40-50 screws, it's a good idea to store them somewhere)
• I have done it alone, but it is a big TV, so it good to have a helping hand

Steps:

1. lay the TV down (screen downwards)
2. remove the legs (if you use them)
3. unscrew th back cover
4. remove the back cover. Carefully, because it is connected to the main board. Just lift the cover and disconnect the cable.
5. remove the rim screws. There are around 20-25 small screws around the edge of the screen.
6. turn the TV around (screen upwards). Carefully, nothing really holds the rim anymore. To protect the boards, if you want, you can put the back cover back to its place, but don't screw it back.
7. remove the rim. You just have to pop it up in few places. Be gentle, don't break it Remove it and put it aside
8. lift up the LCD panel
   1. the LCD panel is connected to the d-con board at the bottom by very fragile cables. You can disconnect these cables if you want, or you just keep in mind that they are there
   2. lift the top of the LCD panel, to a perfect angle (while its bottom stays where it is). You can ask someone to hold it or (like me) you can lean it to the wall (or the head of the bed)
9. remove the light diffusor holders on the two sides. Two plastic rails. They will just pop up like the rim.
10. lift up the light diffusors
    1. there are two thin layers, lift them up and temporarily attach them to the LCD panel with some tape, or ask somebody to hold it.
    2. there is one thick, rigid layer, you can just remove it and put it aside.
11. now you can finally see the LEDs, but there is still one more white paper layer, you need to lift it up to access the led strips.
    1. there are plastic spacers, you have to unscrew them
    2. and the paper layer itself is glued down, you don't want to tear it into pieces, so carefully lift it up at every glue point
12. unscrew the faulty LED strip
13. disconnect the connector at the end of the strip
14. connect and screw the new strip into its place
15. Go from point 11 backwards, and put everything back together 😀

- put back the paper layer
- screw back the spacers
- put back the thick, rigid layer
- put back the two thin layers
- put back the diffusor holders on the two sides
- put back the LCD panel
- put back the rim
- turn the TV around (screen down) - if you used the back cover, remove it
- screw back the rim
- connect the back cover's cable to the main board
- put the back cover to it's place and screw it down
- screw the legs back (if you use them)

Done....hopefully you have a working TV. It's worth checking it before you screw everything back together

First it was a nightmare, but yesterday it took me much less time than writing it down

 

[neocrack]

Wow! Thank you very much for the explanation, it's absolutely awesome and couldn't be better detailed. I am sure that it will be useful to anyone who faces this problem, since the information I've had found so far was scarce since I joined this forum.

This week the technical service will give me an answer about my problem, so I will update the thread in case someone might be interested.

Thanks again for your selfless collaboration. I am convinced that you would be faster and more efficient than the technical service and would be happy to offer you a couple of beers, but I'm afraid we should be thousands miles away (I assume you are American and I write from Spain).

In any case, thanks again, you really rock.