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Samsung Plasma Panel tweaks for better blacks. - Page 2

post #31 of 366
Quote:
Originally Posted by zoyd View Post


Mine are similar, when I reduce Vs to 199 and increase Vsc to -180 the mll dropped by 0.003 ftL

Ok cheers, will give it a shot. I missed the Vscan pot during my initial tweaks. Maybe it's totally out of whack. My previous peeler had significantly better blacks than the replacement which has a substantial glow to it.
post #32 of 366
The Panel tweaks will work on my Samsung plasma PN51D490 series?
post #33 of 366
Thread Starter 
Yes, the trim pots should be present on all 400 and 500 level models
post #34 of 366
Zoyd Hello and congratulations!

Do you think this tweak works well even on the European models?
My tv is a 51D8000.

Thank you.
post #35 of 366
I'm really interested in doing this on my 51D550, I'll need to read up on the LG thread.

What I can't understand is, if these TVs can be tweaked manually for really great blacks, why weren't they in the factory? I thought MLL was a bragging right for these companies, but they send them out with higher blacks the set can be trimmed to.

Was there any sort of benefit for the default settings?
post #36 of 366
Thread Starter 
Quote:
Originally Posted by Roby7108 View Post

Zoyd Hello and congratulations!

Do you think this tweak works well even on the European models?
My tv is a 51D8000.

Thank you.

I think it will work exactly the same on EU models since they use the same hardware and waveforms.

@staylorist: My thoughts here are that Samsung built in a lot of margin to ensure long life/trouble-free performance regarding pixel misfires. So we are pushing that margin toward better black performance. The trade off will be that over time you may have to recover some of that margin (re-tweak) if pixel misfires worsen. (in other words, it's not a free lunch! ) I'm not sure why the smaller panels have so much margin compared to the larger, they should have been able to get these under 0.01 ftL at the factory.
post #37 of 366
Quote:
Originally Posted by zoyd View Post

I think it will work exactly the same on EU models since they use the same hardware and waveforms.

Thanks Zoyd!
How to set the trim pots VSC and VsVa related to the voltage?
I think the European models have different voltages from the U.S....
post #38 of 366
Thread Starter 
Quote:
Originally Posted by Roby7108 View Post

Thanks Zoyd!
How to set the trim pots VSC and VsVa related to the voltage?
I think the Italian models have different voltages from the U.S....

Biggest benefit is from reducing the flat-top portion of the rising pulse using Yrr, small rotation clockwise and measure reduction. If you want to try adjusting voltages as well, look to see what is printed on the sticker inside the chassis and reduce the value for Vs on the power supply board (example: 205V to 200V) and increase the value for Ysc on the Y-Scan board (example: -190V to -180V). After you have made adjustments check using display using a whitewash pattern (or grayscale ramps) to see if you have any pixel misfires (seen as black or color speckles)
post #39 of 366
Thank you, very very kind.
When I find the courage to make the tweak (I think soon) I will send my comments.
post #40 of 366
Quote:
Originally Posted by zoyd View Post

Biggest benefit is from reducing the flat-top portion of the rising pulse using Yrr, small rotation clockwise and measure reduction. If you want to try adjusting voltages as well, look to see what is printed on the sticker inside the chassis and reduce the value for Vs on the power supply board (example: 205V to 200V) and increase the value for Ysc on the Y-Scan board (example: -190V to -180V). After you have made adjustments check using display using a whitewash pattern (or grayscale ramps) to see if you have any pixel misfires (seen as black or color speckles)

Hi Zoyd

Some of the tweakers on the Lgs discovered their factory settings were off from their panel's label values, which are unique to each panel, and by readjusting with a multimeter to those written for their specific panel they actually achieved better black levels without misfires while adjusting the Set_up (Yrr for Samsung). But again all panels are different and results will vary, at least with the LGs, I'm curious if the same applies to the Samsung panels.
post #41 of 366
Thread Starter 
yeah, my experience was the opposite. The voltages were spot on with reference to the sticker values and reducing two of them (sustain and scan) resulted in minor improvements to mll. If I start to see funky behavior I'll set them back to factory.
post #42 of 366
Has anyone tried adjusting Yrr on a 51D with no adjustment to voltages to see if the improvement is completely independent? I'm not sure I want to mess with miss-firing pixels...
post #43 of 366
Thread Starter 
With both adjustments there is the potential for pixel misfiring. One adjustment reduces the voltage supplied to initialize the pixel, the other (Yrr) reduces the duration that voltage is applied. In both cases you are provided less energy to initialize. Yrr had a larger effect because it removes more energy so it will also have a higher chance of pixel misfires. I think it's a good idea to start with voltages at factory settings and adjust Yrr by itself. I just did both to push it as far as I could and observe the results. The only pixel misfires I see are on a cold start (several observed in first black screen after turn on). After that it's been clean.
post #44 of 366
is it true good things come in 3? first the FBr thread, now this. what's next zoyd? this is great stuff. so how do you know what the level of the voltage is when turning it?

now if I can find out if my 59D6500 has the Yrr adjustment.
post #45 of 366
Thread Starter 
There are test pads for all the adjustments (see pictures in 1st post). standard multimeter is fine for Vs and Vsc, you'll need a scope if you want to see Yrr adjustments (I didn't use one)
post #46 of 366
So I've improved my 64 d8000 MLL by a slight but noticeable amount. I measured the voltages but I threw out the blasted note during cleanup.

I achieved the optimal by full clockwise Vscan and then minimizing VS (anti clockwise) to just above point of misfire.

How I long for a discovery of how to adjust the Yrr on the 64" (and 59" for others). Here's hoping, till then it's as good as its going to be.

Thanks Zoyd. Your contribution to this scene cannot be underestimated. It's also interesting looking at our debate in the calibration thread back in October
post #47 of 366
Thread Starter 
Quote:
Originally Posted by muzzakus View Post

It's also interesting looking at our debate in the calibration thread back in October

yes, I thought about that after I did the tweak. Turns out your intuition was better than my pessimism. I really didn't think there would be this amount of latitude in the initialization pulse without generating undesirable effects. Sorry about the lack of adjustment on your set.
post #48 of 366
As I understand this, the optimal performance (MLL) will be achieved by minimizing the energy being put into each cell to a point just above misfires. As the cells age, they'll begin requiring more energy to avoid misfire, and we'll have to tweak the settings again. Do I have that right?

Assuming I do have that right, here's my question. By running on the ragged edge here, we're surely putting our displays in a position where misfires will be more frequent. Samsung apparently set these things from the factory to NEVER misfire. If we set it and NEVER misfire, then we aren't on the edge and we haven't turned things as far as we could have. So now that we've increased the likelihood of occasional (or at least eventual) misfires, does this have any side effects? Do misfires cause any damage or prematurely age the cell?
post #49 of 366
Thread Starter 
Quote:
Originally Posted by pitviper33 View Post

As I understand this, the optimal performance (MLL) will be achieved by minimizing the energy being put into each cell to a point just above misfires. As the cells age, they'll begin requiring more energy to avoid misfire, and we'll have to tweak the settings again. Do I have that right?

yes, the initialization stage primes the cell so that when sustain voltage is applied the gas will breakdown and create the plasma. As cell coatings age they become less efficient and harder to prime.

Quote:
Assuming I do have that right, here's my question. By running on the ragged edge here, we're surely putting our displays in a position where misfires will be more frequent. Samsung apparently set these things from the factory to NEVER misfire. If we set it and NEVER misfire, then we aren't on the edge and we haven't turned things as far as we could have. So now that we've increased the likelihood of occasional (or at least eventual) misfires, does this have any side effects? Do misfires cause any damage or prematurely age the cell?

Other than a visual nuisance I can't see where not turning on a few random pixels once in awhile will have any long term effect at all. I think Samsung sets it this way for the reason you state, so that the user will never ever see a pixel misfire.
post #50 of 366
There was a time I did this on my old CRT TV...ages ago...a LG unit (Lucky Goldstar)
post #51 of 366
Thread Starter 
so are you going to check out if your 6500 has the adjustments?
post #52 of 366
Hi zoyd

Here are some sheets from LG's PK950 which might shed some light on the Samsungs until someone posts info from the Tech Manuals, technology is similar, terminology may be different.



post #53 of 366
Quote:
Originally Posted by chikoo View Post

There was a time I did this on my old CRT TV...ages ago...a LG unit (Lucky Goldstar)

Quote:
Originally Posted by zoyd View Post

so are you going to check out if your 6500 has the adjustments?

nah...this TV is quite new and I don't want to open up the rear panel...just yet
post #54 of 366
Hi,
I am replacing a PS51d550 that was damaged in an accident with a 59"next week . Has anyone tweaked a 59D550 yet? And is there anyway to open the panel without voiding the warranty? Thanks
post #55 of 366
Thread Starter 
no reports yet on 59D550. Assuming you don't damage anything, opening your panel is not going to void anything but if damage occurs as a result of your tweaking, that is where you will run into trouble.
post #56 of 366
Thanks Zoyd, Hopefully the TV has YRR adjustments. So if I follow your guidlines, use plastic screw drivers manage not to touch anything I should be alright?
post #57 of 366
Thread Starter 
yes, the adjustments have a very limited range so you won't stress the system in any way. Plastic screwdriver is essential, the easiest way to damage a component (or yourself) is to slip and short something to ground with a metal screwdriver. Also be mindful of static electricity, this can damage components even when the TV is off. Wear a grounding wrist strap if you want to be extra cautious about static discharge.
post #58 of 366
I will give this a go in a couple of weeks once Ive broken the panel in and hopefully someone would have tweaked 59d550. Thanks again
post #59 of 366
Zoyd,

This may sound very noobish, however should this adjustment be done only if you have a calibrating tool?

I do not have any calibrating tools and usually just play with setting I see posted on here. BTW, I also have a 51d8000 and very excited to see this sort of level of tweaking going on. I was big into tweaking cell phones and tunes on turbo cars. I am pretty handy and can figure things out, I just don't know If I should not even bother with this without a calibrating tool

Cheers
post #60 of 366
Thread Starter 
nope, IMO the tweak is worth it even if you can't measure the final mll. You'll see the difference immediately on the 51"ers. Just rotate Yrr CW until you see patches of misfires in the scrolling grey pattern (under menu->system->screen burn protection) and then back off a bit until it clears up.
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