LG 55 inch OLED TV Teardown - Page 1
Forum section: electronics / projects

author: tom66
author_rank: Super Contributor
timestamp: March 24, 2014, 12:57:18 pm
content: Latest generation of TV technology. 55 inch curved AMOLED TV.Notably, most of the power electronics are now on the display panel, so good luck fixing them if something goes wrong there. (Under the heatsinks for the SOURCE PCB, running along the bottom of the panel.)

author: Towger
author_rank: Super Contributor
timestamp: March 24, 2014, 02:14:11 pm
content: "Check that the latch was properly assembled by pounding on it."

author: Stonent
author_rank: Super Contributor
timestamp: March 24, 2014, 03:33:59 pm
content: "WIFI ASSAY"

author: station240
author_rank: Unknown
timestamp: March 24, 2014, 09:55:19 pm
content: What a strange TV, carbon fibre back and other strange styling, but as it costs $8,000 and isn't even available in this state (SA), I don't expect to see one much less buy the thing.I really don't like the fixed in power cable and AV inputs, seems like it's designed to get broken.

author: Towger
author_rank: Super Contributor
timestamp: March 24, 2014, 10:31:59 pm
content: They are €5,300 in Ireland, but if you want to spend more money Harvey Norman (Ireland) will sell you one for an extra €200.What are Harvey Norman like in Oz, Dave only talks about Dick Smith? They setup here a few years ago and have lost a fortune and are more expensive for most items, unless you manage to see the odd good deal in sale. I will say nothing about their annoying advertsEdit: Typo

author: andtfoot
author_rank: Unknown
timestamp: March 24, 2014, 11:41:45 pm
content: Quote from: tom66 on March 24, 2014, 12:57:18 pmWhere does it show that? I'm just seeing the biggest board on the back with the yellow transformers...

author: tom66
author_rank: Super Contributor
timestamp: March 25, 2014, 12:35:28 am
content: Quote from: andtfoot on March 24, 2014, 11:41:45 pmThat's just the power board.I am referring to the OLED drive electronics which will be the 2nd most common failure in my opinion (only behind the power board.)Plasma TVs have 95% of the power electronics external to the panel, so a fault in such is repairable. LCD is about 80% external, less repairable with newer panel faults. OLED looks to be maybe 10% (just a set of DC-DC converters is all.)

author: Stonent
author_rank: Super Contributor
timestamp: March 25, 2014, 06:18:58 am
content: It's all fine and dandy until one day you decide to move house and you tossed the box and you break your screen.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: March 25, 2014, 09:14:05 am
content: Is the word "assy" actually used normally, or was it a goof-up by the narrator not saying assembly? And what are "1.5 pi screws", notated with a contour integral symbol?

author: dexters_lab
author_rank: Unknown
timestamp: March 25, 2014, 10:27:27 am
content: i couldn't bare listening to the narration, i had to mute it!

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: March 25, 2014, 06:38:45 pm
content: The product is one big wank.So you have to first create a curved work surface before dismantling it, what a fail. If you get the work surface wrong you end up breaking the display? They don't provide a platform in the packaging?He uses a power screwdriver to undo 1mm screws?? And then uses it again to blast in those screws for the USB camera??? What an idiot.For $8000?? And you get 55inches? I'd much rather have a projector. And why is the screen curved?This video and this product casts some serious doubt on the minds at LG. The product manager must have some compromising pictures of the LG CEO or something to get that product made.

author: tom66
author_rank: Super Contributor
timestamp: March 26, 2014, 11:55:33 pm
content: The big "thing" with AMOLED is that it has essentially zero black luminance, so it looks really good on dark scenes. Even projectors (aside from true laser projectors) can't manage this.But PIONEER did this in 2008 with a prototype Kuro plasma, and they got damn near it for production models (Kuro 9.5G) before throwing in the towel. Panasonic and Samsung also managed very dark black levels with their modern 2013 panels. Plasma is overall more reliable and in the instances where one does fail repair is often reasonably simple and cost effective.The problem with plasma is it's just not energy efficient but compared to OLED it only uses 2x the power - and costs ~1/4 the price. The 55" AMOLED uses about 200 watts full white, 60" plasma uses 300 to 350 watts.The early generation AMOLED screen is curved because of a design limitation, the panel temperature varies across the surface and so it likes to expand and potentially crack, by bending it into a curve it is restricted and the risk of failure is reduced.OLED's the future but I wish they wouldn't dump plasma so quickly, OLED has a lot to prove before it reaches mass market potential.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: March 27, 2014, 12:19:16 am
content: @tom66, I'm not sure what zero black luminance means, but I understand what you're saying. That it is a key metric for those wanting the purest reproduction. But do film makers and editors view their works via AMOLED? Do movie theaters have AMOLED? I'm merely pointing out that I really wonder if AMOLED is the future because I've heard that for several years now and yet I hear about "problems" still. Most film makers look at their dailys via projectors. I would bet on color e-ink technology to be the future. It's low power, they can be designed to be very durable, you can roll them up now, puncture them and they still work. Visible under multiple lighting conditions and have great viewing angle.Big, power-guzzling, expensive, fragile, finicky technologies won't scale into the future.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 27, 2014, 12:52:48 am
content: I have a Galaxy Gear watch (got on sale for $150) that uses an AMOLED display. OLEDs are efficient as long as the content is mostly dark with light lettering, exactly opposite to LCDs that are most efficient black text on white background, which allows for a very low backlight setting and still be very readable.I think the future is going to be TDM (time division multiplexed, specifically the RGB backlight) LCDs. The color filter layer is only about 30% efficient, so TDM would cut the power usage to about 1/3 if the power usage of the added processing electronics is negligible. The tradeoff is that the LCD must be very fast to avoid flicker.

author: tom66
author_rank: Super Contributor
timestamp: March 27, 2014, 01:25:37 am
content: I was under the impression that most editing of films is often done on CRTs and professional plasma monitors which have very low black luminance.TDM LCD - "blue phase mode" - is an interesting idea but doesn't get around the fundamental limitation of an LCD panel bleeding light which for me is the only major limit for LCD. Response time is now so good you cannot see it. But they still bleed light.LED-LCDs are great efficiency wise -- you can't beat a single light source + LCD for efficiency (60" LCD <90W power usage) but honestly, if I am paying the electricity bill, the efficiency of the display panel is minimally important to me, given I only watch 5 hours a week of pre-recorded content, nothing live. It's maybe important for people who watch TV far too much. But they probably don't care so much about the picture quality.Another issue with AMOLED which needs to be solved: currently each source driver (for driving the TFTs of the OLED panel) is a linear (class AB) amplifier - this means it dissipates heat most at 50% brightness. Worst case image is 50% grey for power dissipation in source drivers (where the power electronics is, bonded to OLED panel.) Effectively that's 100 watts in the source drivers and 100 watts in the panel itself -- we're talking about 100 watts across about 16 chip-on-glass ICs, each managing 1/16th of the image (360 lines/driver) with a fairly small heatsink - I hope they have good thermal management...! They will hopefully move to a time-pulse density modulated display soon (plasmas use this trick) but the trouble is, the display has a lot of capacitance so this limits the response time.I'm still waiting for a cinema to come out with a full LED cinema screen. I'm sure it's possible it's just going to be insanely expensive to reach the 2K or 4K resolution required.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 27, 2014, 02:16:52 am
content: If OLEDs are anything like regular LEDs, LDO linear current control can be very efficient. The PSU is set to a voltage just above the maximum voltage drop of the LED and the linear pass transistor only drops a small percentage of the voltage.High efficiency TVs would really appeal to those who use them as really big monitors. That would become more common once 4K becomes mainstream, since it would be like having a 2x2 array of 1080p monitors without borders.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: March 27, 2014, 05:08:09 am
content: Quote from: tom66 on March 27, 2014, 01:25:37 amBut not zero black luminance. You are probably right, My point was just that if the original was shot and produced and edited using some technology "inferior" to AMOLED then how good will it be? Is the cinematographer making sure that his shooting will look great with zero black luminance AMOLED displays?To me all big screen tvs seem like old technology. They require lots of raw materials, they are a big recycle mess, they are heavy and power hungry. Without subsidies and reduced tariffs and low wages, I don't think the big screen tv market would still exist.But I've only got a projector and would never go back to a little "big screen" again. Projectors and e-ink are the future. And LED and laser technology is making projectors cheaper and better. I'm not sure of the latest e-ink technology but the displays are in more and more consumer products. That foothold will help to get more R&d funding.

author: tom66
author_rank: Super Contributor
timestamp: March 27, 2014, 11:53:23 am
content: CRTs have zero black when properly adjusted. Some plasmas hit black levels so low the human eye can't tell the difference except in a pitch black room. I think the thing is with low black illuminance is it really can only make the image look better as long as it's done right. It's not as if the displays will cut off the grey beyond a certain point - they just remove that base illumination which washes out the other colours.But you're right, it'll take some time for it to be the accepted industry standard. It really does immerse you in a good film - Gravity for example - I tried watching that on an LCD and I could not! It just didn't look right.Colour e-ink is just a dull LCD with memory. It needs a frontlight to work properly. Don't see how it solves anything for now. Also too slow. Might improve, but it's probably best on e-readers, watches and low power devices.Projectors are cool - currently they burn bulbs too fast for my taste. LED/Laser will improve this (currently too pricey), but they still need a fair bit of space and setup. But it is a good solution for those prepared to do it.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: March 27, 2014, 05:54:14 pm
content: Good point about the human eye's ability to detect those subtleties. And maybe the human mind to even care.Yes e-ink's got a way to go but every time I revisit the state of the art I see progress. But with OLED it keeps looking like big technical issues, including manufacturing and time to market problems. That screen in the video looks more like a proof-of-concept than a consumer device. And I think LG have decided to sell the proof-of-concept to consumers (albeit a crazy price) to keep the product/project alive. Otherwise the higher-ups would have pulled the plug. Or they've put too much into to turn back now? A little of both?QuoteSeveral years back I bought a bulb-less LED and it's been great. But I'm neither audio or video afficionado. The only reason I can see that projectors haven't seen much, much more penetration into the market is because they are a very disruptive technology. A lot of the issues are getting worked out and I haven't even visited current projector offerings lately.The big companies have invested heavily into manufacturing big screens and they need to recoup more money before the projector is let out of the bag. But projectors are starting to creep out of "asian" markets.