Toshiba 40L1333 Led Backlight Mod

[ReeceyBurger123]

Hello everyone, a prime common fault with these tvs (toshiba 40l1333) is the led back lights failing. I have 3 of these tvs in all with faulty led bulbs, as buying exact replacements is too expensive and replacing the old faulty diodes is impossible to do due to the plastic layer that covers the solder pads on the original led strips. As I knew that the psu runs the 24v as soon as the tv is turned on I had the great idea of replacing the high voltage stock leds and there respective driver board with strips of pure white bright 24v leds that I got off ebay in 5m rolls for £6 each. I fully removed all the old leds and mounted the new ones wiring them in a electrode type set up and covered the wires and electrodes with captain tape to make sure the connectors are isolated and arnt going to short, I mounted the leds to the back of the chassis for cooling purposes. Now I had to mod the psu and add 2 more 20a 100v shot-key t022 diodes as the single output diode package for the 24v rail was getting very hot as it wasn't powerful enough to power the 10 1m strips of leds in the screen, after adding two more diode packages off a scrap 17pw16 the psu now actually runs cooler and the leds are fully lit up and are extremely bright. Over all they run cool and look like the factory diodes when it comes to the brightness. The problem is now that I cant fit the original light reflector and the light is poorly focused on the screen and looks horrible, the lcd does light up and color is displayed but you can see where the strips of diodes are and it looks horrible. So what can I do to solve this I have ordered aluminum tape to stick to the panel to act as a light reflector but will that work ? Will I need to build or find some sort of more intense light diffuser for the top ? Will this work ? Are the Leds too bright and dont have optics to spread the light ?
Please if you have any ideas on this any help will be much appreciated I have made a youtube video here is a link to it, please take the time to watch it as it explains everything about this mod. Thank you in advance.

Link to the video with full explanation of the mod:
http://youtu.be/813Cy7_wVrQ

[newtothis]

Re: Toshiba 40L1333 Led Backlight Mod

Alu tape won't really help as the LEDs are directional very little light will be used in reflection and rebound. The LED's will need to be diffused and spread somehow.

I thought about doing exactly what you have but became stumped upon the issue you are now facing

[stj]

Re: Toshiba 40L1333 Led Backlight Mod

i know someone who has done this - i'll ask them the detail.

btw, where did you get 5m roll's for £6 ?

[newtothis]

Re: Toshiba 40L1333 Led Backlight Mod

i know someone who has done this - i'll ask them the detail.

btw, where did you get 5m roll's for £6 ?

I got 5m for £4 lol

Ebay auction

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

i know someone who has done this - i'll ask them the detail.

btw, where did you get 5m roll's for £6 ?

It was off ebay pal.

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

Alu tape won't really help as the LEDs are directional very little light will be used in reflection and rebound. The LED's will need to be diffused and spread somehow.

I thought about doing exactly what you have but became stumped upon the issue you are now facing

Hmm wander what can be done then, I have lots of spare smashed lcds that I could use parts from just waiting for the video to process then you can see the issue.

[tom66]

Re: Toshiba 40L1333 Led Backlight Mod

I honestly expect eBay LEDs to last even less time than the original ones. They just... don't last.

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

I honestly expect eBay LEDs to last even less time than the original ones. They just... don't last.

Ive had some in my lighting set up in my room which is another video on my channel, its been working for months now just hope to get some more life out of this pos.

[Dang]

Re: Toshiba 40L1333 Led Backlight Mod

Your video is marked as private so I can't view it, it would be good to see so can you make viewable for all please?

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

The video is still uploading it will be another hour or two depending on how my wifi feels, I will update the thread when its ready, sorry about that everyone.

[Dang]

Re: Toshiba 40L1333 Led Backlight Mod

Arr right you are, it's all good and thank you. I'm in this position my self right now and have seen these LED strips on Evil-bay so to see them being used like this will be very interesting and good useful info, thanks.

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

Arr right you are, it's all good and thank you. I'm in this position my self right now and have seen these LED strips on Evil-bay so to see them being used like this will be very interesting and good useful info, thanks.

No problem its really hard to explain it in words, the video demonstrates alot

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

Video is uploaded please feel free to watch and comment thank you.

[tom66]

Re: Toshiba 40L1333 Led Backlight Mod

Just a note: the LED driver board ought to draw the same current as LEDs connected directly, if all else is the same. The driver board will output a high voltage, low current; but it will draw a high current at a lower voltage to do so.

Power must be conserved, so power in = power out - losses in conversion.

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

Just a note: the LED driver board ought to draw the same current as LEDs connected directly, if all else is the same. The driver board will output a high voltage, low current; but it will draw a high current at a lower voltage to do so.

Power must be conserved, so power in = power out - losses in conversion.

Ahh right ok I got it backwards then, either way the psu now runs alot cooler with 3 output diodes on he 24v. Any ideas on how to sort that light issue Tom ?

[tom66]

Re: Toshiba 40L1333 Led Backlight Mod

Perhaps a diffuser from a 40" CCFL TV would work. As they are roughly similar in light output (bar-like light emitters, rather than spot-like)

Be mindful to avoid overloading the 24V output, as this might cause the transformer or primary side of the PSU to fail. Best way would be to characterise the current drawn per strip, and if this is too high for 6 strips, you should reduce the load by removing a strip or adding a series resistor.

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

Perhaps a diffuser from a 40" CCFL TV would work. As they are roughly similar in light output (bar-like light emitters, rather than spot-like)

Be mindful to avoid overloading the 24V output, as this might cause the transformer or primary side of the PSU to fail. Best way would be to characterise the current drawn per strip, and if this is too high for 6 strips, you should reduce the load by removing a strip or adding a series resistor.

Alright thanks for the info I have a 40" Technika ccfl backlit that smashed I will open that up tomorrow and give it a go. Also I am going to add a series resistor will do the ohms calculation later to dim the leds slightly.

[tibimakai]

Re: Toshiba 40L1333 Led Backlight Mod

You need some diffuser sheets for sure.
How about, removing one of the strips from the two and placing it between the existing two? Basically, every strip to be equally spaces between each other?

[ReeceyBurger123]

Re: Toshiba 40L1333 Led Backlight Mod

Well everyone this time the project failed, as I damaged the outer bezel that supports the lcd, but I am going to properly plan this and use ccfl diffusers on top of the leds while using the original differuser this will optimise the light I have discovered. Early stages yet but definalty a future project to consider hopefully will sucessfully mod one of these soon. I will start a whole new separate thread as Im going to put alot more planning into this project.

[cossiejay]

Re: Toshiba 40L1333 Led Backlight Mod

video unavailable