Toshiba LED TV, blank screen

[tpod77]

Re: Toshiba LED TV, blank screen

Hello all. I've been reading this thread for about a year. I picked up a Toshiba 46L5200U1 from work. My employer purchased it to use as a display for a Rolex ad running on repeat ad nauseum (I'm a jeweler at a high-end jewelry store). It burned out after 18 months. The Toshiba logo appeared in red after powering on and then it went dark with the image visible only when viewed with a flashlight. I found this thread after a quick Google search and tried pulling the #15 DIM wire. I felt a great sense of accomplishment but it went away after five minutes when the screen went dark again. The TV went into the basement and after a year my fiancee said the TV needed to be fixed or it was going to the dump. I bought a new LED driver board, reconnected the #15 wire, and voila, it worked again. For two weeks. I'm at a loss. I've read the entire thread. Should I take another crack at it? The resistor solution sounds promising but I don't have a whole lot of experience with DC circuits.

[googlefu]

Re: Toshiba LED TV, blank screen

So I really hoped this would work for mine. I just got this TV used on CL. I hooked it up as a second monitor to my computer and the first night it worked beautifully. I fell asleep watching Star Wars and life was beautiful. The next morning it was dark, I assumed it had gone to sleep. But it never woke up.

So here's what it does. I plug it in, push power, the light comes on and the screen backlight comes on with nothing but gray until the Red Toshiba logo comes on for a split second and then the screen goes dark but the light is still on. Unplug and try it again. Same. and again. and again.

Then I came here and read the comments and tried pulling plug 15. No dice. So it pulled the yellow wire on the other side too. Same thing.

I tried moving the wire bundle from P804 to P803. No change. I also pulled out wire 14 marked Ex_dim and then tried it again on the other side of the bundle. No change. I always get a flash of the toshiba logo and then nothing. Any ideas?

[the8re]

Re: Toshiba LED TV, blank screen

Howdy all. Found this forum as I had a 46L5200U1 with this very same issue. Opened it up, pulled wire 15, put it back together, and I'm good as gold. Thank you all so much!

Even updated the firmware while I was at it.

Additional info: The TV came with the house when we bought it. The sticker on the back says September 2012.

Again... thank you all for keeping the peace in my house!

-t

[simondumais1]

Re: Toshiba LED TV, blank screen

Could these LED fit these strips?

Cree XLamp ML-C

I have a 46L5200 that is flashing the toshiba logo. I have to test for the led arrays, but i would like to fix it properly by replacing a LED if it is a LED that is broken. I've watched the videos that Norcal715 did on this exact same problem but he did install a Zener in place of the LED.

What you guys think?

[D-Einsight]

Re: Toshiba LED TV, blank screen

I'm like everyone else .... Toshiba 46L5200U1 1-1/2 yrs old , black screen .This is some WONDERFUL information Guys !!!!! I'm going to give it a try tonight !!!! D-E

[vesterlee2008]

Re: Toshiba LED TV, blank screen

I own a TOSHIBA 46L5200U1, I replaced the power board and now the red Toshiba comes on. There was still no picture when I hooked up my bluray player. I actually read through some previous threads and removed the yellow wire. BOOM just like that it is now working. There is a slight dis-coloration on the left side but hardly noticeable. I would still like to know what else could be a fix because I am sure the yellow wire needs to be connected.....

[vinceroger69]

Re: Toshiba LED TV, blank screen

It maybe better if you start a new thread for your tv please include the model number and some good clear pictures of the boards used in your set.

[vesterlee2008]

Re: Toshiba LED TV, blank screen

I have the same issue, I have no back light or any kind of lights coming on my tv. I cant even see the Toshiba logo unless I shine a flash light on it. I have sound but no picture unless I shine a flash light on it. Any help is needed. I have read every thread and not one them helped with my issue.

[budm]

Re: Toshiba LED TV, blank screen

Did this and it seemed to work, but for how long. Other post say this may bring other issues, like heating and such. There is a work around by placing a resistor from "pin 13" to ground. My question is what "pin 13", there are a couple on the board. A Pic of the work around would help.

LED driver board pin 13. look at the pictures in post 88, and read the rest of the threads.

[Sierra9093]

Re: Toshiba LED TV, blank screen

Hi, pulled wire on pin 15, and it worked. I would like to put the resistor workaround for the heat problem. I wish you would post a picture or a diagram of the resistor fix. Thanks in advance.

[Sierra9093]

Re: Toshiba LED TV, blank screen

The above info was nearly correct. Pull the #15 wire and tape it off. (You can read the board code that says "dim".) Viola! I just figured this out today, and multiple tests show success.

Did this and it seemed to work, but for how long. Other post say this may bring other issues, like heating and such. There is a work around by placing a resistor from "pin 13" to ground. My question is what "pin 13", there are a couple on the board. A Pic of the work around would help.

[budm]

Re: Toshiba LED TV, blank screen

tibimakai, if you could find the time, could you post a picture of your repair regarding the resistors. I have unplugged the #15 wire and now my set is working. But i would like to add the resistors if that will help the fix stay fixed longer.

Read post 88 on up to see what we have done.

[tibimakai]

Re: Toshiba LED TV, blank screen

That TV is sold already.
All the info that I have, is in the thread.

[Sierra9093]

Re: Toshiba LED TV, blank screen

tibimakai, if you could find the time, could you post a picture of your repair regarding the resistors. I have unplugged the #15 wire and now my set is working. But i would like to add the resistors if that will help the fix stay fixed longer.

[budm]

Re: Toshiba LED TV, blank screen

BTW, the LEDs in that Video are Dual-LED (two LEDs connected in series inside one package) that is why the Vf is so high.

[Agent24]

Re: Toshiba LED TV, blank screen

That's what hot air rework tools are for.

You may also be able to do it with a heat gun on low from the bottom side of the board.

[Treydogg77]

Re: Toshiba LED TV, blank screen, LED Replacement

Okay I finally took the TV apart to see how many LED were out and it was one! What's the easiest way to remove one of these LEDs? I have a light strip from another TV that I can use to replace the LED. I am having trouble removing the led without damaging it. Check the pictures

[Treydogg77]

Re: Toshiba LED TV, blank screen Question For "Bud"!

Bud,

Where can a man find LEDs for this unit other than Fleabay? If anyone else has a line on these led or led strips feel free to chime in!

Thank you,

T-Dub

[tibimakai]

Re: Toshiba LED TV, blank screen

You should take the screen apart and see, which one causes the problem.

[tom66]

Re: Toshiba LED TV, blank screen

I have noticed this failure mode with LEDs before. I have had several 230V "GU-10" LEDs fail, these are small ones you get in kitchens etc. Normally 35-50W halogen but replaced with LED to save energy.

Usually they begin to flicker and pulsate before they go out for good. Always just one LED that dies in a chain of about 50 or so. Seems it might be a failure of the bond wires as it's some kind of thermostatic effect.