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LG Plasma Panel tweaks for better blacks.

259K views 1K replies 191 participants last post by  Dirtgarry 
#1 ·
For the last few months there have been a few brave individuals who have begun the task of technically improving the black levels on their LG plasmas by tweaking a few pots on the actual boards inside the sets so I believe a dedicated thread should be started.

Mind you, all tweaks are at your own risk, will void your warranty and you could be exposed to lethal voltages
, but the procedure could be rewarding.
And of course AVSFORUMS nor the posters can be held legally responsible for any mishaps, panel misbehavior and non-reversible disasters, proceed at your own risk.

Quote:
Originally Posted by rob80b /forum/post/21562480

http://en.wikipedia.org/wiki/Tweaking


"Tweaking

From Wikipedia, the free encyclopedia


This article is about hardware and software tweaking. For the drug-induced behavior, see Stereotypy. For other uses, see Tweaker (disambiguation).


Tweaking refers to fine-tuning or adjusting a complex system, usually an electronic device. Tweaks are any small modifications intended to improve a system.


In electronics, it is a synonym for "trimming." Analog circuit boards often have small potentiometers or other components on them that are used to calibrate or adjust the board as a service procedure: the small insulated screwdriver used to turn them is often called a "tweaker."
"

The posts that started it all


03-19-11, 12:23 PM
Quote:
Originally Posted by Turrican4D /forum/post/20174285


@rpauls

Simply put (my tuningmanual is in german), you have to turn the potis named "Set_UP" and "Set_Dn" clockwise until you get pixelmissfires and/or artifacts in the highlights.


Also it would show to help a minimum of MLL to turn the poti names "VY" completely counter clockwise and the poti names "VA" completely clockwise.


But beware! You lose your warranty!


And do it slow, in case you run in a safety shutdown of your TV.

05-24-11, 10:40 PM
Quote:
Originally Posted by Mauri /forum/post/20483346


All the documentation is available in U.S. english



This is the complete LG plasma Panel Alignment Book (quick reference), latest version (03/31/2011): http://136.166.4.200/contents/Displa...t_Handbook.pdf


LG U.S. got the explanations from the complete Training Manuals of many plasma models, and they have arranged that book. Read it carefully before start to do something. If you have never done such things before, it is better to have a look for an expert TV tech friend. The right way to arrange the tuning work, is to use a big mirror. Put the TV screen in front of the mirror and look at the mirror during tuning. Use only full plastic screwdrivers (easy available and very cheap) and remember that there could be high voltages on some circuits, so be careful. It is like to work on tube amps, you know? Only a bit more difficult because you are working on big screens, and that's the reason why you need to use a mirror (for safety reasons, at first).


For many plasma models, complete informations and training manuals (very useful) are also available. On this page there is the list: http://136.166.4.200/SubPages/Directview_PDP.htm


clic on the model you are interesting for, and on the left of the new page you will find the docs available for download. There is even the new 50PZ950 and PV450 models, as well as the PK950 and 750.


With such informations available, I think LG plasma are well worth a look. I'm going to buy a 60PK980 (same of 60PK950) during the next days. Now it has a very good price in my Country (1170 euro including shipping) and it is the right time to buy it. I'm not interesting in the actual 3D stuff.


'sorry for my bad english, and best regards from Italy


Mauri

05-21-11, 06:12 PM
Quote:
Originally Posted by Turrican4D /forum/post/20469656


No, it does not hurt the brightness of the picture. It only affects MLL.



The potis inside the TV are labeled with their names.


1. Start a Blu-ray-Disc


2. Turn "Va" full throttle clockwise


3. Turn Vy full throttle counterclockwise



After that turn "Set_Up" clockwise untill you get noise in very bright moviescenes. Turn a microamount counterclockwise untill the noise disappears.


Finally turn "Set_Dn" clockwise untill you get pixelmissfires. Turn a microamount counterclockwise untill you dont' get new pixelmissfires.


Congratulations to your new KURO (8G or 9G) MLL.


added Jan 5th 2012
Quote:
Originally Posted by wiremite /forum/post/21407861


I did get a kick out of tweaking my brother Bob's LG. Seeing in real tiime the grey bars turn pitch black was very satifying. The black level definitely matches (exceeds!?) my ST30 black levels. That a little analog knob could have so much control seems comical when you consider the advanced technology that gets poured into these panels.

Quote:
Originally Posted by Turrican4D /forum/post/21223473


Hehe



Even on my own PK350 I tried very different approaches. One method included Va full clockwise and the one I am using at this moment is the opposite-> Va full counterclockwise.



Each method has consequences for the other pots. If I set Va full clockwise, I cannot go so far with Set_Dn and I can't use Vs-Boost.


If I set Va full counterclockwise, I have more headroom for Set_Dn but a little less headroom for Set_Up but I can boost Vs a little bit, to make up for that, so that I have again the headroom for turning Set_Up more clockwise.


Generally are Set_Up, Set_Dn and Vy the only three of the seven pots, which have a direct influence on the black level.


Also generally there are three pots, which can cause vertical noise patterns-> Vs, Set_Dn and Vy.


One could say with Va full clockwise the danger of getting pixelmissfires out of a black screen to a bright screen (Disney Castle on Disney BDs for example) is not so high as it is with Va counterclockwise, but with counterclockwise the chance of getting missfires during an actual moviescene is lower.


If one decide to better just get some little pixelmissfires sometimes for getting even more out of his panel mll wise, he could experiment mit the pot VSC, cause with VSC at the right sweet spot, the ability of your panel to erase false fired pixels can be sped up.


VZB also has a sweet spot, that you can find the best with halflit secenes leike the one in "The American" ight at the sturt, when Clooney lies there with his soon to be dead girlfriend-> You turn VZB full counterclockwise: The picture will have lost its depth. Now you move slowly(!) micrometer for micrometer clockwise just to the point, where this moviescene jumps back to depth and contrast.


This is what you might get with the seven pots, if you set it too much clockwise or counterclockwise:


VZB____: noise (clockwise) or dullness (counterclockwise)

Vs_____: noisy whites/pixelmissfires (clockwise) or dullness/extreme pixelmissfires (counterclockwise)

VA_____: none obvious erros but possible pixelmissfires with static fullgreen screen (clockwise)

VSC____: None obvious errors or artifacts

Vy_____: noise/less MLL (clockwise) or better MLL (counterclockwise)

Set_Up_: pixelmissfires/better MLL (clockwise) or bad MLL (counterclockwise)

Set_Dn_: noise/better MLL (clockwise) or bad MLL


Added Nov 30th

http://www.avsforum.com/avs-vb/showt...php?p=21281625



Quote:
Originally Posted by harvro01 /forum/post/21281625


Just wanted to share my experience in doing these adjustments, I was hesitant to do it in the first place as I was concerned about what was actually happening, however I downloaded and read the factory manuals which explained a lot.


I have a 60PK550


The end result is WOW, what a difference. A fair bit of work tweaking various pots (I did all 7) but the end result is worth it. WAY deeper blacks, no difference in terms of noise or pixel misfires.


My experience with the various adjustments (and in the order I did them, following the factory LG sequence from the manual) is as follows:

VS: Counterclockwise results in some noise in lighter pixels and lowers MLL, turning clockwise corrects the pixel noise and raises MLL but too far clockwise, and my set just shuts off and will not restart. In the end, I only adjusted this pot a hair clockwise to get rid of the white pixel noise.
VA: Clockwise lowers MLL.Did not cause any misfires for me so mine is cranked fully clockwise.
VSC: Made no appreciable difference one way or the other to anything so mine is left at centre position.
Vy: Turning clockwise results in higher MLL, counterclockwise results in lower MLL. Does not appear to introduce any artifacts or noise so mine is cranked counterclockwise.
Set_Up: Clockwise lowers MLL. I've read that turning this fully clockwise can cause some pixel misfires, however this does not appear to be the case with my set, so mine is fully cranked.
Set_Down: Clockwise lowers MLL, however fully clockwise for me also introduces may pixel errors, pixels not resetting after changing colour, so I had to back mine off a bit from fully cranked clockwise until these disappeared.
VZB: Appears to affect the 'dullness' of the overall image, minimal effect on MLL that I can tell. Clockwise seems to give the picture more 'pop', while counterclockwise gives a more washed out image. Mine is cranked fully clockwise.


As others have said, I'm sure individual results differ, but for me, the few hours tweaking these pots and looking at test images and videos are well worth it. I would say that black letterbox bars are more or less gone and blend into the bezel now. Images seem to have way more pop and depth. I have never had any issues with image retention with my set (14 months old now) and nothing seems to have changed in this regard with the tweaks.


Initially, I was trying to follow the technical manual and adjust VS and VA to the voltages listed on my panel sticker as suggested. Mine were slightly off from the sticker. This however raised the MLL and so I just fiddled with pots to see what happened in the end. I'm glad I did.

Added December 8th 2011 http://www.avsforum.com/avs-vb/showt...php?p=21314111

Quote:
Originally Posted by walt73 /forum/post/21314111


I did the tweak on my 50PK550 (North American model, Mar 2010 build) this morning with stunning results (so far).


Following the tips in this thread, I adjusted only VY and Set_Up. Factory presets were 4 and 1 o'clock respectively; I started by turning these to 2 and 7 o'clock (i.e. Set_Up maxed out). Wow! Massive instant improvement! Turned TV off and allowed to cool 45 mins. TV back on, again v deep black level ... BUT suddenly saw too many misfiring pixels (unacceptably noisy-looking picture).


I decided to proceed as follows: sit at my preferred view distance (lately 63") and then throttle back VY and Set_Up, not necessarily til absolutely no pixels misfired, but only until I judged the results to be tolerable in actual viewing. (I figured I was willing to trade off a certain amount of picture noise for better black level -- exactly how much noise, to be discovered by experiment.)


I did all tests in 72Hz mode since on my set the MLL is visibly better than it is in 60Hz. I know in theory it should be the other way round but I'm not the first to report this on the 50" model of the PK550. To get the colour bar patterns, played on PS3, converted to 1080p24 I used an outboard video processor (DVDO Edge); I also tried some HD cable movies and of course Blu-rays.


Eventually I settled into VY 3 o'clock and Set_Up 5 o'clock. If I look very very hard (from 63" away) at the blue and red on the colour bar pattern I can still sometimes barely see the occasional misfiring pixel. BFD; black levels are now insanely good, and besides, I can't see the misfiring at all during a movie. With my bias light on (GE 20W Daylite flourescent strip 6500K) black appears almost as black as the bezel. I don't have a light meter so I can't say what the MLL is exactly. Suffice it to say it's pretty freakin' black. If I wanted to I could probably watch this set in the dark. (I couldn't before the tweak; MLL was way too high for that.)


I watched half of Sin City Blu-ray and was utterly floooooored by the new improved contrast. Other PQ-demanding films which instantly went from blah to wow: Dracula (Coppola), The Spirit, dark scenes in Pirates/Caribbean #1. Can't wait to try more.


I'd like to say a huge thank you to the contributors to this thread. What an awesome tweak. I will post back if I run into any issues in future.


PS: 50PK550 owners: As you remove the back cover watch out for the mini screws around the component video inputs; they're easy to overlook. Ditto for the lone screw near the HDMI ins and the one by the power socket.

added December 20th 2011

Quote:
Originally Posted by rpauls /forum/post/21373555


When my 60PK540 was new it was measuring an MLL of .018 FtL for 60Hz inputs, which I was pretty happy with. However, now after a year of use I noticed the black level had risen quite a bit. Last night I measured it at .036 FtL (Never heard of LG MLL rise issues, so not sure what's up). In any event, I decided to try this pot tweak. The results were amazing.


I followed the LG training manual exactly.


First I measured all the voltages Vs, Va, Vy, VSC, VZB, and all were very close (within 1 volt) of the number on the panel sticker so I left them alone.


Then I got out the scope and locked on to the waveform as explained in the training manual. The Set Up portion of the waveform was supposed to be 280V, mine was measuring nearly 350V, the Set Down was supposed to be 140us long, mine was only 125us. I adjusted both pots until the readings were as close as possible to specs. I could only get Set up down to 290V even at full clockwise excursion, but I could get set down to exactly 140us, and both ramps in the waveform looked just like the picture. (Note, for all these measurements the set must be showing a full white 100% screen for at least 15 minutes)


Well I went back out front, turned off the whitewash and I the screen was so dark I thought it was off!


I got my probe out and it measured .008 FtL. Needless to say I am very happy with the results.


So in summary, I did not touch any of the 5 voltage pots, they were right on from the factory. I adjusted set up and set down only exactly as described in the manual and the results are amazing.


I will proceed to do a full grayscale and CMS calibration tonight and compare with my results with my measurements before the procedure, but I am very optimistic. The picture looks great.


Rich
 
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#552 ·

Quote:
Originally Posted by boba23 /forum/post/21415909


Alright, this is basically what I did tonight to my 50PZ950, just wouldn't wanna wait any more. Guess my set has max 100 hours now.

What can I say .... the results are fantastic. Black is as black as black can get I'd say. Black bars in 16:9 movies are now ... well black, not dark gray anymore.

I turned Set_up full clockwise, adjusted Va full clockwise, Vy full counterclockwise ... went ahead and also turned Set_dn clockwise well, at least a quarter, didn't see any pixel missfires ... but I stopped there, maybe I could have turned Set_dn even further, but the result was so good already.

Thanks everyone for this thread :)

PS: also no missfires when powering on the TV, though I didn't have it off for more than 30 minutes, we'll see what happens tomorrow morning.


boba

Sounds good boba,


I may try adjusting the Vy and Va this weekend, although I've had no misfires on turn-on today.

Although, and this might just be my imagination, I thought the blacks looked a little less black tonight, still very black though more like my brothers ST30.
 
#553 ·
ok, I spreaded the word and I got two people to try.


One guy with PK550 had a great success. set_up to max clockwise, vy to max counter clockwise. He only gets misfires after a cold start for 5 minutes. After that, all's well.


The other guy was not so lucky. He has PG20 to which I immediately thought "Oh, Rob80b's panel!" but no, it wasn't PG20/25 like he has, but actually a G1 panel which strangely also shares the same name.

http://136.166.4.200/contents/Displa...T-HANDBOOK.pdf


I asked him to locate VA and VS, but he couldn't. He could only find set_up,set_dn,VSC,VZB, and VY.


According to him, he turned set_up fully clockwise, but strangely no effect. Fully counter-clockwise, still no effect.


Set_DN : Turning clockwise, he suddely gets a white splash light. I knew he pushed it too far. Turning counter clockwise, messy misfires, yet still no obvious changes to the black.


VY : Just varies the amount of misfires shown, but not really doing anything to change black.


I'm curious as to how the G1 behaves, but without actually owning one, I'm helpless. (I only did it on my PT350)
 
#554 ·

Quote:
Originally Posted by th3third /forum/post/21411146


I have the 60PZ950, which isn't listed, nor is the 60PK950. If I wanted to double check voltages with a meter, where can I find the proper specs (or a safe range) for my model.

For the 60PZ950 check under 60PZ850. They seem to use the same "60R3" panel. In fact, if you look in the Panel Alignment document, it says 60PZ950 together with 60PZ850, 60PZ750 and 60PZ550.


Btw, the situation is similar for the 60PK950. It uses the same "60R1" panel as the 60PK750, according to the documents.
 
#555 ·

Quote:
Originally Posted by KOF /forum/post/21416240


ok, I spreaded the word and I got two people to try.


One guy with PK550 had a great success. set_up to max clockwise, vy to max counter clockwise. He only gets misfires after a cold start for 5 minutes. After that, all's well.


The other guy was not so lucky. He has PG20 to which I immediately thought "Oh, Rob80b's panel!" but no, it wasn't PG20/25 like he has, but actually a G1 panel which strangely also shares the same name.

http://136.166.4.200/contents/Displa...T-HANDBOOK.pdf


I asked him to locate VA and VS, but he couldn't. He could only find set_up,set_dn,VSC,VZB, and VY.


According to him, he turned set_up fully clockwise, but strangely no effect. Fully counter-clockwise, still no effect.


Set_DN : Turning clockwise, he suddely gets a white splash light. I knew he pushed it too far. Turning counter clockwise, messy misfires, yet still no obvious changes to the black.


VY : Just varies the amount of misfires shown, but not really doing anything to change black.


I'm curious as to how the G1 behaves, but without actually owning one, I'm helpless. (I only did it on my PT350)

Hi KOF


As I noted while doing my PG25 I got "slightly" better blacks with the Set_up, maybe a few steps on the gray scale, with Set_dn all hell broke loose.


Maybe he didn't realize Vs and Va are on the power supply, a different board, but both these pots can shut down the set if turned too much.


It was because of my experience with my PG25 I was more cautious with the PX950 and only adjusted the Set_up, also because the PX was all ready much better than the PG I was not prepared for the vast improvements over it's little brother.


Interestingly enough I'm not getting problems with start-up anymore.
 
#556 ·

Quote:
Originally Posted by rpauls /forum/post/21406115


harvo01,

What is your input source when achieving this level? 24fps or 60?


I can not get below .016 of 24fps, though .007 and even lower to the point of being unmeasurable with my equipment is possible on 60Hz at the expense of a few misfires. Isn't it amazing to see the black level just drop before your eyes to the point where it looks as dark as the frame ;-)

Checked black level differences between 24fps and 60 last night and could not perceive any difference?
 
#557 ·

Quote:
Originally Posted by rob80b /forum/post/21416228


Sounds good boba,


I may try adjusting the Vy and Va this weekend, although I've had no misfires on turn-on today.

Although, and this might just be my imagination, I thought the blacks looked a little less black tonight, still very black though more like my brothers ST30.

So, seems everything is still good. Asked my GF to check for pixel missfires when turning on the set in the morning. She didn't notice anything, though I am not sure that she's as sensitive to the perfect picture as I am ;-)

Anyway one more thing I noticed yday after tweaking. The blacks while watching cinemascope with black bars are really incredibly dark ... if you watch closely you'll notice that the black in the actual video content is even darker than the cinemascope black bars .... how's that? Is that normal, because I can't imagine this is a black level thing. If the set can produce such incredible blacks for the real video content, why do the bars look just a tiny bit lighter? Is this a general thing about those cinemascope bars?


boba
 
#558 ·

Quote:
Originally Posted by boba23 /forum/post/21417223


Anyway one more thing I noticed yday after tweaking. The blacks while watching cinemascope with black bars are really incredibly dark ... if you watch closely you'll notice that the black in the actual video content is even darker than the cinemascope black bars .... how's that? Is that normal, because I can't imagine this is a black level thing. If the set can produce such incredible blacks for the real video content, why do the bars look just a tiny bit lighter? Is this a general thing about those cinemascope bars?


boba

Funny you should mention that, I noticed the same thing last night and put the film on pause to verify, the adjacent black to the bars was definitely a tad blacker, totally the opposite before tweaking, remember also that all not films are equal in black levels.

But as you say the black bars are incredibly dark (black) now, for more than 90% of viewing they are not visible in a dark room.
 
#560 ·

Quote:
Originally Posted by rob80b /forum/post/21417056


Interestingly enough I'm not getting problems with start-up anymore.

Just to double check, overnight dropped the thermostat and opened a window a bit to cool the room (probably mid-60s F, the room that is) gotta love these Canadian winters, sure enough pixel misfires with turn-on this morning.

I will have to take a reading of the ambient temperature to see at what point they occur.
 
#561 ·

Quote:
Originally Posted by bhazard /forum/post/21417772


This is why I can't wait for large OLED screens to become afffordable. The screen on my Galaxy Nexus is so black you cant tell where the screen ends in the dark. Its a really cool thing to see.

But will they achieve that organic image quality we get with plasma?
 
#563 ·
Haha, not all OLEDs are created equal. My brother just got Samsung Galaxy S II HD LTE and with protection filter on, I thought even my modded PT350 had better black. My brother was throughly disappointed too, as he was originally going to get regular S II which has far better black than this one does.
 
#564 ·

Quote:
Originally Posted by rob80b /forum/post/21417822


But will they achieve that organic image quality we get with plasma?

They are currently the only display technology available with the least compromises, that's for sure.


Of course, unlike the others, I do not really go ORGASMIC (bad pun) over them yet because I think even plasmas stink on motion blur compared to my Sony FW900 and Wega, and OLEDs stink even more because they are sample and hold based. If the plasmas can get over 200cd luminance with minimal APL, I have no need for OLEDs as I mostly game on my displays.
 
#565 ·

Quote:
Originally Posted by rob80b /forum/post/21417799


Just to double check, overnight dropped the thermostat and opened a window a bit to cool the room (probably mid-60s F, the room that is) gotta love these Canadian winters, sure enough pixel misfires with turn-on this morning.

I will have to take a reading of the ambient temperature to see at what point they occur.

Yeah, living in Toronto sucks when it comes to black tweaks lol. I thought I was going well with Panasonic GT30 black but then it snowed and misfires ruined my picture, so I had to back off and only maxed set_up and dancing pixels were still there. The next day, things have warmed up and I was able to push a bit more.
 
#566 ·

Quote:
Originally Posted by rob80b /forum/post/21417078


Checked black level differences between 24fps and 60 last night and could not perceive any difference?

my 50pk550 doesn't exhibit perceivable black level changes for 24p and 60p. From looking at the screen in the dark its essentially the same. I'll bring out my cheapo spyder 2 this weekend to try and quantify the black level difference if there's any. The spyder 2 probably wouldn't be able to read below 0.1 cd/m2, but if the black level doubles then the meter should be able to detect that.
 
#568 ·

Quote:
Originally Posted by petiteface /forum/post/21419511


I use a Spyder2 for calibrating my monitor. Is is possible to calibrate a plasma TV with it? I have a Zenith 60pv220 (same as the pv450).

I've calibrated my 50pk550 and 42pq30 plasmas with the spyder 2. Its not the greatest, but definitely better than calibrating by my eyes. I use the HCFR software and AVS HD 709 DVD that's available for download on avsforum. The two threads below helped alot:
http://www.avsforum.com/avs-vb/showthread.php?t=737550
http://www.avsforum.com/avs-vb/showthread.php?t=1029594
http://www.avsforum.com/avs-vb/showthread.php?t=983943


I don't get the wow factor, but I have not switched between picture modes since I calibrated the Expert 1 settings on my plasmas. There is alot of time to be spent once u start diving into calibrating tvs, especially these LG plasmas with the strenous 20pt calibration. I think I tried like 10 different times to get to where I like the picture and comfortable to not change any more settings for the last 6 months. Calibrating tv is much harder than the computer monitor, because adjustments are made manually in the TV's picture settings at each IRE. There's also alot of calibration help in the LG pk550 owners' forum.
 
#569 ·

Quote:
Originally Posted by Voz /forum/post/21416751


For the 60PZ950 check under 60PZ850. They seem to use the same "60R3" panel. In fact, if you look in the Panel Alignment document, it says 60PZ950 together with 60PZ850, 60PZ750 and 60PZ550.


Btw, the situation is similar for the 60PK950. It uses the same "60R1" panel as the 60PK750, according to the documents.

Thanks. I didn't DL and investigate the PZ850. I figured they were too different since the 850 has that Pentouch gizmo.
 
#570 ·
Well folks as we head into the New Year, I’d like to thanks everyone for contributing to this thread, we now have to keep an eye on the stability of the tweaks and to see if the we follow suite with Panasonics raising blacks.


Started this thread over a month and half ago but being a bit skeptical that the tweaks would be much an improvement over my stock PX950 (seeing it produced only minor improvements on my PG25, but an improvement all the same) it was only recently that I did the adjustments on my PX950 and was totally shocked with the improvement in black levels.

With the pot adjustments I believe it would be safe to assume that a tweaked current LG matches or may indeed exceed the other current flagship plasmas.


Trying to make a mental note of the current black level on my PX950, running an all black image in a darkened room my all black screen is just a perceptible notch above 0 black or where the panel goes to black after a few seconds when no image is displayed, the change is minimal.


I’d like to thank turrican and a few others for introducing us to the possibilities and xrox’s (research) treads and posts which have a wealth of information toward understanding plasma technology.
http://www.avsforum.com/avs-vb/showt...php?p=19515158
Quote:
Originally Posted by xrox /forum/post/19515158


Thread created as a place to post, learn, and discuss information regarding research into true ZERO black level pasma display technology. Also feel free to discuss the virtues (or not) of such technology.


I will update four sections later today


1 - Background Info

2 - Patents

3 - Journals & White Papers

4 - Media

Related Information (pre-reading
)

KURO Technology Explained
Panasonic NeoPDP Explained (when I have time...)
Rising Blacks Explained
Floating Blacks Explained
CEL explained (when I have time...)

All the best in 2012.
 
#571 ·

Quote:
Originally Posted by rob80b /forum/post/21421770


Well folks as we head into the New Year, I’d like to thanks everyone for contributing to this thread, we now have to keep an eye on the stability of the tweaks and to see if the we follow suite with Panasonics raising blacks.


Started this thread over a month and half ago but being a bit skeptical that the tweaks would be much an improvement over my stock PX950 (seeing it produced only minor improvements on my PG25, but an improvement all the same) it was only recently that I did the adjustments on my PX950 and was totally shocked with the improvement in black levels.

With the pot adjustments I believe it would be safe to assume that a tweaked current LG matches or may indeed exceed the other current flagship plasmas.


Trying to make a mental note of the current black level on my PX950, running an all black image in a darkened room my all black screen is just a perceptible notch above 0 black or where the panel goes to black after a few seconds when no image is displayed, the change is minimal.


I’d like to thank turrican and a few others for introducing us to the possibilities and xrox’s (research) treads and posts which have a wealth of information toward understanding plasma technology.
http://www.avsforum.com/avs-vb/showt...php?p=19515158



All the best in 2012.

You too Rob. Thanks for taking the lead in this. I would have NEVER tried this without the help of you, Turrican, et. al. As an aside, I too noticed pixel misfires during a cold start up (a frigid 52 in south fla), but they went away in about 2 min. I am so happy with how my LG looks that my next TV will be the 60 inch version, no matter who comes out with what. Sometimes, I find myself not watching whatever I am watching and noticing how black the blacks are.
 
#572 ·
Hey Guys, just thought I would chime in here real quick. Previously I had adjusted Set_Up and Set_Dn and was really happy with my black levels on my PV450. However, I had decided to try a Panasonic ST30 because of glare issues with my LG. Long story short, the Panny is going back for several reasons, and I still have my LG so I decided to check all the voltages and possibly re-tweak before putting it back up on the wall. Several of my voltages were off by quite a bit, especially Va AND Vs. By eye, it appears that black level actually got deeper by fixing the voltages, so I am really happy!


Thanks for all the posts guys, and for really filling this thread with valuable information.
 
#574 ·

Quote:
Originally Posted by Voz /forum/post/21426820


Would this oscilloscope be OK, coupled with a 10X probe rated for 600V?

http://www.rigolna.com/products/digi...s1000e/ds1052e


(50PK950, 502V p/p)

While I can't comment on that individual oscilloscope, to spend nearly $300 on an oscilloscope for only adjusting this one TV is not worth it- better off borrowing one or tweaking it yourself and using the extra money to get a professional calibration. You can adjust all the other voltages with just a multimeter and a screwdriver, and for set-up and set-down just adjust in whatever direction makes it darker until you run into misfires or other issues.
 
#576 ·

Quote:
Originally Posted by avfanatic1 /forum/post/21426898


While I can't comment on that individual oscilloscope, to spend nearly $300 on an oscilloscope for only adjusting this one TV is not worth it-

Of course. I never said that I would. That's a popular oscilloscope around here and I have the possibility to borrow one.

Quote:
Originally Posted by avfanatic1 /forum/post/21426898


You can adjust all the other voltages with just a multimeter and a screwdriver, and for set-up and set-down just adjust in whatever direction makes it darker until you run into misfires or other issues.

I know. I just thought it would be interesting to check out the waveform and adjust it according to the service docs.
 
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