LG Plasma Panel tweaks for better blacks. - Page 9 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #241 of 1397 Old 11-29-2011, 04:56 AM
AVS Special Member
 
xrox's Avatar
 
Join Date: Feb 2003
Posts: 3,169
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 50
Quote:
Originally Posted by rob80b View Post

Just in theory, but seeing the tweak is just lowering the black level and not increasing the brightness, the panel (plasma) life should remain the same, and the fact that the APL is lower there should be less heat generated extending the life of the set.
And those who were not happy with the original black levels will probably now hold on to their sets that much longer.

Robert, If by APL you mean average picture level then how is this changed?

Over thinking, over analyzing separates the body from the mind
xrox is offline  
Sponsored Links
Advertisement
 
post #242 of 1397 Old 11-29-2011, 05:31 AM
AVS Special Member
 
Goatse's Avatar
 
Join Date: Jun 2007
Location: Pineapple under the sea
Posts: 3,875
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 12
Quote:
Originally Posted by rob80b View Post

Basic procedure, (not mine as I'll probably use a scope and voltage meter if I do proceed) as posted elsewhere.

"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."


Has anyone noticed using these settings that color banding is now more prominent and also seems like on certain scenes looks like there is worse line bleeding?
Goatse is offline  
post #243 of 1397 Old 11-29-2011, 06:40 AM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by xrox View Post

Robert, If by APL you mean average picture level then how is this changed?

Hi xrox

I’m just a layman here so I may have my terminology wrong, but I was thinking that if the overall panel luminance is lower (MLL?) with the tweak, the previously dark grey must have required more current to remain at that state and the new lower black less current. I do understand that lowering the black level does not mean darkening the overall picture (APL?) in fact shouldn’t it increase the apparent overall picture contrast so that the previous contrast and brightness settings could be lowered?

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #244 of 1397 Old 11-29-2011, 07:01 AM
AVS Special Member
 
xrox's Avatar
 
Join Date: Feb 2003
Posts: 3,169
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 50
Quote:
Originally Posted by rob80b View Post

Hi xrox

I'm just a layman here so I may have my terminology wrong, but I was thinking that if the overall panel luminance is lower (MLL?) with the tweak, the previously dark grey must have required more current to remain at that state and the new lower black less current. I do understand that lowering the black level does not mean darkening the overall picture (APL?) in fact shouldn't it increase the apparent overall picture contrast so that the previous contrast and brightness settings could be lowered?

No worries. I don't even own an LG. I'm just interested in PDP driving in general. APL is a percentage so you are correct that a reduction in black level will drop APL a very small amount. As for power and heat, it would be interesting if power consumption on a series of standard test patterns before and after adjustment was done.

Either way I think the physical panel itself (glass/phosphor) is perfectly safe regarding damage. The danger may lie in the driving boards, power supply, and other electrical components.

Over thinking, over analyzing separates the body from the mind
xrox is offline  
post #245 of 1397 Old 11-29-2011, 07:36 AM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by xrox View Post

No worries. I don't even own an LG. I'm just interested in PDP driving in general. APL is a percentage so you are correct that a reduction in black level will drop APL a very small amount. As for power and heat, it would be interesting if power consumption on a series of standard test patterns before and after adjustment was done.

Either way I think the physical panel itself (glass/phosphor) is perfectly safe regarding damage. The danger may lie in the driving boards, power supply, and other electrical components.

Component life is hit or miss, I've a number of synths, amps, tuners etc that still work fine after 30 even 40 years and had other well known brand names that died just after the one year warranty expired.
I would think the power supply would go first (if it goes) if we tweak it beyond the manufacturers power requirements but anything with lower DC voltages should last the life of the panel, I say should but unfortunately the race for cheaper and cheaper consumer electronics cause some devices to fail if we just look at them the wrong way.

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #246 of 1397 Old 11-29-2011, 07:49 AM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by Goatse View Post

Has anyone noticed using these settings that color banding is now more prominent and also seems like on certain scenes looks like there is worse line bleeding?

Hi Goatse,

It may be that we are being more critical and are noticing things that were there previously. I thought my tweaked PG25 was producing more banding but over the weekend I was scrutinizing my brothers Panasonic ST30 and became aware the ST30 was producing more noise near black and banding than my tweaked PG25 and stock PX950, , picture still looked very good though.

Second thought though, the improved contrast could well indeed make plasma banding more apparent.

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #247 of 1397 Old 11-29-2011, 09:20 AM
Member
 
Jimdish255's Avatar
 
Join Date: Jan 2008
Posts: 38
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Voz View Post

Big thanks for the report and the pictures. One question, did you follow the steps after "Actually done, but you can still try further:" as well?

Second question for losservatore is did you reset to original settings first before using the order of adjustments on the other site or add them to your existing ones? Instructions seemed to indicate the order being pretty specific for a reason.

Also interestring was an update or additional tweak mentioned later in the same thread:

After father's LG was adjusted, my turn came. With the additional reduction of down-VS - controls the base voltage of the electrode arrays of horizontal panels, and is relevant to the background brightness in black - has a black level of the Road map in the off state must be equated. At the same time the colors are brilliant and the picture become clearer.

...and later using a meter:

With Oszi Set_Dn / SET_UP adjusted anything with a multimeter. At the end of the VS have fundamental voltage (202V) manually with simultaneous viewing of two images (totally black and white and black +5%) decreased. The re-measurement of the voltage VS yielded a value of 192V.

The lower the voltage is visible with the naked eye.
Jimdish255 is offline  
post #248 of 1397 Old 11-29-2011, 10:25 AM
AVS Special Member
 
Goatse's Avatar
 
Join Date: Jun 2007
Location: Pineapple under the sea
Posts: 3,875
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 12
Quote:
Originally Posted by rob80b View Post

Hi Goatse,

It may be that we are being more critical and are noticing things that were there previously. I thought my tweaked PG25 was producing more banding but over the weekend I was scrutinizing my brothers Panasonic ST30 and became aware the ST30 was producing more noise near black and banding than my tweaked PG25 and stock PX950, , picture still looked very good though.

Second thought though, the improved contrast could well indeed make plasma banding more apparent.

you're probably right, I have been overly critical viewing the past week.
Goatse is offline  
post #249 of 1397 Old 11-29-2011, 10:48 AM
Member
 
derod68's Avatar
 
Join Date: Jul 2011
Posts: 171
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
"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."

Again, I have the above config on my PZ950 with set_up full throttle clockwise...no misfires. Has anyone done this exact tweak with the additional 2 pots with better results, or should I leave as is if too tricky/risky. I would like more pop if possible, now that blacks are deeper.

Thanks
derod68 is offline  
post #250 of 1397 Old 11-29-2011, 10:50 AM
Member
 
derod68's Avatar
 
Join Date: Jul 2011
Posts: 171
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Goatse View Post


Has anyone noticed using these settings that color banding is now more prominent and also seems like on certain scenes looks like there is worse line bleeding?

I haven't noticed any on the pz950 as of yet
derod68 is offline  
post #251 of 1397 Old 11-29-2011, 11:22 AM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by derod68 View Post

I would like more pop if possible, now that blacks are deeper.

Thanks


Hi derod

Don't go LCD on us now, the reason I initially went with Plasma a few years ago was the natural (life like) looking color pallet and contrast levels as apposed to the extreme contrast and artificially boosted color on LCDs, although they have improved.
Deep blacks, vibrant color and strong contrast can add to the wow factor but just lift your head up from the keyboard for a moment and look around, I do not believe you'll see real life that way.

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #252 of 1397 Old 11-29-2011, 12:28 PM
AVS Special Member
 
losservatore's Avatar
 
Join Date: Jan 2011
Location: Ohio
Posts: 2,950
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 99 Post(s)
Liked: 229
yes I went a little bit further with the pots to get better black levels,problems? well you will see some misfiring pixels in a cold start of your plasma like about 3 or 4 but after about 1 or 2 minutes the tv is back to normal,well another thin in order to get even more deeper blacks on my set I have to sacrifice two misfiringpixels,the two misfiringpixels turn back on in 24p mode so I can leave with that,remember that every plasma could behave different so you could get no missfiringpixels or could get one or two misfiringpixels, if you don't want to see then, just increase the levels of the set_down or set_up.

that behave of the 3 or 4 missfiring in cold start, started when I did the VZB POT
they go back to normal after 1 or 2 minutes if you dont want to see then just turn the VZB POT a little bit back almost to the normal position

The two missfiring pixels that doesn't go away is from the set_up and set_down If I want those back on I will have to go up with the set_up but the black levels will go up a little bit

BUT REMEMBER EVERY SINGLE PLASMA COULD BEHAVE DIFFERENT
maybe you wont get any misfiringpixels or you could get 1 or 2 thats if you want to go even lower.if you can leave with that no problem.

and remember that the 2 missfiring pixels they turn back on when I set the bd player to 24p mode.

I hope this will help

sorry for my english and if I miss some punctuation.

Panasonic 65VT60 / Marantz SR7005 / Marantz UD7007 /PSA XS30 /Revel Performa3 F206 / Revel Performa3 C205 / Sonos Connect/ Roku 3 / Amazon Fire tv / Xbox One / HTPC / Darbee 5000 /Sonos system for rooms/
losservatore is offline  
post #253 of 1397 Old 11-29-2011, 03:39 PM
Member
 
derod68's Avatar
 
Join Date: Jul 2011
Posts: 171
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by rob80b View Post


Hi derod

Don't go LCD on us now, the reason I initially went with Plasma a few years ago was the natural (life like) looking color pallet and contrast levels as apposed to the extreme contrast and artificially boosted color on LCDs, although they have improved.
Deep blacks, vibrant color and strong contrast can add to the wow factor but just lift your head up from the keyboard for a moment and look around, I do not believe you'll see real life that way.

Hi Rob,

I agree with you 110%, it's just I feel the tweaks might have made pics slightly duller and wondering if any of the other 2 most recently mentioned pots, other than the 4 I used, can directly influence this. Again, maybe it's just me and admittedly have become SLIGHTLY OBSESSED (wife gonna do an intervention ) in pursuit of the most optimal PQ I can get.
derod68 is offline  
post #254 of 1397 Old 11-29-2011, 04:50 PM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by derod68 View Post

Hi Rob,

I agree with you 110%, it's just I feel the tweaks might have made pics slightly duller and wondering if any of the other 2 most recently mentioned pots, other than the 4 I used, can directly influence this. Again, maybe it's just me and admittedly have become SLIGHTLY OBSESSED (wife gonna do an intervention ) in pursuit of the most optimal PQ I can get.

Hi derod,

I'm mostly coming from the audio side of things, some days the system sounds great, other days for no obvious reason it might sound like crap, I'm sure this endeavor is no different.
Still I'm grateful to get as much feed back as possible and if we get repeated observations we might nail this puppy down to a science, but I'd love to get a tech well versed in plasma panels on board, right now i feel we're like a bunch of cowboys twistin and turnin dials when there's a straight and logical approach to get the results we're aiming for.

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #255 of 1397 Old 11-29-2011, 05:37 PM
Advanced Member
 
Emig5m's Avatar
 
Join Date: Jun 2006
Location: NJ, USA
Posts: 935
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 15
Quote:
Originally Posted by Goatse View Post

Has anyone noticed using these settings that color banding is now more prominent and also seems like on certain scenes looks like there is worse line bleeding?

Nope. Line bleeding is nearly invisible on my set and didn't notice anything out of the norm with color banding.
Emig5m is offline  
post #256 of 1397 Old 11-29-2011, 05:37 PM
Advanced Member
 
Emig5m's Avatar
 
Join Date: Jun 2006
Location: NJ, USA
Posts: 935
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 15
Quote:
Originally Posted by rob80b View Post

Hi xrox

I'm just a layman here so I may have my terminology wrong, but I was thinking that if the overall panel luminance is lower (MLL?) with the tweak, the previously dark grey must have required more current to remain at that state and the new lower black less current. I do understand that lowering the black level does not mean darkening the overall picture (APL?) in fact shouldn't it increase the apparent overall picture contrast so that the previous contrast and brightness settings could be lowered?

I had to lower my contrast, but raise my brightness.
Emig5m is offline  
post #257 of 1397 Old 11-29-2011, 08:29 PM
Member
 
derod68's Avatar
 
Join Date: Jul 2011
Posts: 171
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Emig5m View Post


I had to lower my contrast, but raise my brightness.

Diddo. I don't see how anyone didn't have to raise brightness after pots tweak. Otherwise missing details in dark areas. Even after using Wizard (expert1), still have to raise brightness a couple a notches.
derod68 is offline  
post #258 of 1397 Old 11-30-2011, 03:19 AM
Advanced Member
 
MitchR's Avatar
 
Join Date: Jan 2007
Posts: 635
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Raising the brightness level increases PWM noise, which is still a problem with LG plasmas.

The one thing that kind of bothers me with these LG plasmas is that when you're watching movies with black bars, the brightness of the picture kind of crawls into the black bars, making the top and bottom of the bars glow, which is pretty annoying when presented a full black screen.

I had some occasional moments where on startup, the screen is showing inky spots of pixels not being fired. Waiting for the power supply to reach optimum temperature, it all dissappears. Setting the POTS back to stock level does not fix this, so I have to live with that. Overall though, the picture is much much better than before.
MitchR is offline  
post #259 of 1397 Old 11-30-2011, 03:21 AM
Advanced Member
 
MitchR's Avatar
 
Join Date: Jan 2007
Posts: 635
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by rob80b View Post

Just in theory, but seeing the tweak is just lowering the black level and not increasing the brightness, the panel (plasma) life should remain the same, and the fact that the APL is lower there should be less heat generated extending the life of the set.
And those who were not happy with the original black levels will probably now hold on to their sets that much longer.

You are correct. Tweaking the POTS does lower the generated heat from the panel. It's really a BIG difference with mine, I can now hold my hand on the back without getting burned
MitchR is offline  
post #260 of 1397 Old 11-30-2011, 05:03 AM
Voz
Member
 
Voz's Avatar
 
Join Date: Jul 2008
Posts: 93
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by MitchR View Post

The one thing that kind of bothers me with these LG plasmas is that when you're watching movies with black bars, the brightness of the picture kind of crawls into the black bars, making the top and bottom of the bars glow, which is pretty annoying when presented a full black screen.

Which models? I have a PK950 and haven't noticed this.
Voz is offline  
post #261 of 1397 Old 11-30-2011, 05:24 AM
AVS Special Member
 
Goatse's Avatar
 
Join Date: Jun 2007
Location: Pineapple under the sea
Posts: 3,875
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 12
Quote:
Originally Posted by Voz View Post

Which models? I have a PK950 and haven't noticed this.

i have a pk950, the black bars always glowed a bit gray. Really noticeable in dark scenes.
Goatse is offline  
post #262 of 1397 Old 11-30-2011, 09:44 AM
Advanced Member
 
MitchR's Avatar
 
Join Date: Jan 2007
Posts: 635
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Voz View Post

Which models? I have a PK950 and haven't noticed this.

LG 50PV250 (EU model)
MitchR is offline  
post #263 of 1397 Old 11-30-2011, 10:13 AM
Advanced Member
 
Turrican4D's Avatar
 
Join Date: Dec 2009
Posts: 606
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 11
Quote:
Originally Posted by derod68 View Post

Diddo. I don't see how anyone didn't have to raise brightness after pots tweak. Otherwise missing details in dark areas.

I did not change my brightnesssetting at all.

It woulkdn't be a good idea to do so, when you had the optimal blacklevelpoint already beforce the procedure, i.e. Black at "16" and "17" the first shade with pictureinformation.

Raising the brightness after that just sets the wrong blacklevelpoint and give you noise in shades that should be black.

With the potiruning you don't lose shadowdetail, actually it becomes more visible. The measured gamma of IRE5 rises (cause the colorimeter measures the noise and the black areas between the pwm spikes), which is a good thing, cause otherwise you would only reach 1.92 at IRE5, after the tweak I have 2.12

Also, the combination of the brightnesssetting and the R, G, B-setting of IRE5 is very uhm... special. There only exist one sweet spot, at which all shades at the very low end of the greyscale become different enough to render all detail.

On my german PK350 (the same as US PK550) it is "Brightness 54; Gamma High; IRE5 +5 -1 -2
Turrican4D is offline  
post #264 of 1397 Old 11-30-2011, 12:43 PM
AVS Special Member
 
losservatore's Avatar
 
Join Date: Jan 2011
Location: Ohio
Posts: 2,950
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 99 Post(s)
Liked: 229
well I don't have anything bad to said about this procedure,I just see awesome results in front of me...

Panasonic 65VT60 / Marantz SR7005 / Marantz UD7007 /PSA XS30 /Revel Performa3 F206 / Revel Performa3 C205 / Sonos Connect/ Roku 3 / Amazon Fire tv / Xbox One / HTPC / Darbee 5000 /Sonos system for rooms/
losservatore is offline  
post #265 of 1397 Old 11-30-2011, 01:08 PM
AVS Special Member
 
rpauls's Avatar
 
Join Date: Nov 2006
Posts: 1,192
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Rob/Others

It has been mentioned a few times in this thread that using an oscilloscope would make the adjustment procedure easier and potentially more effective. I wonder if I could get some details as to how one would proceed using a scope.

The instructions below for adjusting Vs and Va using a voltmeter are clear, but the procedure using the scope is not. I am not sure what signal is being displayed in the diagrams where set UP/DN are being adjusted. Where does this signal appear on the board? What are the volts/div and sec/div on the axes? Are there any more details of the procedure in the training manual you are posting from?

Thanks for any help, and for collecting the various postings into this amazing thread.

Rich


Quote:
Originally Posted by rob80b View Post

Hi xrox


I mentioned the VA and VS as you stated above in another thread, I was trying to simplify the initial voltage driving the panel but I like your explanation.


Thanks





rpauls is offline  
post #266 of 1397 Old 11-30-2011, 01:47 PM
Member
 
harvro01's Avatar
 
Join Date: Jan 2010
Location: Coalhurst, AB
Posts: 52
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
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.
harvro01 is offline  
post #267 of 1397 Old 11-30-2011, 02:06 PM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by rpauls View Post

Rob/Others

It has been mentioned a few times in this thread that using an oscilloscope would make the adjustment procedure easier and potentially more effective. I wonder if I could get some details as to how one would proceed using a scope.

The instructions below for adjusting Vs and Va using a voltmeter are clear, but the procedure using the scope is not. I am not sure what signal is being displayed in the diagrams where set UP/DN are being adjusted. Where does this signal appear on the board? What are the volts/div and sec/div on the axes? Are there any more details of the procedure in the training manual you are posting from?

Thanks for any help, and for collecting the various postings into this amazing thread.

Rich

Hi Rich

Depending on which model you have check the LG site http://136.166.4.200/SubPages/Directview_PDP.htm for the training manual, the contact points for connecting a scope are shown clearly for each model. The scope would be used to monitor the wave-forms on the Y Sustain board and should give you a direct correlation to the pot adjustments on an x/y axis, basically the duty cycles.
I was going to use my oscilloscope when doing my PG25 but in the end I just winged it, I may still use it though for my PX950 if and when I get it off the wall.

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #268 of 1397 Old 11-30-2011, 02:17 PM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by harvro01 View Post

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

Thank harvro

Great to hear you used the manual as a guide and a nice explanation on the procedure, keep us up to date on any changes.
ps, I quoted your procedure in the first post.
http://www.avsforum.com/avs-vb/showt...php?p=21202524

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #269 of 1397 Old 11-30-2011, 02:25 PM - Thread Starter
AVS Special Member
 
rob80b's Avatar
 
Join Date: Sep 2007
Location: Toronto, Ontario
Posts: 1,515
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 30
Quote:
Originally Posted by harvro01 View Post

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.

The German site discovered most of the panel stickers were off, in fact they were calibrated to the voltages in the manual and not to individual panel requirements, so much for assembly line testing procedures.
Which again explains the discrepancies in reported black levels on LG plasmas.

Robert
Toronto, Ontario

 

https://myspace.com/151752802/videos

rob80b is online now  
post #270 of 1397 Old 11-30-2011, 03:43 PM
Member
 
Tadream's Avatar
 
Join Date: Aug 2010
Location: The Netherlands
Posts: 19
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Turrican4D View Post

I did not change my brightnesssetting at all.

On my german PK350 (the same as US PK550) it is "Brightness 54; Gamma High; IRE5 +5 -1 -2

I also didn't had to alter the brightness, mine's at 50. I guess it depends on how you setup the TV. From out of my head I have Gamma at medium.
The black is indeed deeper and it doesn't get crushed. Watching a good HD documentary on Discovery HD or Nat Geo HD you can almost touch the grass/water/ice.
I didn't touch the pots on the powersupply (VA etc), mostly did tweaking on Setp_Up, Set_Down and Vy.
The only thing I notice (which was mentioned by some) is that when I just turn on the TV I see pixels (some sort of image retention) but as soon as there is an image it's gone and I don't see any weirdness when there's something on. I can live with that.
Tadream is offline  
Reply Plasma Flat Panel Displays

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off