EEVblog #465 - LED LCD Panel Teardown

Teardown Tuesday
What's inside a modern LED backlight LCD panel from a 27" computer monitor?

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[greencoder]

Beautiful at 28:30 and 20:56 and 21:12 .
01:16 The PCB
05:44 Removing the back plate. Viewing the white, light reflective back
06:43 LED-back-lit polycarbonate layer with etched dots to let the black light escape the inner total reflection

11:53 Diffusion layer
12:25 Brightness Enhancing Layer recycling the off-axis light

16:21 Some extra diffusion layer?
17:10 The cracked LCD panel
18:25 Driver chips for x-axis and y-axis
19:55 Removal of the frontal polarization layer
20:24 Back polarization layer, pixel close up with macro lens
21:11 Viewing the individual traces to the driver chips
25:24 Pixel and Subpixel viewed with microscope
26:27 Explainaiton and Summarization
28:43 LED backlight efficiency

[theSFCchannel]

That extra stuck layer (the dark one) you are trying to peel off with a knife is the Polarizing layer. BEST way to get it off so as not to damage the screen is to MASTK TAPE over the electronics to protect them then get a load of wet towels and SOAK the black layer of the BACK off the screen then after three hours you can simply peel away the polarizing layer.

[KN]

Dave, the regularity with which you upload your content never ceases to amazes me

[ronaldlijs]

Great video Dave, well produced and practically explained, well done! Keep them up, this is how everyone actually learns!

[AldoBr]

It is unreal the amount of complexity that goes into everyday appliances that I take for granted. Awesome teardown. I watch all your videos Dave, keep up all the good work!

[EEVblog]

Yes, that would be interesting with that many diodes in series!

[kevinkunst]

Just found this video and this channel and while I haven't yet had the time to watch this video in its entirety I couldn't help but smile from just hearing the enthusiasm and joy in your voice as you spoke about this teardown! I can't wait to fully watch this AND a bunch of your other videos!

[GeoffreyRanson]

This show literally changed my direction in life. I went from living in the world of software to jumping into the world of hardware. Im now going to be studying electronic engineering rather than computer science. I may still minor in computer science though. You can never have enough knowledge. Please keep doing what your your doing Dave, this is the best show on youtube.

[ElectronicTonic]

I've taken apart lots of CCFT LCD monitor panels, and they had 2 directional diffusers - one for X, one for Y.

[shamanjoe]

Yes please, a follow-up video on the diffusion. Looks super neat!

[theobserver]

Dave, it was fun to realize, that 5 years after your video, I did this teardown, exactly the same way you did, but only with a broken laptop LED LCD screen (which has the same structure, only with smaller parts). I also lighted up only one part of the LED stripe, and tried to realign the layers to see, how they deal with the light. After my experiments, I tried to lookup some videos, which could explain some things more in detail, and landed up on your video :D It's like watching my discoveries in a replay :D

[BineySaurus]

The most terrifying trace spacing I have ever seen at 21:40

[rinusborg]

Hi Dave, I was puzzled by the the types of materials in an edge it TV. Your explanation is very, very good. I needed to see what the order was as some of the sheets can be assembled in the incorrect order. I repaired a TV that could not be watched as it was incorrectly put back together.
Some TVs have more or less diffusion materials.
I solved it by watching your very simple to understand EEVblog #465 - LED LCD Panel Teardown.
I do know that the wrong order explains also the extra diffusion sheets. It is to prevent refraction when two smooth surfaces are placed on top of each other. so the extra diffuser acts as a separator. A pebbled surface prevents this. It is also the reason they are often very this as diffusion is only their second purpose.I assembled an 80" incorrectly and the large patterns an wrong side up/down was not seen until you turned on the TV.
Thanks for the video, I have saved it for later sharing.
Rinus (Canada) ("Mommy, where is my mommy, they've taken her away!" - Just for you Dave.)

[fuzzybobbles]

Can you light the whole LED strip? Also how to connect it up and what current and voltage to use. That I could use as a cheap source of light for camping trips and some solar panels to charge the batteries during the day. Tell us more Dave please. :o)

[Aussie]

Thats a really good autopsy on a LED LCD panel!. i am waiting for a damaged big screen LED TV to show up for tear down, I am watching this on a Sharp Aquos 3D LED LCD with its 4 color pixels and I would love to tear into a dead one some day to see how it work!

[allenpan]

Chi-Mei is one of the biggest LCD Panel manufacture, they also produce for LG/Sharp/Samsung ...etc

[ChipGuy]

Your teardowns are always amazing, keep it up. Wohoo !

[ChiefPFF]

In a previous job I once made a pretty kickass UV exposure box from a flatbed scanner, a tanning lamp and the diffusers from a broken LCD.

[MauroTamm]

The led strip with the complete diffusion /reflective white bacgroudn could make a quite nice smooth light source - as a ambient light or placed in a picture frame and perhaps colored plastic in front or some glass collage in front - and its quite low power.

Could do for a nice weekend project and nightlight.

[gamccoy]

I thought this vid was going to be a real yawner but I was surprised at how interesting that was. I never knew about the amount of effort going into the diffusion and guiding of the light paths.